diff options
Diffstat (limited to 'documentation/content/en/books/developers-handbook')
38 files changed, 20329 insertions, 321 deletions
diff --git a/documentation/content/en/books/developers-handbook/_index.adoc b/documentation/content/en/books/developers-handbook/_index.adoc index add9336ec8..c8de6b25da 100644 --- a/documentation/content/en/books/developers-handbook/_index.adoc +++ b/documentation/content/en/books/developers-handbook/_index.adoc @@ -2,7 +2,7 @@ title: FreeBSD Developers' Handbook authors: - author: The FreeBSD Documentation Project -copyright: 1995-2021 The FreeBSD Documentation Project +copyright: 1995-2023 The FreeBSD Documentation Project description: For people who want to develop software for FreeBSD (and not just people who are developing FreeBSD itself) trademarks: ["freebsd", "apple", "ibm", "ieee", "intel", "linux", "microsoft", "opengroup", "sun", "general"] next: books/developers-handbook/parti @@ -54,6 +54,6 @@ Many sections do not yet exist and some of those that do exist need to be update If you are interested in helping with this project, send email to the {freebsd-doc}. The latest version of this document is always available from the link:https://www.FreeBSD.org[FreeBSD World Wide Web server]. -It may also be downloaded in a variety of formats and compression options from the link:https://download.freebsd.org/doc/[FreeBSD FTP server] or one of the numerous extref:{handbook}[mirror sites, mirrors-ftp]. +It may also be downloaded in a variety of formats and compression options from the link:https://download.freebsd.org/doc/[FreeBSD download server] or one of the numerous extref:{handbook}[mirror sites, mirrors]. ''' diff --git a/documentation/content/en/books/developers-handbook/_index.po b/documentation/content/en/books/developers-handbook/_index.po new file mode 100644 index 0000000000..f0e9b26e16 --- /dev/null +++ b/documentation/content/en/books/developers-handbook/_index.po @@ -0,0 +1,59 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-07-07 23:23-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: description +#: documentation/content/en/books/developers-handbook/_index.adoc:1 +#, no-wrap +msgid "For people who want to develop software for FreeBSD (and not just people who are developing FreeBSD itself)" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/_index.adoc:1 +#: documentation/content/en/books/developers-handbook/_index.adoc:17 +#, no-wrap +msgid "FreeBSD Developers' Handbook" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/_index.adoc:50 +msgid "Abstract" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/_index.adoc:55 +msgid "" +"Welcome to the Developers' Handbook. This manual is a _work in progress_ " +"and is the work of many individuals. Many sections do not yet exist and " +"some of those that do exist need to be updated. If you are interested in " +"helping with this project, send email to the {freebsd-doc}." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/_index.adoc:58 +msgid "" +"The latest version of this document is always available from the link:" +"https://www.FreeBSD.org[FreeBSD World Wide Web server]. It may also be " +"downloaded in a variety of formats and compression options from the link:" +"https://download.freebsd.org/doc/[FreeBSD download server] or one of the " +"numerous extref:{handbook}[mirror sites, mirrors]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/_index.adoc:59 +msgid "'''" +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/bibliography/_index.adoc b/documentation/content/en/books/developers-handbook/bibliography/_index.adoc index 07de2384a8..18ded77fb3 100644 --- a/documentation/content/en/books/developers-handbook/bibliography/_index.adoc +++ b/documentation/content/en/books/developers-handbook/bibliography/_index.adoc @@ -1,16 +1,16 @@ --- -title: Appendices +title: Bibliography prev: books/developers-handbook/partv description: FreeBSD Developers Handbook Bibliography tags: ["FreeBSD Developers' Handbook", "bibliography"] showBookMenu: true weight: 17 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/bibliography/" --- [appendix] [[bibliography]] -= Appendices += Bibliography :doctype: book :toc: macro :toclevels: 1 diff --git a/documentation/content/en/books/developers-handbook/bibliography/_index.po b/documentation/content/en/books/developers-handbook/bibliography/_index.po new file mode 100644 index 0000000000..c56abf3d9c --- /dev/null +++ b/documentation/content/en/books/developers-handbook/bibliography/_index.po @@ -0,0 +1,75 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2024-01-17 20:34-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: description +#: documentation/content/en/books/developers-handbook/bibliography/_index.adoc:1 +#, no-wrap +msgid "FreeBSD Developers Handbook Bibliography" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/bibliography/_index.adoc:1 +#: documentation/content/en/books/developers-handbook/bibliography/_index.adoc:13 +#, no-wrap +msgid "Bibliography" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/bibliography/_index.adoc:51 +msgid "" +"[[COD,1]] [1] Dave A Patterson and John L Hennessy. Copyright(R) 1998 Morgan " +"Kaufmann Publishers, Inc. 1-55860-428-6. Morgan Kaufmann Publishers, Inc. " +"Computer Organization and Design. The Hardware / Software Interface. 1-2." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/bibliography/_index.adoc:53 +msgid "" +"[[APUE, 2]] [2] W. Richard Stevens. Copyright(R) 1993 Addison Wesley " +"Longman, Inc. 0-201-56317-7. Addison Wesley Longman, Inc. Advanced " +"Programming in the Unix Environment. 1-2." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/bibliography/_index.adoc:55 +msgid "" +"[[DIFOS, 3]] [3] Marshall Kirk McKusick and George Neville-Neil. " +"Copyright(R) 2004 Addison-Wesley. 0-201-70245-2. Addison-Wesley. The Design " +"and Implementation of the FreeBSD Operating System. 1-2." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/bibliography/_index.adoc:57 +msgid "" +"[[Phrack, 4]] [4] Aleph One. Phrack 49; \"Smashing the Stack for Fun and " +"Profit\"." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/bibliography/_index.adoc:59 +msgid "" +"[[StackGuard, 5]] [5] Chrispin Cowan, Calton Pu, and Dave Maier. StackGuard; " +"Automatic Adaptive Detection and Prevention of Buffer-Overflow Attacks." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/bibliography/_index.adoc:61 +msgid "" +"[[OpenBSD, 6]] [6] Todd Miller and Theo de Raadt. strlcpy and strlcat -- " +"consistent, safe string copy and concatenation." +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/book.adoc b/documentation/content/en/books/developers-handbook/book.adoc index 06061218ff..63a89edddc 100644 --- a/documentation/content/en/books/developers-handbook/book.adoc +++ b/documentation/content/en/books/developers-handbook/book.adoc @@ -2,7 +2,7 @@ title: FreeBSD Developers' Handbook authors: - author: The FreeBSD Documentation Project -copyright: 1995-2021 The FreeBSD Documentation Project +copyright: 1995-2023 The FreeBSD Documentation Project description: For people who want to develop software for FreeBSD (and not just people who are developing FreeBSD itself) trademarks: ["freebsd", "apple", "ibm", "ieee", "intel", "linux", "microsoft", "opengroup", "sun", "general"] tags: ["FreeBSD Developers' Handbook"] @@ -53,7 +53,7 @@ Many sections do not yet exist and some of those that do exist need to be update If you are interested in helping with this project, send email to the {freebsd-doc}. The latest version of this document is always available from the link:https://www.FreeBSD.org[FreeBSD World Wide Web server]. -It may also be downloaded in a variety of formats and compression options from the link:https://download.freebsd.org/doc/[FreeBSD FTP server] or one of the numerous extref:{handbook}[mirror sites, mirrors-ftp]. +It may also be downloaded in a variety of formats and compression options from the link:https://download.freebsd.org/doc/[FreeBSD download server] or one of the numerous extref:{handbook}[mirror sites, mirrors]. ''' diff --git a/documentation/content/en/books/developers-handbook/book.po b/documentation/content/en/books/developers-handbook/book.po new file mode 100644 index 0000000000..3cf61902ab --- /dev/null +++ b/documentation/content/en/books/developers-handbook/book.po @@ -0,0 +1,59 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-07-07 23:23-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: description +#: documentation/content/en/books/developers-handbook/book.adoc:1 +#, no-wrap +msgid "For people who want to develop software for FreeBSD (and not just people who are developing FreeBSD itself)" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/book.adoc:1 +#: documentation/content/en/books/developers-handbook/book.adoc:12 +#, no-wrap +msgid "FreeBSD Developers' Handbook" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/book.adoc:49 +msgid "Abstract" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/book.adoc:54 +msgid "" +"Welcome to the Developers' Handbook. This manual is a _work in progress_ " +"and is the work of many individuals. Many sections do not yet exist and " +"some of those that do exist need to be updated. If you are interested in " +"helping with this project, send email to the {freebsd-doc}." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/book.adoc:57 +msgid "" +"The latest version of this document is always available from the link:" +"https://www.FreeBSD.org[FreeBSD World Wide Web server]. It may also be " +"downloaded in a variety of formats and compression options from the link:" +"https://download.freebsd.org/doc/[FreeBSD download server] or one of the " +"numerous extref:{handbook}[mirror sites, mirrors]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/book.adoc:59 +msgid "'''" +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/introduction/_index.adoc b/documentation/content/en/books/developers-handbook/introduction/_index.adoc index e98ecf0934..29f1dbdd5f 100644 --- a/documentation/content/en/books/developers-handbook/introduction/_index.adoc +++ b/documentation/content/en/books/developers-handbook/introduction/_index.adoc @@ -9,7 +9,7 @@ description: Introduction to the FreeBSD Developers Handbook tags: ["introduction", "Developing on FreeBSD", "BSD Vision", "Architectural Guidelines"] showBookMenu: true weight: 2 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/introduction/" --- [[introduction]] @@ -86,72 +86,6 @@ From Scheifler & Gettys: "X Window System" [[introduction-layout]] == The Layout of /usr/src -The complete source code to FreeBSD is available from our public repository. -The source code is normally installed in [.filename]#/usr/src# which contains the following subdirectories: - -[.informaltable] -[cols="1,1", frame="none", options="header"] -|=== -| Directory -| Description - -|[.filename]#bin/# -|Source for files in [.filename]#/bin# - -|[.filename]#cddl/# -|Utilities covered by the Common Development and Distribution License - -|[.filename]#contrib/# -|Source for files from contributed software - -|[.filename]#crypto/# -|Cryptographical sources - -|[.filename]#etc/# -|Source for files in [.filename]#/etc# - -|[.filename]#gnu/# -|Utilities covered by the GNU Public License - -|[.filename]#include/# -|Source for files in [.filename]#/usr/include# - -|[.filename]#kerberos5/# -|Source for Kerberos version 5 - -|[.filename]#lib/# -|Source for files in [.filename]#/usr/lib# - -|[.filename]#libexec/# -|Source for files in [.filename]#/usr/libexec# - -|[.filename]#release/# -|Files required to produce a FreeBSD release - -|[.filename]#rescue/# -|Build system for the [.filename]#/rescue# utilities - -|[.filename]#sbin/# -|Source for files in [.filename]#/sbin# - -|[.filename]#secure/# -|Contributed cryptographic sources - -|[.filename]#share/# -|Source for files in [.filename]#/usr/share# - -|[.filename]#sys/# -|Kernel source files - -|[.filename]#tests/# -|The FreeBSD test suite - -|[.filename]#tools/# -|Tools used for maintenance and testing of FreeBSD - -|[.filename]#usr.bin/# -|Source for files in [.filename]#/usr/bin# - -|[.filename]#usr.sbin/# -|Source for files in [.filename]#/usr/sbin# -|=== +The complete source code for FreeBSD is available from our link:https://cgit.freebsd.org/src/[public Git repository]. +The source code is normally installed in [.filename]#/usr/src#. +The layout of the source tree is described by the top-level link:https://cgit.freebsd.org/src/tree/README.md[README.md] file. diff --git a/documentation/content/en/books/developers-handbook/introduction/_index.po b/documentation/content/en/books/developers-handbook/introduction/_index.po new file mode 100644 index 0000000000..a489b85abe --- /dev/null +++ b/documentation/content/en/books/developers-handbook/introduction/_index.po @@ -0,0 +1,153 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2023-06-19 21:08-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: description +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:1 +#, no-wrap +msgid "Introduction to the FreeBSD Developers Handbook" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:1 +#, no-wrap +msgid "Chapter 1. Introduction" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:16 +#, no-wrap +msgid "Introduction" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:54 +#, no-wrap +msgid "Developing on FreeBSD" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:59 +msgid "" +"So here we are. System all installed and you are ready to start " +"programming. But where to start? What does FreeBSD provide? What can it do " +"for me, as a programmer?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:65 +msgid "" +"These are some questions which this chapter tries to answer. Of course, " +"programming has different levels of proficiency like any other trade. For " +"some it is a hobby, for others it is their profession. The information in " +"this chapter might be aimed toward the beginning programmer; indeed, it " +"could serve useful for the programmer unfamiliar with the FreeBSD platform." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:67 +#, no-wrap +msgid "The BSD Vision" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:70 +msgid "" +"To produce the best UNIX(R) like operating system package possible, with due " +"respect to the original software tools ideology as well as usability, " +"performance and stability." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:72 +#, no-wrap +msgid "Architectural Guidelines" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:75 +msgid "Our ideology can be described by the following guidelines" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:77 +msgid "" +"Do not add new functionality unless an implementor cannot complete a real " +"application without it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:78 +msgid "" +"It is as important to decide what a system is not as to decide what it is. " +"Do not serve all the world's needs; rather, make the system extensible so " +"that additional needs can be met in an upwardly compatible fashion." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:79 +msgid "" +"The only thing worse than generalizing from one example is generalizing from " +"no examples at all." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:80 +msgid "" +"If a problem is not completely understood, it is probably best to provide no " +"solution at all." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:81 +msgid "" +"If you can get 90 percent of the desired effect for 10 percent of the work, " +"use the simpler solution." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:82 +msgid "Isolate complexity as much as possible." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:83 +msgid "" +"Provide mechanism, rather than policy. In particular, place user interface " +"policy in the client's hands." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:85 +msgid "From Scheifler & Gettys: \"X Window System\"" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:87 +#, no-wrap +msgid "The Layout of /usr/src" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/introduction/_index.adoc:91 +msgid "" +"The complete source code for FreeBSD is available from our link:https://cgit." +"freebsd.org/src/[public Git repository]. The source code is normally " +"installed in [.filename]#/usr/src#. The layout of the source tree is " +"described by the top-level link:https://cgit.freebsd.org/src/tree/README." +"md[README.md] file." +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/ipv6/_index.adoc b/documentation/content/en/books/developers-handbook/ipv6/_index.adoc index ffad0eae89..e24d7321b0 100644 --- a/documentation/content/en/books/developers-handbook/ipv6/_index.adoc +++ b/documentation/content/en/books/developers-handbook/ipv6/_index.adoc @@ -8,7 +8,7 @@ description: IPv6 Internals tags: ["IPv6", "FreeBSD"] showBookMenu: true weight: 10 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/ipv6/" --- [[ipv6]] @@ -220,7 +220,7 @@ Programs that use these APIs have to be prepared about differences in kernels an When you specify scoped address to the command line, NEVER write the embedded form (such as ff02:1::1 or fe80:2::fedc). This is not supposed to work. -Always use standard form, like ff02::1 or fe80::fedc, with command line option for specifying interface (like `ping6 -I ne0 ff02::1`). +Always use standard form, like ff02::1 or fe80::fedc, with command line option for specifying interface (like `ping -6 -I ne0 ff02::1`). In general, if a command does not have command line option to specify outgoing interface, that command is not ready to accept scoped address. This may seem to be opposite from IPv6's premise to support "dentist office" situation. We believe that specifications need some improvements for this. @@ -380,13 +380,13 @@ If you want to try jumbo payloads, you first have to reconfigure the kernel so t and recompile the new kernel. -Then you can test jumbo payloads by the man:ping6[8] command with -b and -s options. +Then you can test jumbo payloads by the man:ping[8] command with -6, -b and -s options. The -b option must be specified to enlarge the size of the socket buffer and the -s option specifies the length of the packet, which should be more than 65,535. For example, type as follows: [source,bash] .... -% ping6 -b 70000 -s 68000 ::1 +% ping -6 -b 70000 -s 68000 ::1 .... The IPv6 specification requires that the Jumbo Payload option must not be used in a packet that carries a fragment header. diff --git a/documentation/content/en/books/developers-handbook/ipv6/_index.po b/documentation/content/en/books/developers-handbook/ipv6/_index.po new file mode 100644 index 0000000000..d49d33461f --- /dev/null +++ b/documentation/content/en/books/developers-handbook/ipv6/_index.po @@ -0,0 +1,2133 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2023-04-20 20:56-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:1 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:15 +#, no-wrap +msgid "IPv6 Internals" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:1 +#, no-wrap +msgid "Chapter 8. IPv6 Internals" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:53 +#, no-wrap +msgid "IPv6/IPsec Implementation" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:57 +msgid "" +"This section should explain IPv6 and IPsec related implementation " +"internals. These functionalities are derived from http://www.kame.net/[KAME " +"project]" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:59 +#, no-wrap +msgid "IPv6" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:61 +#, no-wrap +msgid "Conformance" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:65 +msgid "" +"The IPv6 related functions conforms, or tries to conform to the latest set " +"of IPv6 specifications. For future reference we list some of the relevant " +"documents below (_NOTE_: this is not a complete list - this is too hard to " +"maintain...)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:67 +msgid "" +"For details please refer to specific chapter in the document, RFCs, manual " +"pages, or comments in the source code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:71 +msgid "" +"Conformance tests have been performed on the KAME STABLE kit at TAHI " +"project. Results can be viewed at http://www.tahi.org/report/KAME/[http://" +"www.tahi.org/report/KAME/]. We also attended University of New Hampshire " +"IOL tests (http://www.iol.unh.edu/[http://www.iol.unh.edu/]) in the past, " +"with our past snapshots." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:73 +msgid "RFC1639: FTP Operation Over Big Address Records (FOOBAR)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:75 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:111 +msgid "" +"RFC2428 is preferred over RFC1639. FTP clients will first try RFC2428, then " +"RFC1639 if failed." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:77 +msgid "RFC1886: DNS Extensions to support IPv6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:78 +msgid "RFC1933: Transition Mechanisms for IPv6 Hosts and Routers" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:80 +msgid "IPv4 compatible address is not supported." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:81 +msgid "automatic tunneling (described in 4.3 of this RFC) is not supported." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:82 +msgid "" +"man:gif[4] interface implements IPv[46]-over-IPv[46] tunnel in a generic " +"way, and it covers \"configured tunnel\" described in the spec. See " +"<<gif,23.5.1.5>> in this document for details." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:84 +msgid "RFC1981: Path MTU Discovery for IPv6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:85 +msgid "RFC2080: RIPng for IPv6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:87 +msgid "usr.sbin/route6d support this." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:89 +msgid "RFC2292: Advanced Sockets API for IPv6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:91 +msgid "" +"For supported library functions/kernel APIs, see [.filename]#sys/netinet6/" +"ADVAPI#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:93 +msgid "RFC2362: Protocol Independent Multicast-Sparse Mode (PIM-SM)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:95 +msgid "" +"RFC2362 defines packet formats for PIM-SM. [.filename]#draft-ietf-pim-" +"ipv6-01.txt# is written based on this." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:97 +msgid "RFC2373: IPv6 Addressing Architecture" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:99 +msgid "" +"supports node required addresses, and conforms to the scope requirement." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:101 +msgid "RFC2374: An IPv6 Aggregatable Global Unicast Address Format" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:103 +msgid "supports 64-bit length of Interface ID." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:105 +msgid "RFC2375: IPv6 Multicast Address Assignments" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:107 +msgid "Userland applications use the well-known addresses assigned in the RFC." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:109 +msgid "RFC2428: FTP Extensions for IPv6 and NATs" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:113 +msgid "RFC2460: IPv6 specification" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:114 +msgid "RFC2461: Neighbor discovery for IPv6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:116 +msgid "See <<neighbor-discovery,23.5.1.2>> in this document for details." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:118 +msgid "RFC2462: IPv6 Stateless Address Autoconfiguration" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:120 +msgid "See <<ipv6-pnp,23.5.1.4>> in this document for details." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:122 +msgid "RFC2463: ICMPv6 for IPv6 specification" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:124 +msgid "See <<icmpv6,23.5.1.9>> in this document for details." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:126 +msgid "RFC2464: Transmission of IPv6 Packets over Ethernet Networks" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:127 +msgid "RFC2465: MIB for IPv6: Textual Conventions and General Group" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:129 +msgid "" +"Necessary statistics are gathered by the kernel. Actual IPv6 MIB support is " +"provided as a patchkit for ucd-snmp." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:131 +msgid "RFC2466: MIB for IPv6: ICMPv6 group" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:133 +msgid "" +"Necessary statistics are gathered by the kernel. Actual IPv6 MIB support is " +"provided as patchkit for ucd-snmp." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:135 +msgid "RFC2467: Transmission of IPv6 Packets over FDDI Networks" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:136 +msgid "RFC2497: Transmission of IPv6 packet over ARCnet Networks" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:137 +msgid "RFC2553: Basic Socket Interface Extensions for IPv6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:139 +msgid "" +"IPv4 mapped address (3.7) and special behavior of IPv6 wildcard bind socket " +"(3.8) are supported. See <<ipv6-wildcard-socket,23.5.1.12>> in this document " +"for details." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:141 +msgid "RFC2675: IPv6 Jumbograms" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:143 +msgid "See <<ipv6-jumbo,23.5.1.7>> in this document for details." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:145 +msgid "RFC2710: Multicast Listener Discovery for IPv6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:146 +msgid "RFC2711: IPv6 router alert option" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:147 +msgid "" +"[.filename]#draft-ietf-ipngwg-router-renum-08#: Router renumbering for IPv6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:148 +msgid "" +"[.filename]#draft-ietf-ipngwg-icmp-namelookups-02#: IPv6 Name Lookups " +"Through ICMP" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:149 +msgid "" +"[.filename]#draft-ietf-ipngwg-icmp-name-lookups-03#: IPv6 Name Lookups " +"Through ICMP" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:150 +msgid "[.filename]#draft-ietf-pim-ipv6-01.txt#: PIM for IPv6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:152 +msgid "" +"man:pim6dd[8] implements dense mode. man:pim6sd[8] implements sparse mode." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:154 +msgid "" +"[.filename]#draft-itojun-ipv6-tcp-to-anycast-00#: Disconnecting TCP " +"connection toward IPv6 anycast address" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:155 +msgid "[.filename]#draft-yamamoto-wideipv6-comm-model-00#" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:157 +msgid "See <<ipv6-sas,23.5.1.6>> in this document for details." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:159 +msgid "" +"[.filename]#draft-ietf-ipngwg-scopedaddr-format-00.txt#: An Extension of " +"Format for IPv6 Scoped Addresses" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:161 +#, no-wrap +msgid "Neighbor Discovery" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:166 +msgid "" +"Neighbor Discovery is fairly stable. Currently Address Resolution, " +"Duplicated Address Detection, and Neighbor Unreachability Detection are " +"supported. In the near future we will be adding Proxy Neighbor " +"Advertisement support in the kernel and Unsolicited Neighbor Advertisement " +"transmission command as admin tool." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:171 +msgid "" +"If DAD fails, the address will be marked \"duplicated\" and message will be " +"generated to syslog (and usually to console). The \"duplicated\" mark can " +"be checked with man:ifconfig[8]. It is administrators' responsibility to " +"check for and recover from DAD failures. The behavior should be improved in " +"the near future." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:175 +msgid "" +"Some of the network driver loops multicast packets back to itself, even if " +"instructed not to do so (especially in promiscuous mode). In such cases DAD " +"may fail, because DAD engine sees inbound NS packet (actually from the node " +"itself) and considers it as a sign of duplicate. You may want to look at " +"#if condition marked \"heuristics\" in sys/netinet6/nd6_nbr.c:" +"nd6_dad_timer() as workaround (note that the code fragment in \"heuristics\" " +"section is not spec conformant)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:177 +msgid "" +"Neighbor Discovery specification (RFC2461) does not talk about neighbor " +"cache handling in the following cases:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:179 +msgid "" +"when there was no neighbor cache entry, node received unsolicited RS/NS/NA/" +"redirect packet without link-layer address" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:180 +msgid "" +"neighbor cache handling on medium without link-layer address (we need a " +"neighbor cache entry for IsRouter bit)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:183 +msgid "" +"For first case, we implemented workaround based on discussions on IETF " +"ipngwg mailing list. For more details, see the comments in the source code " +"and email thread started from (IPng 7155), dated Feb 6 1999." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:186 +msgid "" +"IPv6 on-link determination rule (RFC2461) is quite different from " +"assumptions in BSD network code. At this moment, no on-link determination " +"rule is supported where default router list is empty (RFC2461, section 5.2, " +"last sentence in 2nd paragraph - note that the spec misuse the word \"host\" " +"and \"node\" in several places in the section)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:191 +msgid "" +"To avoid possible DoS attacks and infinite loops, only 10 options on ND " +"packet is accepted now. Therefore, if you have 20 prefix options attached " +"to RA, only the first 10 prefixes will be recognized. If this troubles you, " +"please ask it on FREEBSD-CURRENT mailing list and/or modify nd6_maxndopt in " +"[.filename]#sys/netinet6/nd6.c#. If there are high demands we may provide " +"sysctl knob for the variable." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:193 +#, no-wrap +msgid "Scope Index" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:198 +msgid "" +"IPv6 uses scoped addresses. Therefore, it is very important to specify " +"scope index (interface index for link-local address, or site index for site-" +"local address) with an IPv6 address. Without scope index, scoped IPv6 " +"address is ambiguous to the kernel, and kernel will not be able to determine " +"the outbound interface for a packet." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:203 +msgid "" +"Ordinary userland applications should use advanced API (RFC2292) to specify " +"scope index, or interface index. For similar purpose, sin6_scope_id member " +"in sockaddr_in6 structure is defined in RFC2553. However, the semantics for " +"sin6_scope_id is rather vague. If you care about portability of your " +"application, we suggest you to use advanced API rather than sin6_scope_id." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:206 +msgid "" +"In the kernel, an interface index for link-local scoped address is embedded " +"into 2nd 16bit-word (3rd and 4th byte) in IPv6 address. For example, you " +"may see something like:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:210 +#, no-wrap +msgid "\tfe80:1::200:f8ff:fe01:6317\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:215 +msgid "" +"in the routing table and interface address structure (struct in6_ifaddr). " +"The address above is a link-local unicast address which belongs to a network " +"interface whose interface identifier is 1. The embedded index enables us to " +"identify IPv6 link local addresses over multiple interfaces effectively and " +"with only a little code change." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:220 +msgid "" +"Routing daemons and configuration programs, like man:route6d[8] and man:" +"ifconfig[8], will need to manipulate the \"embedded\" scope index. These " +"programs use routing sockets and ioctls (like SIOCGIFADDR_IN6) and the " +"kernel API will return IPv6 addresses with 2nd 16bit-word filled in. The " +"APIs are for manipulating kernel internal structure. Programs that use " +"these APIs have to be prepared about differences in kernels anyway." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:227 +msgid "" +"When you specify scoped address to the command line, NEVER write the " +"embedded form (such as ff02:1::1 or fe80:2::fedc). This is not supposed to " +"work. Always use standard form, like ff02::1 or fe80::fedc, with command " +"line option for specifying interface (like `ping -6 -I ne0 ff02::1`). In " +"general, if a command does not have command line option to specify outgoing " +"interface, that command is not ready to accept scoped address. This may " +"seem to be opposite from IPv6's premise to support \"dentist office\" " +"situation. We believe that specifications need some improvements for this." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:231 +msgid "" +"Some of the userland tools support extended numeric IPv6 syntax, as " +"documented in [.filename]#draft-ietf-ipngwg-scopedaddr-format-00.txt#. You " +"can specify outgoing link, by using name of the outgoing interface like " +"\"fe80::1%ne0\". This way you will be able to specify link-local scoped " +"address without much trouble." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:234 +msgid "" +"To use this extension in your program, you will need to use man:" +"getaddrinfo[3], and man:getnameinfo[3] with NI_WITHSCOPEID. The " +"implementation currently assumes 1-to-1 relationship between a link and an " +"interface, which is stronger than what specs say." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:236 +#, no-wrap +msgid "Plug and Play" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:242 +msgid "" +"Most of the IPv6 stateless address autoconfiguration is implemented in the " +"kernel. Neighbor Discovery functions are implemented in the kernel as a " +"whole. Router Advertisement (RA) input for hosts is implemented in the " +"kernel. Router Solicitation (RS) output for endhosts, RS input for routers, " +"and RA output for routers are implemented in the userland." +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:243 +#, no-wrap +msgid "Assignment of link-local, and special addresses" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:248 +msgid "" +"IPv6 link-local address is generated from IEEE802 address (Ethernet MAC " +"address). Each of interface is assigned an IPv6 link-local address " +"automatically, when the interface becomes up (IFF_UP). Also, direct route " +"for the link-local address is added to routing table." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:250 +msgid "Here is an output of netstat command:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:257 +#, no-wrap +msgid "" +"Internet6:\n" +"Destination Gateway Flags Netif Expire\n" +"fe80:1::%ed0/64 link#1 UC ed0\n" +"fe80:2::%ep0/64 link#2 UC ep0\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:262 +msgid "" +"Interfaces that has no IEEE802 address (pseudo interfaces like tunnel " +"interfaces, or ppp interfaces) will borrow IEEE802 address from other " +"interfaces, such as Ethernet interfaces, whenever possible. If there is no " +"IEEE802 hardware attached, a last resort pseudo-random value, MD5(hostname), " +"will be used as source of link-local address. If it is not suitable for " +"your usage, you will need to configure the link-local address manually." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:265 +msgid "" +"If an interface is not capable of handling IPv6 (such as lack of multicast " +"support), link-local address will not be assigned to that interface. See " +"section 2 for details." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:269 +msgid "" +"Each interface joins the solicited multicast address and the link-local all-" +"nodes multicast addresses (e.g., fe80::1:ff01:6317 and ff02::1, " +"respectively, on the link the interface is attached). In addition to a link-" +"local address, the loopback address (::1) will be assigned to the loopback " +"interface. Also, ::1/128 and ff01::/32 are automatically added to routing " +"table, and loopback interface joins node-local multicast group ff01::1." +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:270 +#, no-wrap +msgid "Stateless address autoconfiguration on Hosts" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:274 +msgid "" +"In IPv6 specification, nodes are separated into two categories: _routers_ " +"and _hosts_. Routers forward packets addressed to others, hosts does not " +"forward the packets. net.inet6.ip6.forwarding defines whether this node is " +"router or host (router if it is 1, host if it is 0)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:283 +msgid "" +"When a host hears Router Advertisement from the router, a host may " +"autoconfigure itself by stateless address autoconfiguration. This behavior " +"can be controlled by net.inet6.ip6.accept_rtadv (host autoconfigures itself " +"if it is set to 1). By autoconfiguration, network address prefix for the " +"receiving interface (usually global address prefix) is added. Default route " +"is also configured. Routers periodically generate Router Advertisement " +"packets. To request an adjacent router to generate RA packet, a host can " +"transmit Router Solicitation. To generate a RS packet at any time, use the " +"_rtsol_ command. man:rtsold[8] daemon is also available. man:rtsold[8] " +"generates Router Solicitation whenever necessary, and it works great for " +"nomadic usage (notebooks/laptops). If one wishes to ignore Router " +"Advertisements, use sysctl to set net.inet6.ip6.accept_rtadv to 0." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:285 +msgid "" +"To generate Router Advertisement from a router, use the man:rtadvd[8] daemon." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:287 +msgid "" +"Note that, IPv6 specification assumes the following items, and nonconforming " +"cases are left unspecified:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:289 +msgid "Only hosts will listen to router advertisements" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:290 +msgid "Hosts have single network interface (except loopback)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:293 +msgid "" +"Therefore, this is unwise to enable net.inet6.ip6.accept_rtadv on routers, " +"or multi-interface host. A misconfigured node can behave strange " +"(nonconforming configuration allowed for those who would like to do some " +"experiments)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:295 +msgid "To summarize the sysctl knob:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:309 +#, no-wrap +msgid "" +"\taccept_rtadv\tforwarding\trole of the node\n" +"\t---\t\t---\t\t---\n" +"\t0\t\t0\t\thost (to be manually configured)\n" +"\t0\t\t1\t\trouter\n" +"\t1\t\t0\t\tautoconfigured host\n" +"\t\t\t\t\t(spec assumes that host has single\n" +"\t\t\t\t\tinterface only, autoconfigured host\n" +"\t\t\t\t\twith multiple interface is\n" +"\t\t\t\t\tout-of-scope)\n" +"\t1\t\t1\t\tinvalid, or experimental\n" +"\t\t\t\t\t(out-of-scope of spec)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:314 +msgid "" +"RFC2462 has validation rule against incoming RA prefix information option, " +"in 5.5.3 (e). This is to protect hosts from malicious (or misconfigured) " +"routers that advertise very short prefix lifetime. There was an update from " +"Jim Bound to ipngwg mailing list (look for \"(ipng 6712)\" in the archive) " +"and it is implemented Jim's update." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:316 +msgid "" +"See <<neighbor-discovery,23.5.1.2>> in the document for relationship between " +"DAD and autoconfiguration." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:318 +#, no-wrap +msgid "Generic Tunnel Interface" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:322 +msgid "" +"GIF (Generic InterFace) is a pseudo interface for configured tunnel. " +"Details are described in man:gif[4]. Currently" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:324 +msgid "v6 in v6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:325 +msgid "v6 in v4" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:326 +msgid "v4 in v6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:327 +msgid "v4 in v4" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:332 +msgid "" +"are available. Use man:gifconfig[8] to assign physical (outer) source and " +"destination address to gif interfaces. Configuration that uses same address " +"family for inner and outer IP header (v4 in v4, or v6 in v6) is dangerous. " +"It is very easy to configure interfaces and routing tables to perform " +"infinite level of tunneling. _Please be warned_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:335 +msgid "" +"gif can be configured to be ECN-friendly. See <<ipsec-ecn,23.5.4.5>> for " +"ECN-friendliness of tunnels, and man:gif[4] for how to configure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:338 +msgid "" +"If you would like to configure an IPv4-in-IPv6 tunnel with gif interface, " +"read man:gif[4] carefully. You will need to remove IPv6 link-local address " +"automatically assigned to the gif interface." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:340 +#, no-wrap +msgid "Source Address Selection" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:344 +msgid "" +"Current source selection rule is scope oriented (there are some exceptions - " +"see below). For a given destination, a source IPv6 address is selected by " +"the following rule:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:346 +msgid "" +"If the source address is explicitly specified by the user (e.g., via the " +"advanced API), the specified address is used." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:347 +msgid "" +"If there is an address assigned to the outgoing interface (which is usually " +"determined by looking up the routing table) that has the same scope as the " +"destination address, the address is used." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:349 +msgid "This is the most typical case." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:350 +msgid "" +"If there is no address that satisfies the above condition, choose a global " +"address assigned to one of the interfaces on the sending node." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:351 +msgid "" +"If there is no address that satisfies the above condition, and destination " +"address is site local scope, choose a site local address assigned to one of " +"the interfaces on the sending node." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:352 +msgid "" +"If there is no address that satisfies the above condition, choose the " +"address associated with the routing table entry for the destination. This is " +"the last resort, which may cause scope violation." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:357 +msgid "" +"For instance, ::1 is selected for ff01::1, fe80:1::200:f8ff:fe01:6317 for " +"fe80:1::2a0:24ff:feab:839b (note that embedded interface index - described " +"in <<ipv6-scope-index,23.5.1.3>> - helps us choose the right source " +"address. Those embedded indices will not be on the wire). If the outgoing " +"interface has multiple address for the scope, a source is selected longest " +"match basis (rule 3). Suppose 2001:0DB8:808:1:200:f8ff:fe01:6317 and " +"2001:0DB8:9:124:200:f8ff:fe01:6317 are given to the outgoing interface. " +"2001:0DB8:808:1:200:f8ff:fe01:6317 is chosen as the source for the " +"destination 2001:0DB8:800::1." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:364 +msgid "" +"Note that the above rule is not documented in the IPv6 spec. It is " +"considered \"up to implementation\" item. There are some cases where we do " +"not use the above rule. One example is connected TCP session, and we use " +"the address kept in tcb as the source. Another example is source address " +"for Neighbor Advertisement. Under the spec (RFC2461 7.2.2) NA's source " +"should be the target address of the corresponding NS's target. In this case " +"we follow the spec rather than the above longest-match rule." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:370 +msgid "" +"For new connections (when rule 1 does not apply), deprecated addresses " +"(addresses with preferred lifetime = 0) will not be chosen as source address " +"if other choices are available. If no other choices are available, " +"deprecated address will be used as a last resort. If there are multiple " +"choice of deprecated addresses, the above scope rule will be used to choose " +"from those deprecated addresses. If you would like to prohibit the use of " +"deprecated address for some reason, configure net.inet6.ip6.use_deprecated " +"to 0. The issue related to deprecated address is described in RFC2462 5.5.4 " +"(NOTE: there is some debate underway in IETF ipngwg on how to use " +"\"deprecated\" address)." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:372 +#, no-wrap +msgid "Jumbo Payload" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:376 +msgid "" +"The Jumbo Payload hop-by-hop option is implemented and can be used to send " +"IPv6 packets with payloads longer than 65,535 octets. But currently no " +"physical interface whose MTU is more than 65,535 is supported, so such " +"payloads can be seen only on the loopback interface (i.e., lo0)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:378 +msgid "" +"If you want to try jumbo payloads, you first have to reconfigure the kernel " +"so that the MTU of the loopback interface is more than 65,535 bytes; add the " +"following to the kernel configuration file:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:380 +msgid "`options \"LARGE_LOMTU\" #To test jumbo payload`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:382 +msgid "and recompile the new kernel." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:386 +msgid "" +"Then you can test jumbo payloads by the man:ping[8] command with -6, -b and -" +"s options. The -b option must be specified to enlarge the size of the " +"socket buffer and the -s option specifies the length of the packet, which " +"should be more than 65,535. For example, type as follows:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:390 +#, no-wrap +msgid "% ping -6 -b 70000 -s 68000 ::1\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:395 +msgid "" +"The IPv6 specification requires that the Jumbo Payload option must not be " +"used in a packet that carries a fragment header. If this condition is " +"broken, an ICMPv6 Parameter Problem message must be sent to the sender. " +"specification is followed, but you cannot usually see an ICMPv6 error caused " +"by this requirement." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:399 +msgid "" +"When an IPv6 packet is received, the frame length is checked and compared to " +"the length specified in the payload length field of the IPv6 header or in " +"the value of the Jumbo Payload option, if any. If the former is shorter " +"than the latter, the packet is discarded and statistics are incremented. " +"You can see the statistics as output of man:netstat[8] command with `-s -p " +"ip6' option:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:406 +#, no-wrap +msgid "" +"% netstat -s -p ip6\n" +"\t ip6:\n" +"\t\t(snip)\n" +"\t\t1 with data size < data length\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:410 +msgid "" +"So, kernel does not send an ICMPv6 error unless the erroneous packet is an " +"actual Jumbo Payload, that is, its packet size is more than 65,535 bytes. " +"As described above, currently no physical interface with such a huge MTU is " +"supported, so it rarely returns an ICMPv6 error." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:413 +msgid "" +"TCP/UDP over jumbogram is not supported at this moment. This is because we " +"have no medium (other than loopback) to test this. Contact us if you need " +"this." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:416 +msgid "" +"IPsec does not work on jumbograms. This is due to some specification twists " +"in supporting AH with jumbograms (AH header size influences payload length, " +"and this makes it real hard to authenticate inbound packet with jumbo " +"payload option as well as AH)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:420 +msgid "" +"There are fundamental issues in *BSD support for jumbograms. We would like " +"to address those, but we need more time to finalize these. To name a few:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:424 +msgid "" +"mbuf pkthdr.len field is typed as \"int\" in 4.4BSD, so it will not hold " +"jumbogram with len > 2G on 32bit architecture CPUs. If we would like to " +"support jumbogram properly, the field must be expanded to hold 4G + IPv6 " +"header + link-layer header. Therefore, it must be expanded to at least " +"int64_t (u_int32_t is NOT enough)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:426 +msgid "" +"We mistakingly use \"int\" to hold packet length in many places. We need to " +"convert them into larger integral type. It needs a great care, as we may " +"experience overflow during packet length computation." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:427 +msgid "" +"We mistakingly check for ip6_plen field of IPv6 header for packet payload " +"length in various places. We should be checking mbuf pkthdr.len instead. " +"ip6_input() will perform sanity check on jumbo payload option on input, and " +"we can safely use mbuf pkthdr.len afterwards." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:428 +msgid "TCP code needs a careful update in bunch of places, of course." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:429 +#, no-wrap +msgid "Loop Prevention in Header Processing" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:440 +msgid "" +"IPv6 specification allows arbitrary number of extension headers to be placed " +"onto packets. If we implement IPv6 packet processing code in the way BSD " +"IPv4 code is implemented, kernel stack may overflow due to long function " +"call chain. sys/netinet6 code is carefully designed to avoid kernel stack " +"overflow, so sys/netinet6 code defines its own protocol switch structure, as " +"\"struct ip6protosw\" (see [.filename]#netinet6/ip6protosw.h#). There is no " +"such update to IPv4 part (sys/netinet) for compatibility, but small change " +"is added to its pr_input() prototype. So \"struct ipprotosw\" is also " +"defined. As a result, if you receive IPsec-over-IPv4 packet with massive " +"number of IPsec headers, kernel stack may blow up. IPsec-over-IPv6 is " +"okay. (Of-course, for those all IPsec headers to be processed, each such " +"IPsec header must pass each IPsec check. So an anonymous attacker will not " +"be able to do such an attack.)" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:442 +#, no-wrap +msgid "ICMPv6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:446 +msgid "" +"After RFC2463 was published, IETF ipngwg has decided to disallow ICMPv6 " +"error packet against ICMPv6 redirect, to prevent ICMPv6 storm on a network " +"medium. This is already implemented into the kernel." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:447 +#, no-wrap +msgid "Applications" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:450 +msgid "" +"For userland programming, we support IPv6 socket API as specified in " +"RFC2553, RFC2292 and upcoming Internet drafts." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:455 +msgid "" +"TCP/UDP over IPv6 is available and quite stable. You can enjoy man:" +"telnet[1], man:ftp[1], man:rlogin[1], man:rsh[1], man:ssh[1], etc. These " +"applications are protocol independent. That is, they automatically chooses " +"IPv4 or IPv6 according to DNS." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:456 +#, no-wrap +msgid "Kernel Internals" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:459 +msgid "" +"While ip_forward() calls ip_output(), ip6_forward() directly calls " +"if_output() since routers must not divide IPv6 packets into fragments." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:463 +msgid "" +"ICMPv6 should contain the original packet as long as possible up to 1280. " +"UDP6/IP6 port unreach, for instance, should contain all extension headers " +"and the *unchanged* UDP6 and IP6 headers. So, all IP6 functions except TCP " +"never convert network byte order into host byte order, to save the original " +"packet." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:467 +msgid "" +"tcp_input(), udp6_input() and icmp6_input() can not assume that IP6 header " +"is preceding the transport headers due to extension headers. So, " +"in6_cksum() was implemented to handle packets whose IP6 header and transport " +"header is not continuous. TCP/IP6 nor UDP6/IP6 header structures do not " +"exist for checksum calculation." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:470 +msgid "" +"To process IP6 header, extension headers and transport headers easily, " +"network drivers are now required to store packets in one internal mbuf or " +"one or more external mbufs. A typical old driver prepares two internal " +"mbufs for 96 - 204 bytes data, however, now such packet data is stored in " +"one external mbuf." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:474 +msgid "" +"`netstat -s -p ip6` tells you whether or not your driver conforms such " +"requirement. In the following example, \"cce0\" violates the requirement. " +"(For more information, refer to Section 2.)" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:484 +#, no-wrap +msgid "" +"Mbuf statistics:\n" +" 317 one mbuf\n" +" two or more mbuf::\n" +" lo0 = 8\n" +"\t\t\tcce0 = 10\n" +" 3282 one ext mbuf\n" +" 0 two or more ext mbuf\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:489 +msgid "" +"Each input function calls IP6_EXTHDR_CHECK in the beginning to check if the " +"region between IP6 and its header is continuous. IP6_EXTHDR_CHECK calls " +"m_pullup() only if the mbuf has M_LOOP flag, that is, the packet comes from " +"the loopback interface. m_pullup() is never called for packets coming from " +"physical network interfaces." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:491 +msgid "Both IP and IP6 reassemble functions never call m_pullup()." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:493 +#, no-wrap +msgid "IPv4 Mapped Address and IPv6 Wildcard Socket" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:497 +msgid "" +"RFC2553 describes IPv4 mapped address (3.7) and special behavior of IPv6 " +"wildcard bind socket (3.8). The spec allows you to:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:499 +msgid "Accept IPv4 connections by AF_INET6 wildcard bind socket." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:500 +msgid "" +"Transmit IPv4 packet over AF_INET6 socket by using special form of the " +"address like ::ffff:10.1.1.1." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:503 +msgid "" +"but the spec itself is very complicated and does not specify how the socket " +"layer should behave. Here we call the former one \"listening side\" and the " +"latter one \"initiating side\", for reference purposes." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:505 +msgid "" +"You can perform wildcard bind on both of the address families, on the same " +"port." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:507 +msgid "The following table show the behavior of FreeBSD 4.x." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:516 +#, no-wrap +msgid "" +"listening side initiating side\n" +" (AF_INET6 wildcard (connection to ::ffff:10.1.1.1)\n" +" socket gets IPv4 conn.)\n" +" --- ---\n" +"FreeBSD 4.x configurable supported\n" +" default: enabled\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:519 +msgid "" +"The following sections will give you more details, and how you can configure " +"the behavior." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:521 +msgid "Comments on listening side:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:528 +msgid "" +"It looks that RFC2553 talks too little on wildcard bind issue, especially on " +"the port space issue, failure mode and relationship between AF_INET/INET6 " +"wildcard bind. There can be several separate interpretation for this RFC " +"which conform to it but behaves differently. So, to implement portable " +"application you should assume nothing about the behavior in the kernel. " +"Using man:getaddrinfo[3] is the safest way. Port number space and wildcard " +"bind issues were discussed in detail on ipv6imp mailing list, in mid March " +"1999 and it looks that there is no concrete consensus (means, up to " +"implementers). You may want to check the mailing list archives." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:530 +msgid "" +"If a server application would like to accept IPv4 and IPv6 connections, " +"there will be two alternatives." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:535 +msgid "" +"One is using AF_INET and AF_INET6 socket (you will need two sockets). Use " +"man:getaddrinfo[3] with AI_PASSIVE into ai_flags, and man:socket[2] and man:" +"bind[2] to all the addresses returned. By opening multiple sockets, you can " +"accept connections onto the socket with proper address family. IPv4 " +"connections will be accepted by AF_INET socket, and IPv6 connections will be " +"accepted by AF_INET6 socket." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:541 +msgid "" +"Another way is using one AF_INET6 wildcard bind socket. Use man:" +"getaddrinfo[3] with AI_PASSIVE into ai_flags and with AF_INET6 into " +"ai_family, and set the 1st argument hostname to NULL. And man:socket[2] and " +"man:bind[2] to the address returned. (should be IPv6 unspecified addr). " +"You can accept either of IPv4 and IPv6 packet via this one socket." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:545 +msgid "" +"To support only IPv6 traffic on AF_INET6 wildcard binded socket portably, " +"always check the peer address when a connection is made toward AF_INET6 " +"listening socket. If the address is IPv4 mapped address, you may want to " +"reject the connection. You can check the condition by using " +"IN6_IS_ADDR_V4MAPPED() macro." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:547 +msgid "" +"To resolve this issue more easily, there is system dependent man:" +"setsockopt[2] option, IPV6_BINDV6ONLY, used like below." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:551 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:598 +#, no-wrap +msgid "\tint on;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:554 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:601 +#, no-wrap +msgid "" +"\tsetsockopt(s, IPPROTO_IPV6, IPV6_BINDV6ONLY,\n" +"\t\t (char *)&on, sizeof (on)) < 0));\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:557 +msgid "When this call succeed, then this socket only receive IPv6 packets." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:559 +msgid "Comments on initiating side:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:561 +msgid "" +"Advise to application implementers: to implement a portable IPv6 application " +"(which works on multiple IPv6 kernels), we believe that the following is the " +"key to the success:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:563 +msgid "NEVER hardcode AF_INET nor AF_INET6." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:564 +msgid "" +"Use man:getaddrinfo[3] and man:getnameinfo[3] throughout the system. Never " +"use gethostby*(), getaddrby*(), inet_*() or getipnodeby*(). (To update " +"existing applications to be IPv6 aware easily, sometime getipnodeby*() will " +"be useful. But if possible, try to rewrite the code to use man:" +"getaddrinfo[3] and man:getnameinfo[3].)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:565 +msgid "" +"If you would like to connect to destination, use man:getaddrinfo[3] and try " +"all the destination returned, like man:telnet[1] does." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:566 +msgid "" +"Some of the IPv6 stack is shipped with buggy man:getaddrinfo[3]. Ship a " +"minimal working version with your application and use that as last resort." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:572 +msgid "" +"If you would like to use AF_INET6 socket for both IPv4 and IPv6 outgoing " +"connection, you will need to use man:getipnodebyname[3]. When you would " +"like to update your existing application to be IPv6 aware with minimal " +"effort, this approach might be chosen. But please note that it is a " +"temporal solution, because man:getipnodebyname[3] itself is not recommended " +"as it does not handle scoped IPv6 addresses at all. For IPv6 name " +"resolution, man:getaddrinfo[3] is the preferred API. So you should rewrite " +"your application to use man:getaddrinfo[3], when you get the time to do it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:576 +msgid "" +"When writing applications that make outgoing connections, story goes much " +"simpler if you treat AF_INET and AF_INET6 as totally separate address " +"family. {set,get}sockopt issue goes simpler, DNS issue will be made " +"simpler. We do not recommend you to rely upon IPv4 mapped address." +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:577 +#, no-wrap +msgid "unified tcp and inpcb code" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:581 +msgid "" +"FreeBSD 4.x uses shared tcp code between IPv4 and IPv6 (from sys/netinet/" +"tcp*) and separate udp4/6 code. It uses unified inpcb structure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:584 +msgid "" +"The platform can be configured to support IPv4 mapped address. Kernel " +"configuration is summarized as follows:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:586 +msgid "" +"By default, AF_INET6 socket will grab IPv4 connections in certain condition, " +"and can initiate connection to IPv4 destination embedded in IPv4 mapped IPv6 " +"address." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:587 +msgid "You can disable it on entire system with sysctl like below." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:589 +msgid "`sysctl net.inet6.ip6.mapped_addr=0`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:591 +msgid "====== Listening Side" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:594 +msgid "" +"Each socket can be configured to support special AF_INET6 wildcard bind " +"(enabled by default). You can disable it on each socket basis with man:" +"setsockopt[2] like below." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:604 +msgid "" +"Wildcard AF_INET6 socket grabs IPv4 connection if and only if the following " +"conditions are satisfied:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:606 +msgid "there is no AF_INET socket that matches the IPv4 connection" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:607 +msgid "" +"the AF_INET6 socket is configured to accept IPv4 traffic, i.e., " +"getsockopt(IPV6_BINDV6ONLY) returns 0." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:609 +msgid "There is no problem with open/close ordering." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:611 +msgid "====== Initiating Side" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:613 +msgid "" +"FreeBSD 4.x supports outgoing connection to IPv4 mapped address (::" +"ffff:10.1.1.1), if the node is configured to support IPv4 mapped address." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:614 +#, no-wrap +msgid "sockaddr_storage" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:620 +msgid "" +"When RFC2553 was about to be finalized, there was discussion on how struct " +"sockaddr_storage members are named. One proposal is to prepend \"__\" to " +"the members (like \"__ss_len\") as they should not be touched. The other " +"proposal was not to prepend it (like \"ss_len\") as we need to touch those " +"members directly. There was no clear consensus on it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:622 +msgid "As a result, RFC2553 defines struct sockaddr_storage as follows:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:630 +#, no-wrap +msgid "" +"\tstruct sockaddr_storage {\n" +"\t\tu_char\t__ss_len;\t/* address length */\n" +"\t\tu_char\t__ss_family;\t/* address family */\n" +"\t\t/* and bunch of padding */\n" +"\t};\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:633 +msgid "On the contrary, XNET draft defines as follows:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:641 +#, no-wrap +msgid "" +"\tstruct sockaddr_storage {\n" +"\t\tu_char\tss_len;\t\t/* address length */\n" +"\t\tu_char\tss_family;\t/* address family */\n" +"\t\t/* and bunch of padding */\n" +"\t};\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:644 +msgid "" +"In December 1999, it was agreed that RFC2553bis should pick the latter " +"(XNET) definition." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:646 +msgid "" +"Current implementation conforms to XNET definition, based on RFC2553bis " +"discussion." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:649 +msgid "" +"If you look at multiple IPv6 implementations, you will be able to see both " +"definitions. As an userland programmer, the most portable way of dealing " +"with it is to:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:651 +msgid "" +"ensure ss_family and/or ss_len are available on the platform, by using GNU " +"autoconf," +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:652 +msgid "" +"have -Dss_family=__ss_family to unify all occurrences (including header " +"file) into __ss_family, or" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:653 +msgid "never touch __ss_family. cast to sockaddr * and use sa_family like:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:658 +#, no-wrap +msgid "" +"\tstruct sockaddr_storage ss;\n" +"\tfamily = ((struct sockaddr *)&ss)->sa_family\n" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:660 +#, no-wrap +msgid "Network Drivers" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:663 +msgid "" +"Now following two items are required to be supported by standard drivers:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:665 +msgid "" +"mbuf clustering requirement. In this stable release, we changed MINCLSIZE " +"into MHLEN+1 for all the operating systems in order to make all the drivers " +"behave as we expect." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:666 +msgid "" +"multicast. If man:ifmcstat[8] yields no multicast group for a interface, " +"that interface has to be patched." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:669 +msgid "" +"If any of the drivers do not support the requirements, then the drivers " +"cannot be used for IPv6 and/or IPsec communication. If you find any problem " +"with your card using IPv6/IPsec, then, please report it to the {freebsd-" +"bugs}." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:672 +msgid "" +"(NOTE: In the past we required all PCMCIA drivers to have a call to " +"in6_ifattach(). We have no such requirement any more)" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:673 +#, no-wrap +msgid "Translator" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:676 +msgid "We categorize IPv4/IPv6 translator into 4 types:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:678 +msgid "" +"_Translator A_ --- It is used in the early stage of transition to make it " +"possible to establish a connection from an IPv6 host in an IPv6 island to an " +"IPv4 host in the IPv4 ocean." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:679 +msgid "" +"_Translator B_ --- It is used in the early stage of transition to make it " +"possible to establish a connection from an IPv4 host in the IPv4 ocean to an " +"IPv6 host in an IPv6 island." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:680 +msgid "" +"_Translator C_ --- It is used in the late stage of transition to make it " +"possible to establish a connection from an IPv4 host in an IPv4 island to an " +"IPv6 host in the IPv6 ocean." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:681 +msgid "" +"_Translator D_ --- It is used in the late stage of transition to make it " +"possible to establish a connection from an IPv6 host in the IPv6 ocean to an " +"IPv4 host in an IPv4 island." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:683 +#, no-wrap +msgid "IPsec" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:686 +msgid "IPsec is mainly organized by three components." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:688 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:691 +#, no-wrap +msgid "Policy Management" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:689 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:701 +#, no-wrap +msgid "Key Management" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:690 +msgid "AH and ESP handling" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:698 +msgid "" +"The kernel implements experimental policy management code. There are two " +"way to manage security policy. One is to configure per-socket policy using " +"man:setsockopt[2]. In this cases, policy configuration is described in man:" +"ipsec_set_policy[3]. The other is to configure kernel packet filter-based " +"policy using PF_KEY interface, via man:setkey[8]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:700 +msgid "" +"The policy entry is not re-ordered with its indexes, so the order of entry " +"when you add is very significant." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:705 +msgid "" +"The key management code implemented in this kit (sys/netkey) is a home-brew " +"PFKEY v2 implementation. This conforms to RFC2367." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:709 +msgid "" +"The home-brew IKE daemon, \"racoon\" is included in the kit (kame/kame/" +"racoon). Basically you will need to run racoon as daemon, then set up a " +"policy to require keys (like `ping -P 'out ipsec esp/transport//use'`). The " +"kernel will contact racoon daemon as necessary to exchange keys." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:710 +#, no-wrap +msgid "AH and ESP Handling" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:718 +msgid "" +"IPsec module is implemented as \"hooks\" to the standard IPv4/IPv6 " +"processing. When sending a packet, ip{,6}_output() checks if ESP/AH " +"processing is required by checking if a matching SPD (Security Policy " +"Database) is found. If ESP/AH is needed, {esp,ah}{4,6}_output() will be " +"called and mbuf will be updated accordingly. When a packet is received, " +"{esp,ah}4_input() will be called based on protocol number, i.e., " +"(*inetsw[proto])(). {esp,ah}4_input() will decrypt/check authenticity of " +"the packet, and strips off daisy-chained header and padding for ESP/AH. It " +"is safe to strip off the ESP/AH header on packet reception, since we will " +"never use the received packet in \"as is\" form." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:721 +msgid "" +"By using ESP/AH, TCP4/6 effective data segment size will be affected by " +"extra daisy-chained headers inserted by ESP/AH. Our code takes care of the " +"case." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:725 +msgid "" +"Basic crypto functions can be found in directory \"sys/crypto\". ESP/AH " +"transform are listed in {esp,ah}_core.c with wrapper functions. If you wish " +"to add some algorithm, add wrapper function in {esp,ah}_core.c, and add your " +"crypto algorithm code into sys/crypto." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:727 +msgid "" +"Tunnel mode is partially supported in this release, with the following " +"restrictions:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:729 +msgid "" +"IPsec tunnel is not combined with GIF generic tunneling interface. It needs " +"a great care because we may create an infinite loop between ip_output() and " +"tunnelifp->if_output(). Opinion varies if it is better to unify them, or not." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:730 +msgid "" +"MTU and Don't Fragment bit (IPv4) considerations need more checking, but " +"basically works fine." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:731 +msgid "" +"Authentication model for AH tunnel must be revisited. We will need to " +"improve the policy management engine, eventually." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:732 +#, no-wrap +msgid "Conformance to RFCs and IDs" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:735 +msgid "" +"The IPsec code in the kernel conforms (or, tries to conform) to the " +"following standards:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:737 +msgid "\"old IPsec\" specification documented in [.filename]#rfc182[5-9].txt#" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:740 +msgid "" +"\"new IPsec\" specification documented in [.filename]#rfc240[1-6].txt#, [." +"filename]#rfc241[01].txt#, [.filename]#rfc2451.txt# and [.filename]#draft-" +"mcdonald-simple-ipsec-api-01.txt# (draft expired, but you can take from link:" +"ftp://ftp.kame.net/pub/internet-drafts/[ ftp://ftp.kame.net/pub/internet-" +"drafts/]). (NOTE: IKE specifications, [.filename]#rfc241[7-9].txt# are " +"implemented in userland, as \"racoon\" IKE daemon)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:742 +msgid "Currently supported algorithms are:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:744 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:781 +msgid "old IPsec AH" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:746 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:759 +msgid "null crypto checksum (no document, just for debugging)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:747 +msgid "keyed MD5 with 128bit crypto checksum ([.filename]#rfc1828.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:748 +msgid "keyed SHA1 with 128bit crypto checksum (no document)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:749 +msgid "HMAC MD5 with 128bit crypto checksum ([.filename]#rfc2085.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:750 +msgid "HMAC SHA1 with 128bit crypto checksum (no document)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:752 +msgid "old IPsec ESP" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:754 +msgid "null encryption (no document, similar to [.filename]#rfc2410.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:755 +msgid "DES-CBC mode ([.filename]#rfc1829.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:757 +msgid "new IPsec AH" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:760 +msgid "keyed MD5 with 96bit crypto checksum (no document)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:761 +msgid "keyed SHA1 with 96bit crypto checksum (no document)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:762 +msgid "HMAC MD5 with 96bit crypto checksum ([.filename]#rfc2403.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:763 +msgid "HMAC SHA1 with 96bit crypto checksum ([.filename]#rfc2404.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:765 +msgid "new IPsec ESP" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:767 +msgid "null encryption ([.filename]#rfc2410.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:768 +msgid "" +"DES-CBC with derived IV ([.filename]#draft-ietf-ipsec-ciph-des-derived-01." +"txt#, draft expired)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:769 +msgid "DES-CBC with explicit IV ([.filename]#rfc2405.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:770 +msgid "3DES-CBC with explicit IV ([.filename]#rfc2451.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:771 +msgid "BLOWFISH CBC ([.filename]#rfc2451.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:772 +msgid "CAST128 CBC ([.filename]#rfc2451.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:773 +msgid "RC5 CBC ([.filename]#rfc2451.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:774 +msgid "each of the above can be combined with:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:776 +msgid "ESP authentication with HMAC-MD5(96bit)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:777 +msgid "ESP authentication with HMAC-SHA1(96bit)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:779 +msgid "The following algorithms are NOT supported:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:783 +msgid "" +"HMAC MD5 with 128bit crypto checksum + 64bit replay prevention ([." +"filename]#rfc2085.txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:784 +msgid "" +"keyed SHA1 with 160bit crypto checksum + 32bit padding ([.filename]#rfc1852." +"txt#)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:787 +msgid "" +"IPsec (in kernel) and IKE (in userland as \"racoon\") has been tested at " +"several interoperability test events, and it is known to interoperate with " +"many other implementations well. Also, current IPsec implementation as " +"quite wide coverage for IPsec crypto algorithms documented in RFC (we cover " +"algorithms without intellectual property issues only)." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:789 +#, no-wrap +msgid "ECN Consideration on IPsec Tunnels" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:792 +msgid "" +"ECN-friendly IPsec tunnel is supported as described in [.filename]#draft-" +"ipsec-ecn-00.txt#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:797 +msgid "" +"Normal IPsec tunnel is described in RFC2401. On encapsulation, IPv4 TOS " +"field (or, IPv6 traffic class field) will be copied from inner IP header to " +"outer IP header. On decapsulation outer IP header will be simply dropped. " +"The decapsulation rule is not compatible with ECN, since ECN bit on the " +"outer IP TOS/traffic class field will be lost." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:800 +msgid "" +"To make IPsec tunnel ECN-friendly, we should modify encapsulation and " +"decapsulation procedure. This is described in http://www.aciri.org/floyd/" +"papers/draft-ipsec-ecn-00.txt[ http://www.aciri.org/floyd/papers/draft-ipsec-" +"ecn-00.txt], chapter 3." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:802 +msgid "" +"IPsec tunnel implementation can give you three behaviors, by setting net." +"inet.ipsec.ecn (or net.inet6.ipsec6.ecn) to some value:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:804 +msgid "RFC2401: no consideration for ECN (sysctl value -1)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:805 +msgid "ECN forbidden (sysctl value 0)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:806 +msgid "ECN allowed (sysctl value 1)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:808 +msgid "" +"Note that the behavior is configurable in per-node manner, not per-SA manner " +"(draft-ipsec-ecn-00 wants per-SA configuration, but it looks too much for " +"me)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:810 +msgid "" +"The behavior is summarized as follows (see source code for more detail):" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:817 +#, no-wrap +msgid "" +"encapsulate decapsulate\n" +" --- ---\n" +"RFC2401 copy all TOS bits drop TOS bits on outer\n" +" from inner to outer. (use inner TOS bits as is)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:821 +#, no-wrap +msgid "" +"ECN forbidden copy TOS bits except for ECN drop TOS bits on outer\n" +" (masked with 0xfc) from inner (use inner TOS bits as is)\n" +" to outer. set ECN bits to 0.\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:826 +#, no-wrap +msgid "" +"ECN allowed copy TOS bits except for ECN use inner TOS bits with some\n" +" CE (masked with 0xfe) from change. if outer ECN CE bit\n" +" inner to outer. is 1, enable ECN CE bit on\n" +" set ECN CE bit to 0. the inner.\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:829 +msgid "General strategy for configuration is as follows:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:831 +msgid "" +"if both IPsec tunnel endpoint are capable of ECN-friendly behavior, you " +"should better configure both end to \"ECN allowed\" (sysctl value 1)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:832 +msgid "" +"if the other end is very strict about TOS bit, use \"RFC2401\" (sysctl value " +"-1)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:833 +msgid "in other cases, use \"ECN forbidden\" (sysctl value 0)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:835 +msgid "The default behavior is \"ECN forbidden\" (sysctl value 0)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:837 +msgid "For more information, please refer to:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:839 +msgid "" +"http://www.aciri.org/floyd/papers/draft-ipsec-ecn-00.txt[ http://www.aciri." +"org/floyd/papers/draft-ipsec-ecn-00.txt], RFC2481 (Explicit Congestion " +"Notification), src/sys/netinet6/{ah,esp}_input.c" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:841 +msgid "" +"(Thanks goes to Kenjiro Cho mailto:kjc@csl.sony.co.jp[kjc@csl.sony.co.jp] " +"for detailed analysis)" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:842 +#, no-wrap +msgid "Interoperability" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:846 +msgid "" +"Here are (some of) platforms that KAME code have tested IPsec/IKE " +"interoperability in the past. Note that both ends may have modified their " +"implementation, so use the following list just for reference purposes." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/ipv6/_index.adoc:847 +msgid "" +"Altiga, Ashley-laurent (vpcom.com), Data Fellows (F-Secure), Ericsson ACC, " +"FreeS/WAN, HITACHI, IBM AIX(R), IIJ, Intel, Microsoft(R) Windows NT(R), NIST " +"(linux IPsec + plutoplus), Netscreen, OpenBSD, RedCreek, Routerware, SSH, " +"Secure Computing, Soliton, Toshiba, VPNet, Yamaha RT100i" +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc b/documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc index 17865d2606..1d8bee3169 100644 --- a/documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc +++ b/documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc @@ -7,7 +7,7 @@ description: Building and Installing a FreeBSD Kernel tags: ["building", "installing", "kernel", "FreeBSD"] showBookMenu: true weight: 12 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/kernelbuild/" --- [[kernelbuild]] @@ -52,11 +52,11 @@ Being a kernel developer requires understanding of the kernel build process. To debug the FreeBSD kernel it is required to be able to build one. There are two known ways to do so: -The supported procedure to build and install a kernel is documented in the extref:{handbook}[Building and Installing a Custom Kernel, kernelconfig-building] chapter of the FreeBSD Handbook. +The supported procedure to build and install a kernel is documented in the extref:{handbook}kernelconfig/[Building and Installing a Custom Kernel, kernelconfig-building] chapter of the FreeBSD Handbook. [NOTE] ==== -It is supposed that the reader of this chapter is familiar with the information described in the extref:{handbook}[Building and Installing a Custom Kernel, kernelconfig-building] chapter of the FreeBSD Handbook. +It is supposed that the reader of this chapter is familiar with the information described in the extref:{handbook}kernelconfig/[Building and Installing a Custom Kernel, kernelconfig-building] chapter of the FreeBSD Handbook. If this is not the case, please read through the above mentioned chapter to understand how the build process works. ==== diff --git a/documentation/content/en/books/developers-handbook/kernelbuild/_index.po b/documentation/content/en/books/developers-handbook/kernelbuild/_index.po new file mode 100644 index 0000000000..96a084e16f --- /dev/null +++ b/documentation/content/en/books/developers-handbook/kernelbuild/_index.po @@ -0,0 +1,119 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2023-07-15 16:42-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:1 +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:14 +#, no-wrap +msgid "Building and Installing a FreeBSD Kernel" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:1 +#, no-wrap +msgid "Chapter 9. Building and Installing a FreeBSD Kernel" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:54 +msgid "" +"Being a kernel developer requires understanding of the kernel build " +"process. To debug the FreeBSD kernel it is required to be able to build " +"one. There are two known ways to do so:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:56 +msgid "" +"The supported procedure to build and install a kernel is documented in the " +"extref:{handbook}kernelconfig/[Building and Installing a Custom Kernel, " +"kernelconfig-building] chapter of the FreeBSD Handbook." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:61 +msgid "" +"It is supposed that the reader of this chapter is familiar with the " +"information described in the extref:{handbook}kernelconfig/[Building and " +"Installing a Custom Kernel, kernelconfig-building] chapter of the FreeBSD " +"Handbook. If this is not the case, please read through the above mentioned " +"chapter to understand how the build process works." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:64 +#, no-wrap +msgid "Building the Faster but Brittle Way" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:68 +msgid "" +"Building the kernel this way may be useful when working on the kernel code " +"and it may actually be faster than the documented procedure when only a " +"single option or two were tweaked in the kernel configuration file. On the " +"other hand, it might lead to unexpected kernel build breakage." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:71 +msgid "Run man:config[8] to generate the kernel source code:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:75 +#, no-wrap +msgid "# /usr/sbin/config MYKERNEL\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:78 +msgid "" +"Change into the build directory. man:config[8] will print the name of this " +"directory after being run as above." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:82 +#, no-wrap +msgid "# cd ../compile/MYKERNEL\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:85 +msgid "Compile the kernel:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:90 +#, no-wrap +msgid "" +"# make depend\n" +"# make\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:93 +msgid "Install the new kernel:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kernelbuild/_index.adoc:97 +#, no-wrap +msgid "# make install\n" +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc b/documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc index ed0a698d96..f56cd4cd0a 100644 --- a/documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc +++ b/documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc @@ -10,7 +10,7 @@ description: FreeBSD Kernel Debugging tags: ["Debugging", "Dump", "kgdb", "DDB", "GDB"] showBookMenu: true weight: 13 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/kerneldebug/" --- [[kerneldebug]] diff --git a/documentation/content/en/books/developers-handbook/kerneldebug/_index.po b/documentation/content/en/books/developers-handbook/kerneldebug/_index.po new file mode 100644 index 0000000000..4dae2e378f --- /dev/null +++ b/documentation/content/en/books/developers-handbook/kerneldebug/_index.po @@ -0,0 +1,1681 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-02-01 10:28-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: description +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:1 +#, no-wrap +msgid "FreeBSD Kernel Debugging" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:1 +#, no-wrap +msgid "Chapter 10. Kernel Debugging" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:17 +#, no-wrap +msgid "Kernel Debugging" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:55 +#, no-wrap +msgid "Obtaining a Kernel Crash Dump" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:60 +msgid "" +"When running a development kernel (e.g., FreeBSD-CURRENT), such as a kernel " +"under extreme conditions (e.g., very high load averages, tens of thousands " +"of connections, exceedingly high number of concurrent users, hundreds of man:" +"jail[8]s, etc.), or using a new feature or device driver on FreeBSD-STABLE " +"(e.g., PAE), sometimes a kernel will panic. In the event that it does, this " +"chapter will demonstrate how to extract useful information out of a crash." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:65 +msgid "" +"A system reboot is inevitable once a kernel panics. Once a system is " +"rebooted, the contents of a system's physical memory (RAM) is lost, as well " +"as any bits that are on the swap device before the panic. To preserve the " +"bits in physical memory, the kernel makes use of the swap device as a " +"temporary place to store the bits that are in RAM across a reboot after a " +"crash. In doing this, when FreeBSD boots after a crash, a kernel image can " +"now be extracted and debugging can take place." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:71 +msgid "" +"A swap device that has been configured as a dump device still acts as a swap " +"device. Dumps to non-swap devices (such as tapes or CDRWs, for example) are " +"not supported at this time. A \"swap device\" is synonymous with a \"swap " +"partition.\"" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:74 +msgid "Several types of kernel crash dumps are available:" +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:75 +#, no-wrap +msgid "Full memory dumps" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:77 +msgid "Hold the complete contents of physical memory." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:78 +#, no-wrap +msgid "Minidumps" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:80 +msgid "Hold only memory pages in use by the kernel (FreeBSD 6.2 and higher)." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:81 +#, no-wrap +msgid "Textdumps" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:83 +msgid "" +"Hold captured, scripted, or interactive debugger output (FreeBSD 7.1 and " +"higher)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:85 +msgid "" +"Minidumps are the default dump type as of FreeBSD 7.0, and in most cases " +"will capture all necessary information present in a full memory dump, as " +"most problems can be isolated only using kernel state." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:87 +#, no-wrap +msgid "Configuring the Dump Device" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:95 +msgid "" +"Before the kernel will dump the contents of its physical memory to a dump " +"device, a dump device must be configured. A dump device is specified by " +"using the man:dumpon[8] command to tell the kernel where to save kernel " +"crash dumps. The man:dumpon[8] program must be called after the swap " +"partition has been configured with man:swapon[8]. This is normally handled " +"by setting the `dumpdev` variable in man:rc.conf[5] to the path of the swap " +"device (the recommended way to extract a kernel dump) or `AUTO` to use the " +"first configured swap device. The default for `dumpdev` is `AUTO` in HEAD, " +"and changed to `NO` on RELENG_* branches (except for RELENG_7, which was " +"left set to `AUTO`). On FreeBSD 9.0-RELEASE and later versions, bsdinstall " +"will ask whether crash dumps should be enabled on the target system during " +"the install process." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:99 +msgid "" +"Check [.filename]#/etc/fstab# or man:swapinfo[8] for a list of swap devices." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:104 +msgid "" +"Make sure the `dumpdir` specified in man:rc.conf[5] exists before a kernel " +"crash!" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:109 +#, no-wrap +msgid "" +"# mkdir /var/crash\n" +"# chmod 700 /var/crash\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:112 +msgid "" +"Also, remember that the contents of [.filename]#/var/crash# is sensitive and " +"very likely contains confidential information such as passwords." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:115 +#, no-wrap +msgid "Extracting a Kernel Dump" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:121 +msgid "" +"Once a dump has been written to a dump device, the dump must be extracted " +"before the swap device is mounted. To extract a dump from a dump device, " +"use the man:savecore[8] program. If `dumpdev` has been set in man:rc." +"conf[5], man:savecore[8] will be called automatically on the first multi-" +"user boot after the crash and before the swap device is mounted. The " +"location of the extracted core is placed in the man:rc.conf[5] value " +"`dumpdir`, by default [.filename]#/var/crash# and will be named [." +"filename]#vmcore.0#." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:125 +msgid "" +"In the event that there is already a file called [.filename]#vmcore.0# in [." +"filename]#/var/crash# (or whatever `dumpdir` is set to), the kernel will " +"increment the trailing number for every crash to avoid overwriting an " +"existing [.filename]#vmcore# (e.g., [.filename]#vmcore.1#). man:savecore[8] " +"will always create a symbolic link to named [.filename]#vmcore.last# in [." +"filename]#/var/crash# after a dump is saved. This symbolic link can be used " +"to locate the name of the most recent dump." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:129 +msgid "" +"The man:crashinfo[8] utility generates a text file containing a summary of " +"information from a full memory dump or minidump. If `dumpdev` has been set " +"in man:rc.conf[5], man:crashinfo[8] will be invoked automatically after man:" +"savecore[8]. The output is saved to a file in `dumpdir` named [." +"filename]#core.txt.N#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:134 +msgid "" +"If you are testing a new kernel but need to boot a different one in order to " +"get your system up and running again, boot it only into single user mode " +"using the `-s` flag at the boot prompt, and then perform the following steps:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:141 +#, no-wrap +msgid "" +"# fsck -p\n" +"# mount -a -t ufs # make sure /var/crash is writable\n" +"# savecore /var/crash /dev/ad0s1b\n" +"# exit # exit to multi-user\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:146 +msgid "" +"This instructs man:savecore[8] to extract a kernel dump from [.filename]#/" +"dev/ad0s1b# and place the contents in [.filename]#/var/crash#. Do not " +"forget to make sure the destination directory [.filename]#/var/crash# has " +"enough space for the dump. Also, do not forget to specify the correct path " +"to your swap device as it is likely different than [.filename]#/dev/ad0s1b#!" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:148 +#, no-wrap +msgid "Testing Kernel Dump Configuration" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:153 +msgid "" +"The kernel includes a man:sysctl[8] node that requests a kernel panic. This " +"can be used to verify that your system is properly configured to save kernel " +"crash dumps. You may wish to remount existing file systems as read-only in " +"single user mode before triggering the crash to avoid data loss." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:163 +#, no-wrap +msgid "" +"# shutdown now\n" +"...\n" +"Enter full pathname of shell or RETURN for /bin/sh:\n" +"# mount -a -u -r\n" +"# sysctl debug.kdb.panic=1\n" +"debug.kdb.panic:panic: kdb_sysctl_panic\n" +"...\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:166 +msgid "" +"After rebooting, your system should save a dump in [.filename]#/var/crash# " +"along with a matching summary from man:crashinfo[8]." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:168 +#, no-wrap +msgid "Debugging a Kernel Crash Dump with `kgdb`" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:175 +msgid "" +"This section covers man:kgdb[1]. The latest version is included in the " +"package:devel/gdb[]. An older version is also present in FreeBSD 11 and " +"earlier." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:178 +msgid "" +"To enter into the debugger and begin getting information from the dump, " +"start kgdb:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:182 +#, no-wrap +msgid "# kgdb -n N\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:186 +msgid "" +"Where _N_ is the suffix of the [.filename]#vmcore.N# to examine. To open " +"the most recent dump use:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:190 +#, no-wrap +msgid "# kgdb -n last\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:194 +msgid "" +"Normally, man:kgdb[1] should be able to locate the kernel running at the " +"time the dump was generated. If it is not able to locate the correct " +"kernel, pass the pathname of the kernel and dump as two arguments to kgdb:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:198 +#, no-wrap +msgid "# kgdb /boot/kernel/kernel /var/crash/vmcore.0\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:201 +msgid "" +"You can debug the crash dump using the kernel sources just like you can for " +"any other program." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:208 +msgid "" +"This dump is from a 5.2-BETA kernel and the crash comes from deep within the " +"kernel. The output below has been modified to include line numbers on the " +"left. This first trace inspects the instruction pointer and obtains a back " +"trace. The address that is used on line 41 for the `list` command is the " +"instruction pointer and can be found on line 17. Most developers will " +"request having at least this information sent to them if you are unable to " +"debug the problem yourself. If, however, you do solve the problem, make " +"sure that your patch winds its way into the source tree via a problem " +"report, mailing lists, or by being able to commit it!" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:301 +#, no-wrap +msgid "" +" 1:# cd /usr/obj/usr/src/sys/KERNCONF\n" +" 2:# kgdb kernel.debug /var/crash/vmcore.0\n" +" 3:GNU gdb 5.2.1 (FreeBSD)\n" +" 4:Copyright 2002 Free Software Foundation, Inc.\n" +" 5:GDB is free software, covered by the GNU General Public License, and you are\n" +" 6:welcome to change it and/or distribute copies of it under certain conditions.\n" +" 7:Type \"show copying\" to see the conditions.\n" +" 8:There is absolutely no warranty for GDB. Type \"show warranty\" for details.\n" +" 9:This GDB was configured as \"i386-undermydesk-freebsd\"...\n" +"10:panic: page fault\n" +"11:panic messages:\n" +"12:---\n" +"13:Fatal trap 12: page fault while in kernel mode\n" +"14:cpuid = 0; apic id = 00\n" +"15:fault virtual address = 0x300\n" +"16:fault code: = supervisor read, page not present\n" +"17:instruction pointer = 0x8:0xc0713860\n" +"18:stack pointer = 0x10:0xdc1d0b70\n" +"19:frame pointer = 0x10:0xdc1d0b7c\n" +"20:code segment = base 0x0, limit 0xfffff, type 0x1b\n" +"21: = DPL 0, pres 1, def32 1, gran 1\n" +"22:processor eflags = resume, IOPL = 0\n" +"23:current process = 14394 (uname)\n" +"24:trap number = 12\n" +"25:panic: page fault\n" +"26 cpuid = 0;\n" +"27:Stack backtrace:\n" +"28\n" +"29:syncing disks, buffers remaining... 2199 2199 panic: mi_switch: switch in a critical section\n" +"30:cpuid = 0;\n" +"31:Uptime: 2h43m19s\n" +"32:Dumping 255 MB\n" +"33: 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240\n" +"34:---\n" +"35:Reading symbols from /boot/kernel/snd_maestro3.ko...done.\n" +"36:Loaded symbols for /boot/kernel/snd_maestro3.ko\n" +"37:Reading symbols from /boot/kernel/snd_pcm.ko...done.\n" +"38:Loaded symbols for /boot/kernel/snd_pcm.ko\n" +"39:#0 doadump () at /usr/src/sys/kern/kern_shutdown.c:240\n" +"40:240 dumping++;\n" +"41:(kgdb) list *0xc0713860\n" +"42:0xc0713860 is in lapic_ipi_wait (/usr/src/sys/i386/i386/local_apic.c:663).\n" +"43:658 incr = 0;\n" +"44:659 delay = 1;\n" +"45:660 } else\n" +"46:661 incr = 1;\n" +"47:662 for (x = 0; x < delay; x += incr) {\n" +"48:663 if ((lapic->icr_lo & APIC_DELSTAT_MASK) == APIC_DELSTAT_IDLE)\n" +"49:664 return (1);\n" +"50:665 ia32_pause();\n" +"51:666 }\n" +"52:667 return (0);\n" +"53:(kgdb) backtrace\n" +"54:#0 doadump () at /usr/src/sys/kern/kern_shutdown.c:240\n" +"55:#1 0xc055fd9b in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:372\n" +"56:#2 0xc056019d in panic () at /usr/src/sys/kern/kern_shutdown.c:550\n" +"57:#3 0xc0567ef5 in mi_switch () at /usr/src/sys/kern/kern_synch.c:470\n" +"58:#4 0xc055fa87 in boot (howto=256) at /usr/src/sys/kern/kern_shutdown.c:312\n" +"59:#5 0xc056019d in panic () at /usr/src/sys/kern/kern_shutdown.c:550\n" +"60:#6 0xc0720c66 in trap_fatal (frame=0xdc1d0b30, eva=0)\n" +"61: at /usr/src/sys/i386/i386/trap.c:821\n" +"62:#7 0xc07202b3 in trap (frame=\n" +"63: {tf_fs = -1065484264, tf_es = -1065484272, tf_ds = -1065484272, tf_edi = 1, tf_esi = 0, tf_ebp = -602076292, tf_isp = -602076324, tf_ebx = 0, tf_edx = 0, tf_ecx = 1000000, tf_eax = 243, tf_trapno = 12, tf_err = 0, tf_eip = -1066321824, tf_cs = 8, tf_eflags = 65671, tf_esp = 243, tf_ss = 0})\n" +"64: at /usr/src/sys/i386/i386/trap.c:250\n" +"65:#8 0xc070c9f8 in calltrap () at {standard input}:94\n" +"66:#9 0xc07139f3 in lapic_ipi_vectored (vector=0, dest=0)\n" +"67: at /usr/src/sys/i386/i386/local_apic.c:733\n" +"68:#10 0xc0718b23 in ipi_selected (cpus=1, ipi=1)\n" +"69: at /usr/src/sys/i386/i386/mp_machdep.c:1115\n" +"70:#11 0xc057473e in kseq_notify (ke=0xcc05e360, cpu=0)\n" +"71: at /usr/src/sys/kern/sched_ule.c:520\n" +"72:#12 0xc0575cad in sched_add (td=0xcbcf5c80)\n" +"73: at /usr/src/sys/kern/sched_ule.c:1366\n" +"74:#13 0xc05666c6 in setrunqueue (td=0xcc05e360)\n" +"75: at /usr/src/sys/kern/kern_switch.c:422\n" +"76:#14 0xc05752f4 in sched_wakeup (td=0xcbcf5c80)\n" +"77: at /usr/src/sys/kern/sched_ule.c:999\n" +"78:#15 0xc056816c in setrunnable (td=0xcbcf5c80)\n" +"79: at /usr/src/sys/kern/kern_synch.c:570\n" +"80:#16 0xc0567d53 in wakeup (ident=0xcbcf5c80)\n" +"81: at /usr/src/sys/kern/kern_synch.c:411\n" +"82:#17 0xc05490a8 in exit1 (td=0xcbcf5b40, rv=0)\n" +"83: at /usr/src/sys/kern/kern_exit.c:509\n" +"84:#18 0xc0548011 in sys_exit () at /usr/src/sys/kern/kern_exit.c:102\n" +"85:#19 0xc0720fd0 in syscall (frame=\n" +"86: {tf_fs = 47, tf_es = 47, tf_ds = 47, tf_edi = 0, tf_esi = -1, tf_ebp = -1077940712, tf_isp = -602075788, tf_ebx = 672411944, tf_edx = 10, tf_ecx = 672411600, tf_eax = 1, tf_trapno = 12, tf_err = 2, tf_eip = 671899563, tf_cs = 31, tf_eflags = 642, tf_esp = -1077940740, tf_ss = 47})\n" +"87: at /usr/src/sys/i386/i386/trap.c:1010\n" +"88:#20 0xc070ca4d in Xint0x80_syscall () at {standard input}:136\n" +"89:---Can't read userspace from dump, or kernel process---\n" +"90:(kgdb) quit\n" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:307 +msgid "" +"If your system is crashing regularly and you are running out of disk space, " +"deleting old [.filename]#vmcore# files in [.filename]#/var/crash# could save " +"a considerable amount of disk space!" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:310 +#, no-wrap +msgid "On-Line Kernel Debugging Using DDB" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:314 +msgid "" +"While `kgdb` as an off-line debugger provides a very high level of user " +"interface, there are some things it cannot do. The most important ones " +"being breakpointing and single-stepping kernel code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:318 +msgid "" +"If you need to do low-level debugging on your kernel, there is an on-line " +"debugger available called DDB. It allows setting of breakpoints, single-" +"stepping kernel functions, examining and changing kernel variables, etc. " +"However, it cannot access kernel source files, and only has access to the " +"global and static symbols, not to the full debug information like `kgdb` " +"does." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:320 +msgid "To configure your kernel to include DDB, add the options" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:323 +#, no-wrap +msgid "options KDB\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:328 +#, no-wrap +msgid "options DDB\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:332 +msgid "" +"to your config file, and rebuild. (See extref:{handbook}[The FreeBSD " +"Handbook] for details on configuring the FreeBSD kernel)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:338 +msgid "" +"Once your DDB kernel is running, there are several ways to enter DDB. The " +"first, and earliest way is to use the boot flag `-d`. The kernel will start " +"up in debug mode and enter DDB prior to any device probing. Hence you can " +"even debug the device probe/attach functions. To use this, exit the " +"loader's boot menu and enter `boot -d` at the loader prompt." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:342 +msgid "" +"The second scenario is to drop to the debugger once the system has booted. " +"There are two simple ways to accomplish this. If you would like to break to " +"the debugger from the command prompt, simply type the command:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:346 +#, no-wrap +msgid "# sysctl debug.kdb.enter=1\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:353 +msgid "" +"Alternatively, if you are at the system console, you may use a hot-key on " +"the keyboard. The default break-to-debugger sequence is kbd:[Ctrl+Alt" +"+ESC]. For syscons, this sequence can be remapped and some of the " +"distributed maps out there do this, so check to make sure you know the right " +"sequence to use. There is an option available for serial consoles that " +"allows the use of a serial line BREAK on the console line to enter DDB " +"(`options BREAK_TO_DEBUGGER` in the kernel config file). It is not the " +"default since there are a lot of serial adapters around that gratuitously " +"generate a BREAK condition, for example when pulling the cable." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:356 +msgid "" +"The third way is that any panic condition will branch to DDB if the kernel " +"is configured to use it. For this reason, it is not wise to configure a " +"kernel with DDB for a machine running unattended." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:358 +msgid "To obtain the unattended functionality, add:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:362 +#, no-wrap +msgid "options\tKDB_UNATTENDED\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:365 +msgid "to the kernel configuration file and rebuild/reinstall." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:368 +msgid "" +"The DDB commands roughly resemble some `gdb` commands. The first thing you " +"probably need to do is to set a breakpoint:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:372 +#, no-wrap +msgid " break function-name address\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:377 +msgid "" +"Numbers are taken hexadecimal by default, but to make them distinct from " +"symbol names; hexadecimal numbers starting with the letters `a-f` need to be " +"preceded with `0x` (this is optional for other numbers). Simple expressions " +"are allowed, for example: `function-name + 0x103`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:379 +msgid "To exit the debugger and continue execution, type:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:383 +#, no-wrap +msgid " continue\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:386 +msgid "To get a stack trace of the current thread, use:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:390 +#, no-wrap +msgid " trace\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:393 +msgid "" +"To get a stack trace of an arbitrary thread, specify a process ID or thread " +"ID as a second argument to `trace`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:395 +msgid "If you want to remove a breakpoint, use" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:400 +#, no-wrap +msgid "" +" del\n" +" del address-expression\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:404 +msgid "" +"The first form will be accepted immediately after a breakpoint hit, and " +"deletes the current breakpoint. The second form can remove any breakpoint, " +"but you need to specify the exact address; this can be obtained from:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:408 +#, no-wrap +msgid " show b\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:411 +msgid "or:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:415 +#, no-wrap +msgid " show break\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:418 +msgid "To single-step the kernel, try:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:422 +#, no-wrap +msgid " s\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:425 +msgid "" +"This will step into functions, but you can make DDB trace them until the " +"matching return statement is reached by:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:429 +#, no-wrap +msgid " n\n" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:435 +msgid "" +"This is different from ``gdb``'s `next` statement; it is like ``gdb``'s " +"`finish`. Pressing kbd:[n] more than once will cause a continue." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:438 +msgid "To examine data from memory, use (for example):" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:445 +#, no-wrap +msgid "" +" x/wx 0xf0133fe0,40\n" +" x/hd db_symtab_space\n" +" x/bc termbuf,10\n" +" x/s stringbuf\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:450 +msgid "" +"for word/halfword/byte access, and hexadecimal/decimal/character/ string " +"display. The number after the comma is the object count. To display the " +"next 0x10 items, simply use:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:454 +#, no-wrap +msgid " x ,10\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:457 +msgid "Similarly, use" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:461 +#, no-wrap +msgid " x/ia foofunc,10\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:464 +msgid "" +"to disassemble the first 0x10 instructions of `foofunc`, and display them " +"along with their offset from the beginning of `foofunc`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:466 +msgid "To modify memory, use the write command:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:471 +#, no-wrap +msgid "" +" w/b termbuf 0xa 0xb 0\n" +" w/w 0xf0010030 0 0\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:475 +msgid "" +"The command modifier (`b`/`h`/`w`) specifies the size of the data to be " +"written, the first following expression is the address to write to and the " +"remainder is interpreted as data to write to successive memory locations." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:477 +msgid "If you need to know the current registers, use:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:481 +#, no-wrap +msgid " show reg\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:484 +msgid "Alternatively, you can display a single register value by e.g." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:488 +#, no-wrap +msgid " p $eax\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:491 +msgid "and modify it by:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:495 +#, no-wrap +msgid " set $eax new-value\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:498 +msgid "Should you need to call some kernel functions from DDB, simply say:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:502 +#, no-wrap +msgid " call func(arg1, arg2, ...)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:505 +msgid "The return value will be printed." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:507 +msgid "For a man:ps[1] style summary of all running processes, use:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:511 +#, no-wrap +msgid " ps\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:516 +msgid "" +"Now you have examined why your kernel failed, and you wish to reboot. " +"Remember that, depending on the severity of previous malfunctioning, not all " +"parts of the kernel might still be working as expected. Perform one of the " +"following actions to shut down and reboot your system:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:520 +#, no-wrap +msgid " panic\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:523 +msgid "" +"This will cause your kernel to dump core and reboot, so you can later " +"analyze the core on a higher level with man:kgdb[1]." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:527 +#, no-wrap +msgid " call boot(0)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:531 +msgid "" +"Might be a good way to cleanly shut down the running system, `sync()` all " +"disks, and finally, in some cases, reboot. As long as the disk and " +"filesystem interfaces of the kernel are not damaged, this could be a good " +"way for an almost clean shutdown." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:535 +#, no-wrap +msgid " reset\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:538 +msgid "" +"This is the final way out of disaster and almost the same as hitting the Big " +"Red Button." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:540 +msgid "If you need a short command summary, simply type:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:544 +#, no-wrap +msgid " help\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:548 +msgid "" +"It is highly recommended to have a printed copy of the man:ddb[4] manual " +"page ready for a debugging session. Remember that it is hard to read the on-" +"line manual while single-stepping the kernel." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:550 +#, no-wrap +msgid "On-Line Kernel Debugging Using Remote GDB" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:554 +msgid "" +"The FreeBSD kernel provides a second KDB backend for on-line debugging: man:" +"gdb[4]. This feature has been supported since FreeBSD 2.2, and it is " +"actually a very neat one." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:560 +msgid "" +"GDB has supported _remote debugging_ for a long time. This is done using a " +"very simple protocol along a serial line. Unlike the other debugging " +"methods described above, you will need two machines for doing this. One is " +"the host providing the debugging environment, including all the sources, and " +"a copy of the kernel binary with all the symbols in it. The other is the " +"target machine that runs a copy of the very same kernel (optionally stripped " +"of the debugging information)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:562 +msgid "" +"In order to use remote GDB, ensure that the following options are present in " +"your kernel configuration:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:567 +#, no-wrap +msgid "" +"makeoptions DEBUG=-g\n" +"options KDB\n" +"options GDB\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:570 +msgid "" +"Note that the `GDB` option is turned off by default in `GENERIC` kernels on -" +"STABLE and -RELEASE branches, but enabled on -CURRENT." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:574 +msgid "" +"Once built, copy the kernel to the target machine, and boot it. Connect the " +"serial line of the target machine that has \"flags 080\" set on its uart " +"device to any serial line of the debugging host. See man:uart[4] for " +"information on how to set the flags on a uart device." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:577 +msgid "" +"The target machine must be made to enter the GDB backend, either due to a " +"panic or by taking a purposeful trap into the debugger. Before doing this, " +"select the GDB debugger backend:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:581 +#, no-wrap +msgid "" +"# sysctl debug.kdb.current=gdb\n" +"debug.kdb.current: ddb -> gdb\n" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:588 +msgid "" +"The supported backends can be listed by the `debug.kdb.available` sysctl. " +"If the kernel configuration includes `options DDB`, then man:ddb[4] will be " +"selected by default. If `gdb` does not appear in the list of available " +"backends, then the debug serial port may not have been configured correctly." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:591 +msgid "Then, force entry to the debugger:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:595 +#, no-wrap +msgid "" +"# sysctl debug.kdb.enter=1\n" +"debug.kdb.enter: 0KDB: enter: sysctl debug.kdb.enter\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:599 +msgid "" +"The target machine now awaits connection from a remote GDB client. On the " +"debugging machine, go to the compile directory of the target kernel, and " +"start `gdb`:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:610 +#, no-wrap +msgid "" +"# cd /usr/obj/usr/src/amd64.amd64/sys/GENERIC/\n" +"# kgdb kernel\n" +"GNU gdb (GDB) 10.2 [GDB v10.2 for FreeBSD]\n" +"Copyright (C) 2021 Free Software Foundation, Inc.\n" +"...\n" +"Reading symbols from kernel...\n" +"Reading symbols from /usr/obj/usr/src/amd64.amd64/sys/GENERIC/kernel.debug...\n" +"(kgdb)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:613 +msgid "" +"Initialize the remote debugging session (assuming the first serial port is " +"being used) by:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:617 +#, no-wrap +msgid "(kgdb) target remote /dev/cuau0\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:620 +msgid "Your hosting GDB will now gain control over the target kernel:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:627 +#, no-wrap +msgid "" +"Remote debugging using /dev/cuau0\n" +"kdb_enter (why=<optimized out>, msg=<optimized out>) at /usr/src/sys/kern/subr_kdb.c:506\n" +"506 kdb_why = KDB_WHY_UNSET;\n" +"(kgdb)\n" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:635 +msgid "" +"Depending on the compiler used, some local variables may appear as " +"`<optimized out>`, preventing them from being inspected directly by `gdb`. " +"If this causes problems while debugging, it is possible to build the kernel " +"at a decreased optimization level, which may improve the visibility of some " +"variables. This can be done by passing `COPTFLAGS=-O1` to man:make[1]. " +"However, certain classes of kernel bugs may manifest differently (or not at " +"all) when the optimization level is changed." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:639 +msgid "" +"You can use this session almost as any other GDB session, including full " +"access to the source, running it in gud-mode inside an Emacs window (which " +"gives you an automatic source code display in another Emacs window), etc." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:641 +#, no-wrap +msgid "Debugging a Console Driver" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:647 +msgid "" +"Since you need a console driver to run DDB on, things are more complicated " +"if the console driver itself is failing. You might remember the use of a " +"serial console (either with modified boot blocks, or by specifying `-h` at " +"the `Boot:` prompt), and hook up a standard terminal onto your first serial " +"port. DDB works on any configured console driver, including a serial " +"console." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:649 +#, no-wrap +msgid "Debugging Deadlocks" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:654 +msgid "" +"You may experience so called deadlocks, a situation where a system stops " +"doing useful work. To provide a helpful bug report in this situation, use " +"man:ddb[4] as described in the previous section. Include the output of `ps` " +"and `trace` for suspected processes in the report." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:658 +msgid "" +"If possible, consider doing further investigation. The recipe below is " +"especially useful if you suspect that a deadlock occurs in the VFS layer. " +"Add these options to the kernel configuration file." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:669 +#, no-wrap +msgid "" +"makeoptions \tDEBUG=-g\n" +"options \tINVARIANTS\n" +"options \tINVARIANT_SUPPORT\n" +"options \tWITNESS\n" +"options \tWITNESS_SKIPSPIN\n" +"options \tDEBUG_LOCKS\n" +"options \tDEBUG_VFS_LOCKS\n" +"options \tDIAGNOSTIC\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:672 +msgid "" +"When a deadlock occurs, in addition to the output of the `ps` command, " +"provide information from the `show pcpu`, `show allpcpu`, `show locks`, " +"`show alllocks`, `show lockedvnods` and `alltrace`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:674 +msgid "" +"To obtain meaningful backtraces for threaded processes, use `thread thread-" +"id` to switch to the thread stack, and do a backtrace with `where`." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:676 +#, no-wrap +msgid "Kernel debugging with Dcons" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:682 +msgid "" +"man:dcons[4] is a very simple console driver that is not directly connected " +"with any physical devices. It just reads and writes characters from and to " +"a buffer in a kernel or loader. Due to its simple nature, it is very useful " +"for kernel debugging, especially with a FireWire(R) device. Currently, " +"FreeBSD provides two ways to interact with the buffer from outside of the " +"kernel using man:dconschat[8]." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:683 +#, no-wrap +msgid "Dcons over FireWire(R)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:691 +msgid "" +"Most FireWire(R) (IEEE1394) host controllers are based on the OHCI " +"specification that supports physical access to the host memory. This means " +"that once the host controller is initialized, we can access the host memory " +"without the help of software (kernel). We can exploit this facility for " +"interaction with man:dcons[4]. man:dcons[4] provides similar functionality " +"as a serial console. It emulates two serial ports, one for the console and " +"DDB, the other for GDB. Since remote memory access is fully handled by the " +"hardware, the man:dcons[4] buffer is accessible even when the system crashes." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:694 +msgid "" +"FireWire(R) devices are not limited to those integrated into motherboards. " +"PCI cards exist for desktops, and a cardbus interface can be purchased for " +"laptops." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:695 +#, no-wrap +msgid "Enabling FireWire(R) and Dcons support on the target machine" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:698 +msgid "" +"To enable FireWire(R) and Dcons support in the kernel of the _target " +"machine_:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:700 +msgid "" +"Make sure your kernel supports `dcons`, `dcons_crom` and `firewire`. `Dcons` " +"should be statically linked with the kernel. For `dcons_crom` and " +"`firewire`, modules should be OK." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:701 +msgid "" +"Make sure physical DMA is enabled. You may need to add `hw.firewire." +"phydma_enable=1` to [.filename]#/boot/loader.conf#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:702 +msgid "Add options for debugging." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:703 +msgid "" +"Add `dcons_gdb=1` in [.filename]#/boot/loader.conf# if you use GDB over " +"FireWire(R)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:704 +msgid "Enable `dcons` in [.filename]#/etc/ttys#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:705 +msgid "" +"Optionally, to force `dcons` to be the high-level console, add `hw.firewire." +"dcons_crom.force_console=1` to [.filename]#loader.conf#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:707 +msgid "" +"To enable FireWire(R) and Dcons support in man:loader[8] on i386 or amd64:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:709 +msgid "" +"Add `LOADER_FIREWIRE_SUPPORT=YES` in [.filename]#/etc/make.conf# and rebuild " +"man:loader[8]:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:713 +#, no-wrap +msgid "# cd /sys/boot/i386 && make clean && make && make install\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:716 +msgid "" +"To enable man:dcons[4] as an active low-level console, add `boot_multicons=" +"\"YES\"` to [.filename]#/boot/loader.conf#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:719 +msgid "" +"Here are a few configuration examples. A sample kernel configuration file " +"would contain:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:728 +#, no-wrap +msgid "" +"device dcons\n" +"device dcons_crom\n" +"options KDB\n" +"options DDB\n" +"options GDB\n" +"options ALT_BREAK_TO_DEBUGGER\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:731 +msgid "And a sample [.filename]#/boot/loader.conf# would contain:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:739 +#, no-wrap +msgid "" +"dcons_crom_load=\"YES\"\n" +"dcons_gdb=1\n" +"boot_multicons=\"YES\"\n" +"hw.firewire.phydma_enable=1\n" +"hw.firewire.dcons_crom.force_console=1\n" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:741 +#, no-wrap +msgid "Enabling FireWire(R) and Dcons support on the host machine" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:744 +msgid "To enable FireWire(R) support in the kernel on the _host machine_:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:748 +#, no-wrap +msgid "# kldload firewire\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:751 +msgid "" +"Find out the EUI64 (the unique 64 bit identifier) of the FireWire(R) host " +"controller, and use man:fwcontrol[8] or `dmesg` to find the EUI64 of the " +"target machine." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:753 +msgid "Run man:dconschat[8], with:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:757 +#, no-wrap +msgid "# dconschat -e \\# -br -G 12345 -t 00-11-22-33-44-55-66-77\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:760 +msgid "" +"The following key combinations can be used once man:dconschat[8] is running:" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:766 +#, no-wrap +msgid "kbd:[~+.]" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:768 +#, no-wrap +msgid "Disconnect" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:769 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:772 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:775 +#, no-wrap +msgid "kbd:[~]" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:771 +#, no-wrap +msgid "ALT BREAK" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:774 +#, no-wrap +msgid "RESET target" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:776 +#, no-wrap +msgid "Suspend dconschat" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:779 +msgid "" +"Attach remote GDB by starting man:kgdb[1] with a remote debugging session:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:783 +#, no-wrap +msgid " kgdb -r :12345 kernel\n" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:785 +#, no-wrap +msgid "Some general tips" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:788 +msgid "Here are some general tips:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:790 +msgid "" +"To take full advantage of the speed of FireWire(R), disable other slow " +"console drivers:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:795 +#, no-wrap +msgid "" +"# conscontrol delete ttyd0\t # serial console\n" +"# conscontrol delete consolectl\t# video/keyboard\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:798 +msgid "" +"There exists a GDB mode for man:emacs[1]; this is what you will need to add " +"to your [.filename]#.emacs#:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:805 +#, no-wrap +msgid "" +"(setq gud-gdba-command-name \"kgdb -a -a -a -r :12345\")\n" +"(setq gdb-many-windows t)\n" +"(xterm-mouse-mode 1)\n" +"M-x gdba\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:808 +msgid "And for DDD ([.filename]#devel/ddd#):" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:815 +#, no-wrap +msgid "" +"# remote serial protocol\n" +"LANG=C ddd --debugger kgdb -r :12345 kernel\n" +"# live core debug\n" +"LANG=C ddd --debugger kgdb kernel /dev/fwmem0.2\n" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:817 +#, no-wrap +msgid "Dcons with KVM" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:821 +msgid "" +"We can directly read the man:dcons[4] buffer via [.filename]#/dev/mem# for " +"live systems, and in the core dump for crashed systems. These give you " +"similar output to `dmesg -a`, but the man:dcons[4] buffer includes more " +"information." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:822 +#, no-wrap +msgid "Using Dcons with KVM" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:825 +msgid "To use man:dcons[4] with KVM:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:827 +msgid "Dump a man:dcons[4] buffer of a live system:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:831 +#, no-wrap +msgid "# dconschat -1\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:834 +msgid "Dump a man:dcons[4] buffer of a crash dump:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:838 +#, no-wrap +msgid "# dconschat -1 -M vmcore.XX\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:841 +msgid "Live core debugging can be done via:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:846 +#, no-wrap +msgid "" +"# fwcontrol -m target_eui64\n" +"# kgdb kernel /dev/fwmem0.2\n" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:849 +#, no-wrap +msgid "Glossary of Kernel Options for Debugging" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:852 +msgid "" +"This section provides a brief glossary of compile-time kernel options used " +"for debugging:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:854 +msgid "" +"`options KDB`: compiles in the kernel debugger framework. Required for " +"`options DDB` and `options GDB`. Little or no performance overhead. By " +"default, the debugger will be entered on panic instead of an automatic " +"reboot." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:855 +msgid "" +"`options KDB_UNATTENDED`: change the default value of the `debug." +"debugger_on_panic` sysctl to 0, which controls whether the debugger is " +"entered on panic. When `options KDB` is not compiled into the kernel, the " +"behavior is to automatically reboot on panic; when it is compiled into the " +"kernel, the default behavior is to drop into the debugger unless `options " +"KDB_UNATTENDED` is compiled in. If you want to leave the kernel debugger " +"compiled into the kernel but want the system to come back up unless you're " +"on-hand to use the debugger for diagnostics, use this option." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:856 +msgid "" +"`options KDB_TRACE`: change the default value of the `debug.trace_on_panic` " +"sysctl to 1, which controls whether the debugger automatically prints a " +"stack trace on panic. Especially if running with `options KDB_UNATTENDED`, " +"this can be helpful to gather basic debugging information on the serial or " +"firewire console while still rebooting to recover." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:857 +msgid "" +"`options DDB`: compile in support for the console debugger, DDB. This " +"interactive debugger runs on whatever the active low-level console of the " +"system is, which includes the video console, serial console, or firewire " +"console. It provides basic integrated debugging facilities, such as stack " +"tracing, process and thread listing, dumping of lock state, VM state, file " +"system state, and kernel memory management. DDB does not require software " +"running on a second machine or being able to generate a core dump or full " +"debugging kernel symbols, and provides detailed diagnostics of the kernel at " +"run-time. Many bugs can be fully diagnosed using only DDB output. This " +"option depends on `options KDB`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:858 +msgid "" +"`options GDB`: compile in support for the remote debugger, GDB, which can " +"operate over serial cable or firewire. When the debugger is entered, GDB may " +"be attached to inspect structure contents, generate stack traces, etc. Some " +"kernel state is more awkward to access than in DDB, which is able to " +"generate useful summaries of kernel state automatically, such as " +"automatically walking lock debugging or kernel memory management structures, " +"and a second machine running the debugger is required. On the other hand, " +"GDB combines information from the kernel source and full debugging symbols, " +"and is aware of full data structure definitions, local variables, and is " +"scriptable. This option is not required to run GDB on a kernel core dump. " +"This option depends on `options KDB`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:859 +msgid "" +"`options BREAK_TO_DEBUGGER`, `options ALT_BREAK_TO_DEBUGGER`: allow a break " +"signal or alternative signal on the console to enter the debugger. If the " +"system hangs without a panic, this is a useful way to reach the debugger. " +"Due to the current kernel locking, a break signal generated on a serial " +"console is significantly more reliable at getting into the debugger, and is " +"generally recommended. This option has little or no performance impact." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:860 +msgid "" +"`options INVARIANTS`: compile into the kernel a large number of run-time " +"assertion checks and tests, which constantly test the integrity of kernel " +"data structures and the invariants of kernel algorithms. These tests can be " +"expensive, so are not compiled in by default, but help provide useful \"fail " +"stop\" behavior, in which certain classes of undesired behavior enter the " +"debugger before kernel data corruption occurs, making them easier to debug. " +"Tests include memory scrubbing and use-after-free testing, which is one of " +"the more significant sources of overhead. This option depends on `options " +"INVARIANT_SUPPORT`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:861 +msgid "" +"`options INVARIANT_SUPPORT`: many of the tests present in `options " +"INVARIANTS` require modified data structures or additional kernel symbols to " +"be defined." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:862 +msgid "" +"`options WITNESS`: this option enables run-time lock order tracking and " +"verification, and is an invaluable tool for deadlock diagnosis. WITNESS " +"maintains a graph of acquired lock orders by lock type, and checks the graph " +"at each acquire for cycles (implicit or explicit). If a cycle is detected, a " +"warning and stack trace are generated to the console, indicating that a " +"potential deadlock might have occurred. WITNESS is required in order to use " +"the `show locks`, `show witness` and `show alllocks` DDB commands. This " +"debug option has significant performance overhead, which may be somewhat " +"mitigated through the use of `options WITNESS_SKIPSPIN`. Detailed " +"documentation may be found in man:witness[4]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:863 +msgid "" +"`options WITNESS_SKIPSPIN`: disable run-time checking of spinlock lock order " +"with WITNESS. As spin locks are acquired most frequently in the scheduler, " +"and scheduler events occur often, this option can significantly speed up " +"systems running with WITNESS. This option depends on `options WITNESS`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:864 +msgid "" +"`options WITNESS_KDB`: change the default value of the `debug.witness.kdb` " +"sysctl to 1, which causes WITNESS to enter the debugger when a lock order " +"violation is detected, rather than simply printing a warning. This option " +"depends on `options WITNESS`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:865 +msgid "" +"`options SOCKBUF_DEBUG`: perform extensive run-time consistency checking on " +"socket buffers, which can be useful for debugging both socket bugs and race " +"conditions in protocols and device drivers that interact with sockets. This " +"option significantly impacts network performance, and may change the timing " +"in device driver races." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:866 +msgid "" +"`options DEBUG_VFS_LOCKS`: track lock acquisition points for lockmgr/vnode " +"locks, expanding the amount of information displayed by `show lockedvnods` " +"in DDB. This option has a measurable performance impact." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:867 +msgid "" +"`options DEBUG_MEMGUARD`: a replacement for the man:malloc[9] kernel memory " +"allocator that uses the VM system to detect reads or writes from allocated " +"memory after free. Details may be found in man:memguard[9]. This option has " +"a significant performance impact, but can be very helpful in debugging " +"kernel memory corruption bugs." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:868 +msgid "" +"`options DIAGNOSTIC`: enable additional, more expensive diagnostic tests " +"along the lines of `options INVARIANTS`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:869 +msgid "" +"`options KASAN`: enable the Kernel Address Sanitizer. This enables compiler " +"instrumentation which can be used to detect invalid memory accesses in the " +"kernel, such as use-after-frees and buffer overflows. This largely " +"supersedes `options DEBUG_MEMGUARD`. See man:kasan[9] for details, and for " +"the currently supported platforms." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/kerneldebug/_index.adoc:869 +msgid "" +"`options KMSAN`: enable the Kernel Memory Sanitizer. This enables compiler " +"instrumentation which can be used to detect uses of uninitialized memory. " +"See man:kmsan[9] for details, and for the currently supported platforms." +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/l10n/_index.adoc b/documentation/content/en/books/developers-handbook/l10n/_index.adoc index 1cb5226179..de7e83b655 100644 --- a/documentation/content/en/books/developers-handbook/l10n/_index.adoc +++ b/documentation/content/en/books/developers-handbook/l10n/_index.adoc @@ -7,7 +7,7 @@ description: Localization and Internationalization - L10N and I18N in FreeBSD tags: ["L10N", "I18N", "Localization", "Internationalization", "FreeBSD"] showBookMenu: true weight: 5 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/l10n/" --- [[l10n]] diff --git a/documentation/content/en/books/developers-handbook/l10n/_index.po b/documentation/content/en/books/developers-handbook/l10n/_index.po new file mode 100644 index 0000000000..92fe40e244 --- /dev/null +++ b/documentation/content/en/books/developers-handbook/l10n/_index.po @@ -0,0 +1,487 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-02-01 09:21-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: description +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:1 +#, no-wrap +msgid "Localization and Internationalization - L10N and I18N in FreeBSD" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:1 +#, no-wrap +msgid "Chapter 4. Localization and Internationalization - L10N and I18N" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:14 +#, no-wrap +msgid "Localization and Internationalization - L10N and I18N" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:52 +#, no-wrap +msgid "Programming I18N Compliant Applications" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:59 +msgid "" +"To make your application more useful for speakers of other languages, we " +"hope that you will program I18N compliant. The GNU gcc compiler and GUI " +"libraries like QT and GTK support I18N through special handling of strings. " +"Making a program I18N compliant is very easy. It allows contributors to " +"port your application to other languages quickly. Refer to the library " +"specific I18N documentation for more details." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:63 +msgid "" +"In contrast with common perception, I18N compliant code is easy to write. " +"Usually, it only involves wrapping your strings with library specific " +"functions. In addition, please be sure to allow for wide or multibyte " +"character support." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:64 +#, no-wrap +msgid "A Call to Unify the I18N Effort" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:69 +msgid "" +"It has come to our attention that the individual I18N/L10N efforts for each " +"country has been repeating each others' efforts. Many of us have been " +"reinventing the wheel repeatedly and inefficiently. We hope that the " +"various major groups in I18N could congregate into a group effort similar to " +"the Core Team's responsibility." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:72 +msgid "" +"Currently, we hope that, when you write or port I18N programs, you would " +"send it out to each country's related FreeBSD mailing list for testing. In " +"the future, we hope to create applications that work in all the languages " +"out-of-the-box without dirty hacks." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:75 +msgid "" +"The {freebsd-i18n} has been established. If you are an I18N/L10N developer, " +"please send your comments, ideas, questions, and anything you deem related " +"to it." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:76 +#, no-wrap +msgid "Perl and Python" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:80 +msgid "" +"Perl and Python have I18N and wide character handling libraries. Please use " +"them for I18N compliance." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:82 +#, no-wrap +msgid "Localized Messages with POSIX.1 Native Language Support (NLS)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:86 +msgid "" +"Beyond the basic I18N functions, like supporting various input encodings or " +"supporting national conventions, such as the different decimal separators, " +"at a higher level of I18N, it is possible to localize the messages written " +"to the output by the various programs. A common way of doing this is using " +"the POSIX.1 NLS functions, which are provided as a part of the FreeBSD base " +"system." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:88 +#, no-wrap +msgid "Organizing Localized Messages into Catalog Files" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:94 +msgid "" +"POSIX.1 NLS is based on catalog files, which contain the localized messages " +"in the desired encoding. The messages are organized into sets and each " +"message is identified by an integer number in the containing set. The " +"catalog files are conventionally named after the locale they contain " +"localized messages for, followed by the `.msg` extension. For instance, the " +"Hungarian messages for ISO8859-2 encoding should be stored in a file called " +"[.filename]#hu_HU.ISO8859-2#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:99 +msgid "" +"These catalog files are common text files that contain the numbered " +"messages. It is possible to write comments by starting the line with a `$` " +"sign. Set boundaries are also separated by special comments, where the " +"keyword `set` must directly follow the `$` sign. The `set` keyword is then " +"followed by the set number. For example:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:103 +#, no-wrap +msgid "$set 1\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:107 +msgid "" +"The actual message entries start with the message number and followed by the " +"localized message. The well-known modifiers from man:printf[3] are accepted:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:111 +#, no-wrap +msgid "15 \"File not found: %s\\n\"\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:117 +msgid "" +"The language catalog files have to be compiled into a binary form before " +"they can be opened from the program. This conversion is done with the man:" +"gencat[1] utility. Its first argument is the filename of the compiled " +"catalog and its further arguments are the input catalogs. The localized " +"messages can also be organized into more catalog files and then all of them " +"can be processed with man:gencat[1]." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:119 +#, no-wrap +msgid "Using the Catalog Files from the Source Code" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:130 +msgid "" +"Using the catalog files is simple. To use the related functions, [." +"filename]#nl_types.h# must be included. Before using a catalog, it has to " +"be opened with man:catopen[3]. The function takes two arguments. The first " +"parameter is the name of the installed and compiled catalog. Usually, the " +"name of the program is used, such as grep. This name will be used when " +"looking for the compiled catalog file. The man:catopen[3] call looks for " +"this file in [.filename]#/usr/share/nls/locale/catname# and in [.filename]#/" +"usr/local/share/nls/locale/catname#, where `locale` is the locale set and " +"`catname` is the catalog name being discussed. The second parameter is a " +"constant, which can have two values:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:132 +msgid "" +"`NL_CAT_LOCALE`, which means that the used catalog file will be based on " +"`LC_MESSAGES`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:133 +msgid "`0`, which means that `LANG` has to be used to open the proper catalog." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:136 +msgid "" +"The man:catopen[3] call returns a catalog identifier of type `nl_catd`. " +"Please refer to the manual page for a list of possible returned error codes." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:139 +msgid "" +"After opening a catalog man:catgets[3] can be used to retrieve a message. " +"The first parameter is the catalog identifier returned by man:catopen[3], " +"the second one is the number of the set, the third one is the number of the " +"messages, and the fourth one is a fallback message, which will be returned " +"if the requested message cannot be retrieved from the catalog file." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:141 +msgid "" +"After using the catalog file, it must be closed by calling man:catclose[3], " +"which has one argument, the catalog id." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:143 +#, no-wrap +msgid "A Practical Example" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:146 +msgid "" +"The following example will demonstrate an easy solution on how to use NLS " +"catalogs in a flexible way." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:148 +msgid "" +"The below lines need to be put into a common header file of the program, " +"which is included into all source files where localized messages are " +"necessary:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:155 +#, no-wrap +msgid "" +"#ifdef WITHOUT_NLS\n" +"#define getstr(n)\t nlsstr[n]\n" +"#else\n" +"#include nl_types.h\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:159 +#, no-wrap +msgid "" +"extern nl_catd\t\t catalog;\n" +"#define getstr(n)\t catgets(catalog, 1, n, nlsstr[n])\n" +"#endif\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:161 +#, no-wrap +msgid "extern char\t\t*nlsstr[];\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:164 +msgid "" +"Next, put these lines into the global declaration part of the main source " +"file:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:171 +#, no-wrap +msgid "" +"#ifndef WITHOUT_NLS\n" +"#include nl_types.h\n" +"nl_catd\t catalog;\n" +"#endif\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:181 +#, no-wrap +msgid "" +"/*\n" +" * Default messages to use when NLS is disabled or no catalog\n" +" * is found.\n" +" */\n" +"char *nlsstr[] = {\n" +" \"\",\n" +"/* 1*/ \"some random message\",\n" +"/* 2*/ \"some other message\"\n" +"};\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:184 +msgid "" +"Next come the real code snippets, which open, read, and close the catalog:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:190 +#, no-wrap +msgid "" +"#ifndef WITHOUT_NLS\n" +"\tcatalog = catopen(\"myapp\", NL_CAT_LOCALE);\n" +"#endif\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:192 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:196 +#, no-wrap +msgid "...\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:194 +#, no-wrap +msgid "printf(getstr(1));\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:200 +#, no-wrap +msgid "" +"#ifndef WITHOUT_NLS\n" +"\tcatclose(catalog);\n" +"#endif\n" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:202 +#, no-wrap +msgid "Reducing Strings to Localize" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:206 +msgid "" +"There is a good way of reducing the strings that need to be localized by " +"using libc error messages. This is also useful to just avoid duplication " +"and provide consistent error messages for the common errors that can be " +"encountered by a great many of programs." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:208 +msgid "First, here is an example that does not use libc error messages:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:215 +#, no-wrap +msgid "" +"#include err.h\n" +"...\n" +"if (!S_ISDIR(st.st_mode))\n" +"\terrx(1, \"argument is not a directory\");\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:218 +msgid "" +"This can be transformed to print an error message by reading `errno` and " +"printing an error message accordingly:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:228 +#, no-wrap +msgid "" +"#include err.h\n" +"#include errno.h\n" +"...\n" +"if (!S_ISDIR(st.st_mode)) {\n" +"\terrno = ENOTDIR;\n" +"\terr(1, NULL);\n" +"}\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:233 +msgid "" +"In this example, the custom string is eliminated, thus translators will have " +"less work when localizing the program and users will see the usual \"Not a " +"directory\" error message when they encounter this error. This message will " +"probably seem more familiar to them. Please note that it was necessary to " +"include [.filename]#errno.h# in order to directly access `errno`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:235 +msgid "" +"It is worth to note that there are cases when `errno` is set automatically " +"by a preceding call, so it is not necessary to set it explicitly:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:242 +#, no-wrap +msgid "" +"#include err.h\n" +"...\n" +"if ((p = malloc(size)) == NULL)\n" +"\terr(1, NULL);\n" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:245 +#, no-wrap +msgid "Making use of [.filename]#bsd.nls.mk#" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:250 +msgid "" +"Using the catalog files requires few repeatable steps, such as compiling the " +"catalogs and installing them to the proper location. In order to simplify " +"this process even more, [.filename]#bsd.nls.mk# introduces some macros. It " +"is not necessary to include [.filename]#bsd.nls.mk# explicitly, it is pulled " +"in from the common Makefiles, such as [.filename]#bsd.prog.mk# or [." +"filename]#bsd.lib.mk#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:254 +msgid "" +"Usually it is enough to define `NLSNAME`, which should have the catalog name " +"mentioned as the first argument of man:catopen[3] and list the catalog files " +"in `NLS` without their `.msg` extension. Here is an example, which makes it " +"possible to to disable NLS when used with the code examples before. The " +"`WITHOUT_NLS` man:make[1] variable has to be defined in order to build the " +"program without NLS support." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:264 +#, no-wrap +msgid "" +".if !defined(WITHOUT_NLS)\n" +"NLS=\tes_ES.ISO8859-1\n" +"NLS+=\thu_HU.ISO8859-2\n" +"NLS+=\tpt_BR.ISO8859-1\n" +".else\n" +"CFLAGS+=\t-DWITHOUT_NLS\n" +".endif\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/l10n/_index.adoc:271 +msgid "" +"Conventionally, the catalog files are placed under the [.filename]#nls# " +"subdirectory and this is the default behavior of [.filename]#bsd.nls.mk#. " +"It is possible, though to override the location of the catalogs with the " +"`NLSSRCDIR` man:make[1] variable. The default name of the precompiled " +"catalog files also follow the naming convention mentioned before. It can be " +"overridden by setting the `NLSNAME` variable. There are other options to " +"fine tune the processing of the catalog files but usually it is not needed, " +"thus they are not described here. For further information on [." +"filename]#bsd.nls.mk#, please refer to the file itself, it is short and easy " +"to understand." +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/parti.adoc b/documentation/content/en/books/developers-handbook/parti.adoc index c4339b493f..1f36ff7945 100644 --- a/documentation/content/en/books/developers-handbook/parti.adoc +++ b/documentation/content/en/books/developers-handbook/parti.adoc @@ -4,7 +4,7 @@ prev: books/developers-handbook next: books/developers-handbook/introduction showBookMenu: true weight: 1 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/parti/" --- [[basics]] diff --git a/documentation/content/en/books/developers-handbook/parti.po b/documentation/content/en/books/developers-handbook/parti.po new file mode 100644 index 0000000000..2633ca0fc2 --- /dev/null +++ b/documentation/content/en/books/developers-handbook/parti.po @@ -0,0 +1,29 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-01-08 11:34-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/parti.adoc:1 +#, no-wrap +msgid "Part I. Basics" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/parti.adoc:11 +#, no-wrap +msgid "Basics" +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/partii.adoc b/documentation/content/en/books/developers-handbook/partii.adoc index 21b05ff266..51ee82ebbe 100644 --- a/documentation/content/en/books/developers-handbook/partii.adoc +++ b/documentation/content/en/books/developers-handbook/partii.adoc @@ -4,7 +4,7 @@ prev: books/developers-handbook/testing next: books/developers-handbook/sockets showBookMenu: true weight: 8 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/partii/" --- [[ipc]] diff --git a/documentation/content/en/books/developers-handbook/partii.po b/documentation/content/en/books/developers-handbook/partii.po new file mode 100644 index 0000000000..38000c08ae --- /dev/null +++ b/documentation/content/en/books/developers-handbook/partii.po @@ -0,0 +1,29 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-01-08 11:34-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/partii.adoc:1 +#, no-wrap +msgid "Part II. Interprocess Communication" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/partii.adoc:11 +#, no-wrap +msgid "Interprocess Communication" +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/partiii.adoc b/documentation/content/en/books/developers-handbook/partiii.adoc index 2af9e4e133..78849f8149 100644 --- a/documentation/content/en/books/developers-handbook/partiii.adoc +++ b/documentation/content/en/books/developers-handbook/partiii.adoc @@ -4,7 +4,7 @@ prev: books/developers-handbook/ipv6 next: books/developers-handbook/kernelbuild showBookMenu: true weight: 11 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/partiii/" --- [[kernel]] diff --git a/documentation/content/en/books/developers-handbook/partiii.po b/documentation/content/en/books/developers-handbook/partiii.po new file mode 100644 index 0000000000..ae1194a66e --- /dev/null +++ b/documentation/content/en/books/developers-handbook/partiii.po @@ -0,0 +1,29 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-01-08 11:34-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/partiii.adoc:1 +#, no-wrap +msgid "Part III. Kernel" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/partiii.adoc:11 +#, no-wrap +msgid "Kernel" +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/partiv.adoc b/documentation/content/en/books/developers-handbook/partiv.adoc index a577253ab8..8b2993bf88 100644 --- a/documentation/content/en/books/developers-handbook/partiv.adoc +++ b/documentation/content/en/books/developers-handbook/partiv.adoc @@ -4,7 +4,7 @@ prev: books/developers-handbook/kerneldebug next: books/developers-handbook/x86 showBookMenu: true weight: 14 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/partiv/" --- [[architectures]] diff --git a/documentation/content/en/books/developers-handbook/partiv.po b/documentation/content/en/books/developers-handbook/partiv.po new file mode 100644 index 0000000000..9731bd3d63 --- /dev/null +++ b/documentation/content/en/books/developers-handbook/partiv.po @@ -0,0 +1,29 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-01-08 11:34-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/partiv.adoc:1 +#, no-wrap +msgid "Part IV. Architectures" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/partiv.adoc:11 +#, no-wrap +msgid "Architectures" +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/partv.adoc b/documentation/content/en/books/developers-handbook/partv.adoc index 8c1d1474e1..4794f4bd89 100644 --- a/documentation/content/en/books/developers-handbook/partv.adoc +++ b/documentation/content/en/books/developers-handbook/partv.adoc @@ -4,7 +4,7 @@ prev: books/developers-handbook/x86 next: books/developers-handbook/bibliography showBookMenu: true weight: 16 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/partv/" --- [[appendices]] diff --git a/documentation/content/en/books/developers-handbook/partv.po b/documentation/content/en/books/developers-handbook/partv.po new file mode 100644 index 0000000000..c1d910f5c0 --- /dev/null +++ b/documentation/content/en/books/developers-handbook/partv.po @@ -0,0 +1,29 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-01-08 11:34-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/partv.adoc:1 +#, no-wrap +msgid "Part V. Appendices" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/partv.adoc:11 +#, no-wrap +msgid "Appendices" +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/policies/_index.adoc b/documentation/content/en/books/developers-handbook/policies/_index.adoc index 8a82420765..11c72b163b 100644 --- a/documentation/content/en/books/developers-handbook/policies/_index.adoc +++ b/documentation/content/en/books/developers-handbook/policies/_index.adoc @@ -9,7 +9,7 @@ description: Source Tree Guidelines and Policies tags: ["Style Guidelines", "MAINTAINER", "Makefiles", "Contributed Software", "Shared libraries"] showBookMenu: true weight: 6 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/policies/" --- [[policies]] @@ -87,191 +87,28 @@ The role of the maintainer is as follows: Some parts of the FreeBSD distribution consist of software that is actively being maintained outside the FreeBSD project. For historical reasons, we call this _contributed_ software. -Some examples are sendmail, gcc and patch. +Some examples are LLVM, man:zlib[3], and man:awk[1]. -Over the last couple of years, various methods have been used in dealing with this type of software and all have some number of advantages and drawbacks. -No clear winner has emerged. +The accepted procedure for managing contributed software involves creating a _vendor branch_, where the software can be imported cleanly (without modification) and updates can be tracked in a versioned manner. +Then, the content of the vendor branch is applied to the source tree, possibly with local modifications. +FreeBSD-specific build glue is maintained in the source tree, not in the vendor branch. -Since this is the case, after some debate one of these methods has been selected as the "official" method and will be required for future imports of software of this kind. -Furthermore, it is strongly suggested that existing contributed software converge on this model over time, as it has significant advantages over the old method, including the ability to easily obtain diffs relative to the "official" versions of the source by everyone (even without direct repository access). -This will make it significantly easier to return changes to the primary developers of the contributed software. +Depending on their needs and complexity, individual software projects may deviate from this procedure, at the discretion of the maintainer. +The exact steps required to update a particular piece of contributed software should be recorded in a file named `FREEBSD-upgrade`; +for example, link:https://cgit.freebsd.org/src/tree/contrib/libarchive/FREEBSD-upgrade[libarchive's FREEBSD-upgrade file]. -Ultimately, however, it comes down to the people actually doing the work. -If using this model is particularly unsuited to the package being dealt with, exceptions to these rules may be granted only with the approval of the core team and with the general consensus of the other developers. -The ability to maintain the package in the future will be a key issue in the decisions. +Contributed software is usually placed in the [.filepath]#contrib/# subdirectory of the source tree, with some exceptions. +Contributed software used only by the kernel lives under [.filepath]#sys/contrib/#. [NOTE] ==== Because it makes it harder to import future versions minor, trivial and/or cosmetic changes are _strongly discouraged_ on files that are still tracking the vendor branch. ==== -[[vendor-import-svn]] -=== Vendor Imports with SVN - -This section describes the vendor import procedure with Subversion in details. - -[.procedure] -. *Preparing the Tree* -+ -If this is your first import after the switch to SVN, you will have to flatten and clean up the vendor tree, and bootstrap merge history in the main tree. -If not, you can safely omit this step. -+ -During the conversion from CVS to SVN, vendor branches were imported with the same layout as the main tree. -For example, the foo vendor sources ended up in [.filename]#vendor/foo/dist/contrib/foo#, but it is pointless and rather inconvenient. -What we really want is to have the vendor source directly in [.filename]#vendor/foo/dist#, like this: -+ -[source,bash] -.... -% cd vendor/foo/dist/contrib/foo -% svn move $(svn list) ../.. -% cd ../.. -% svn remove contrib -% svn propdel -R svn:mergeinfo -% svn commit -.... -+ -Note that, the `propdel` bit is necessary because starting with 1.5, Subversion will automatically add `svn:mergeinfo` to any directory you copy or move. -In this case, you will not need this information, since you are not going to merge anything from the tree you deleted. -+ -[NOTE] -==== -You may want to flatten the tags as well. -The procedure is exactly the same. -If you do this, put off the commit until the end. -==== -+ -Check the [.filename]#dist# tree and perform any cleanup that is deemed to be necessary. -You may want to disable keyword expansion, as it makes no sense on unmodified vendor code. -In some cases, it can be even be harmful. -+ -[source,bash] -.... -% svn propdel svn:keywords -R . -% svn commit -.... -+ -Bootstrapping of `svn:mergeinfo` on the target directory (in the main tree) to the revision that corresponds to the last change was made to the vendor tree prior to importing new sources is also needed: -+ -[source,bash] -.... -% cd head/contrib/foo -% svn merge --record-only ^/vendor/foo/dist@12345678 . -% svn commit -.... -+ -With some shells, the `^` in the above command may need to be escaped with a backslash. -. *Importing New Sources* -+ -Prepare a full, clean tree of the vendor sources. -With SVN, we can keep a full distribution in the vendor tree without bloating the main tree. -Import everything but merge only what is needed. -+ -Note that you will need to add any files that were added since the last vendor import, and remove any that were removed. -To facilitate this, you should prepare sorted lists of the contents of the vendor tree and of the sources you are about to import: -+ -[source,bash] -.... -% cd vendor/foo/dist -% svn list -R | grep -v '/$' | sort > ../old -% cd ../foo-9.9 -% find . -type f | cut -c 3- | sort > ../new -.... -+ -With these two files, the following command will list removed files (files only in [.filename]#old#): -+ -[source,bash] -.... -% comm -23 ../old ../new -.... -+ -While the command below will list added files (files only in [.filename]#new#): -+ -[source,bash] -.... -% comm -13 ../old ../new -.... -+ -Let us put this together: -+ -[source,bash] -.... -% cd vendor/foo/foo-9.9 -% tar cf - . | tar xf - -C ../dist -% cd ../dist -% comm -23 ../old ../new | xargs svn remove -% comm -13 ../old ../new | xargs svn add -.... -+ -[WARNING] -==== -If there are new directories in the new distribution, the last command will fail. -You will have to add the directories, and run it again. -Conversely, if any directories were removed, you will have to remove them manually. -==== -+ -Check properties on any new files: - -** All text files should have `svn:eol-style` set to `native`. -** All binary files should have `svn:mime-type` set to `application/octet-stream`, unless there is a more appropriate media type. -** Executable files should have `svn:executable` set to `*`. -** There should be no other properties on any file in the tree. -+ -[NOTE] -==== -You are ready to commit, but you should first check the output of `svn stat` and `svn diff` to make sure everything is in order. -==== -+ -Once you have committed the new vendor release, you should tag it for future reference. -The best and quickest way is to do it directly in the repository: -+ -[source,bash] -.... -% svn copy ^/vendor/foo/dist svn_base/vendor/foo/9.9 -.... -+ -To get the new tag, you can update your working copy of [.filename]#vendor/foo#. -+ -[NOTE] -==== -If you choose to do the copy in the checkout instead, do not forget to remove the generated `svn:mergeinfo` as described above. -==== +[[vendor-import]] +=== Vendor Imports -. *Merging to __-HEAD__* -+ -After you have prepared your import, it is time to merge. -Option `--accept=postpone` tells SVN not to handle merge conflicts yet, because they will be taken care of manually: -+ -[source,bash] -.... -% cd head/contrib/foo -% svn update -% svn merge --accept=postpone ^/vendor/foo/dist -.... -+ -Resolve any conflicts, and make sure that any files that were added or removed in the vendor tree have been properly added or removed in the main tree. It is always a good idea to check differences against the vendor branch: -+ -[source,bash] -.... -% svn diff --no-diff-deleted --old=^/vendor/foo/dist --new=. -.... -+ -`--no-diff-deleted` tells SVN not to check files that are in the vendor tree but not in the main tree. -+ -[NOTE] -==== -With SVN, there is no concept of on or off the vendor branch. -If a file that previously had local modifications no longer does, just remove any left-over cruft, such as FreeBSD version tags, -so it no longer shows up in diffs against the vendor tree. -==== -+ -If any changes are required for the world to build with the new sources, make them now - and test until you are satisfied that everything build and runs correctly. -. *Commit* -+ -Now, you are ready to commit. -Make sure you get everything in one go. -Ideally, you would have done all steps in a clean tree, in which case you can just commit from the top of that tree. -That is the best way to avoid surprises. -If you do it properly, the tree will move atomically from a consistent state with the old code to a consistent state with the new code. +The standard process for managing contributed software and vendor branches is described in detail by the extref:{committers-guide}#vendor-import-git[Committer's Guide]. [[policies-encumbered]] == Encumbered Files diff --git a/documentation/content/en/books/developers-handbook/policies/_index.po b/documentation/content/en/books/developers-handbook/policies/_index.po new file mode 100644 index 0000000000..d2a1565eec --- /dev/null +++ b/documentation/content/en/books/developers-handbook/policies/_index.po @@ -0,0 +1,396 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2024-01-17 20:34-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:1 +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:16 +#, no-wrap +msgid "Source Tree Guidelines and Policies" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:1 +#, no-wrap +msgid "Chapter 5. Source Tree Guidelines and Policies" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:54 +msgid "" +"This chapter documents various guidelines and policies in force for the " +"FreeBSD source tree." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:56 +#, no-wrap +msgid "Style Guidelines" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:60 +msgid "" +"Consistent coding style is extremely important, particularly with large " +"projects like FreeBSD. Code should follow the FreeBSD coding styles " +"described in man:style[9] and man:style.Makefile[5]." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:62 +#, no-wrap +msgid "`MAINTAINER` on Makefiles" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:66 +msgid "" +"If a particular portion of the FreeBSD [.filename]#src/# distribution is " +"being maintained by a person or group of persons, this is communicated " +"through an entry in [.filename]#src/MAINTAINERS#. Maintainers of ports " +"within the Ports Collection express their maintainership to the world by " +"adding a `MAINTAINER` line to the [.filename]#Makefile# of the port in " +"question:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:70 +#, no-wrap +msgid "MAINTAINER= email-addresses\n" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:77 +msgid "" +"For other parts of the repository, or for sections not listed as having a " +"maintainer, or when you are unsure who the active maintainer is, try looking " +"at the recent commit history of the relevant parts of the source tree. It " +"is quite often the case that a maintainer is not explicitly named, but the " +"people who are actively working in a part of the source tree for, say, the " +"last couple of years are interested in reviewing changes. Even if this is " +"not specifically mentioned in the documentation or the source itself, asking " +"for a review as a form of courtesy is a very reasonable thing to do." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:80 +msgid "The role of the maintainer is as follows:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:82 +msgid "" +"The maintainer owns and is responsible for that code. This means that he or " +"she is responsible for fixing bugs and answering problem reports pertaining " +"to that piece of the code, and in the case of contributed software, for " +"tracking new versions, as appropriate." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:83 +msgid "" +"Changes to directories which have a maintainer defined shall be sent to the " +"maintainer for review before being committed. Only if the maintainer does " +"not respond for an unacceptable period of time, to several emails, will it " +"be acceptable to commit changes without review by the maintainer. However, " +"it is suggested that you try to have the changes reviewed by someone else if " +"at all possible." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:84 +msgid "" +"It is of course not acceptable to add a person or group as maintainer unless " +"they agree to assume this duty. On the other hand it does not have to be a " +"committer and it can easily be a group of people." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:86 +#, no-wrap +msgid "Contributed Software" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:91 +msgid "" +"Some parts of the FreeBSD distribution consist of software that is actively " +"being maintained outside the FreeBSD project. For historical reasons, we " +"call this _contributed_ software. Some examples are LLVM, man:zlib[3], and " +"man:awk[1]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:95 +msgid "" +"The accepted procedure for managing contributed software involves creating a " +"_vendor branch_, where the software can be imported cleanly (without " +"modification) and updates can be tracked in a versioned manner. Then, the " +"content of the vendor branch is applied to the source tree, possibly with " +"local modifications. FreeBSD-specific build glue is maintained in the " +"source tree, not in the vendor branch." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:99 +msgid "" +"Depending on their needs and complexity, individual software projects may " +"deviate from this procedure, at the discretion of the maintainer. The exact " +"steps required to update a particular piece of contributed software should " +"be recorded in a file named `FREEBSD-upgrade`; for example, link:https://" +"cgit.freebsd.org/src/tree/contrib/libarchive/FREEBSD-upgrade[libarchive's " +"FREEBSD-upgrade file]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:102 +msgid "" +"Contributed software is usually placed in the [.filepath]#contrib/# " +"subdirectory of the source tree, with some exceptions. Contributed software " +"used only by the kernel lives under [.filepath]#sys/contrib/#." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:106 +msgid "" +"Because it makes it harder to import future versions minor, trivial and/or " +"cosmetic changes are _strongly discouraged_ on files that are still tracking " +"the vendor branch." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:109 +#, no-wrap +msgid "Vendor Imports" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:112 +msgid "" +"The standard process for managing contributed software and vendor branches " +"is described in detail by the extref:{committers-guide}#vendor-import-" +"git[Committer's Guide]." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:114 +#, no-wrap +msgid "Encumbered Files" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:120 +msgid "" +"It might occasionally be necessary to include an encumbered file in the " +"FreeBSD source tree. For example, if a device requires a small piece of " +"binary code to be loaded to it before the device will operate, and we do not " +"have the source to that code, then the binary file is said to be " +"encumbered. The following policies apply to including encumbered files in " +"the FreeBSD source tree." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:122 +msgid "" +"Any file which is interpreted or executed by the system CPU(s) and not in " +"source format is encumbered." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:123 +msgid "Any file with a license more restrictive than BSD or GNU is encumbered." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:124 +msgid "" +"A file which contains downloadable binary data for use by the hardware is " +"not encumbered, unless (1) or (2) apply to it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:125 +msgid "" +"Any encumbered file requires specific approval from the link:https://www." +"FreeBSD.org/administration/#t-core[Core Team] before it is added to the " +"repository." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:126 +msgid "" +"Encumbered files go in [.filename]#src/contrib# or [.filename]#src/sys/" +"contrib#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:127 +msgid "" +"The entire module should be kept together. There is no point in splitting " +"it, unless there is code-sharing with non-encumbered code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:129 +msgid "" +"In the past binary files were typically uuencoded, and named [." +"filename]#arch/filename.o.uu#. This is no longer necessary, and binary " +"files may be added to the repository unchanged." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:130 +msgid "Kernel files:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:131 +msgid "" +"Should always be referenced in [.filename]#conf/files.*# (for build " +"simplicity)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:132 +msgid "" +"Should always be in [.filename]#LINT#, but the link:https://www.FreeBSD.org/" +"administration/#t-core[Core Team] decides per case if it should be commented " +"out or not. The link:https://www.FreeBSD.org/administration/#t-core[Core " +"Team] can, of course, change their minds later on." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:133 +msgid "The _Release Engineer_ decides whether or not it goes into the release." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:135 +msgid "User-land files:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:136 +msgid "" +"The link:https://www.FreeBSD.org/administration/#t-core[Core team] decides " +"if the code should be part of `make world`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:137 +msgid "" +"The link:https://www.FreeBSD.org/administration/#t-re[Release Engineering] " +"decides if it goes into the release." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:139 +#, no-wrap +msgid "Shared Libraries" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:143 +msgid "" +"If you are adding shared library support to a port or other piece of " +"software that does not have one, the version numbers should follow these " +"rules. Generally, the resulting numbers will have nothing to do with the " +"release version of the software." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:145 +msgid "For ports:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:147 +msgid "Prefer using the number already selected by upstream" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:148 +msgid "If upstream provides symbol versioning, ensure that we use their script" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:150 +msgid "For the base system:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:152 +msgid "Start library version from 1" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:153 +msgid "It is strongly recommended to add symbol versioning to the new library" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:154 +msgid "" +"If there is an incompatible change, handle it with symbol versioning, " +"maintaining backward ABI compatibility" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:155 +msgid "" +"If this is impossible, or the library does not use symbol versioning, bump " +"the library version" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:156 +msgid "" +"Before even considering bumping library version for symbol-versioned " +"library, consult with Release Engineering team, providing reasons why the " +"change is so important that it should be allowed despite breaking the ABI" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:158 +msgid "" +"For instance, added functions and bugfixes not changing the interfaces are " +"fine, while deleted functions, changed function call syntax, etc. should " +"either provide backward-compat symbols, or will force the major version " +"number to change." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:160 +msgid "" +"It is the duty of the committer making the change to handle library " +"versioning." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/policies/_index.adoc:165 +msgid "" +"The ELF dynamic linker matches library names literally. There is a popular " +"convention where library version is written in the form `libexample.so.x.y`, " +"where x is the major version, and y is minor. Common practice is to set the " +"library' soname (`DT_SONAME` ELF tag) to `libexample.so.x`, and set up " +"symlinks `libexample.so.x->libexample.so.x.y`, `libexample.so->libexample.so." +"x` on library installation for the latest minor version y. Then, since the " +"static linker searches for `libexample.so` when the `-lexample` command line " +"option is specified, objects linked with libexample get a dependency on the " +"right library. Almost all popular build systems use this scheme " +"automatically." +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/secure/_index.adoc b/documentation/content/en/books/developers-handbook/secure/_index.adoc index 8450244ebb..b320e0fad0 100644 --- a/documentation/content/en/books/developers-handbook/secure/_index.adoc +++ b/documentation/content/en/books/developers-handbook/secure/_index.adoc @@ -8,7 +8,7 @@ description: Secure Programming in FreeBSD tags: ["secure programming", "Buffer Overflows", "SetUID issues"] showBookMenu: true weight: 4 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/secure/" --- [[secure]] diff --git a/documentation/content/en/books/developers-handbook/secure/_index.po b/documentation/content/en/books/developers-handbook/secure/_index.po new file mode 100644 index 0000000000..c298451c7b --- /dev/null +++ b/documentation/content/en/books/developers-handbook/secure/_index.po @@ -0,0 +1,624 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-02-01 10:28-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: description +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:1 +#, no-wrap +msgid "Secure Programming in FreeBSD" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:1 +#, no-wrap +msgid "Chapter 3. Secure Programming" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:15 +#, no-wrap +msgid "Secure Programming" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:53 +#, no-wrap +msgid "Synopsis" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:56 +msgid "" +"This chapter describes some of the security issues that have plagued UNIX(R) " +"programmers for decades and some of the new tools available to help " +"programmers avoid writing exploitable code." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:58 +#, no-wrap +msgid "Secure Design Methodology" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:63 +msgid "" +"Writing secure applications takes a very scrutinous and pessimistic outlook " +"on life. Applications should be run with the principle of \"least privilege" +"\" so that no process is ever running with more than the bare minimum access " +"that it needs to accomplish its function. Previously tested code should be " +"reused whenever possible to avoid common mistakes that others may have " +"already fixed." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:67 +msgid "" +"One of the pitfalls of the UNIX(R) environment is how easy it is to make " +"assumptions about the sanity of the environment. Applications should never " +"trust user input (in all its forms), system resources, inter-process " +"communication, or the timing of events. UNIX(R) processes do not execute " +"synchronously so logical operations are rarely atomic." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:69 +#, no-wrap +msgid "Buffer Overflows" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:75 +msgid "" +"Buffer Overflows have been around since the very beginnings of the von " +"Neumann crossref:bibliography[cod,1] architecture. They first gained " +"widespread notoriety in 1988 with the Morris Internet worm. Unfortunately, " +"the same basic attack remains effective today. By far the most common type " +"of buffer overflow attack is based on corrupting the stack." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:84 +msgid "" +"Most modern computer systems use a stack to pass arguments to procedures and " +"to store local variables. A stack is a last in first out (LIFO) buffer in " +"the high memory area of a process image. When a program invokes a function " +"a new \"stack frame\" is created. This stack frame consists of the " +"arguments passed to the function as well as a dynamic amount of local " +"variable space. The \"stack pointer\" is a register that holds the current " +"location of the top of the stack. Since this value is constantly changing " +"as new values are pushed onto the top of the stack, many implementations " +"also provide a \"frame pointer\" that is located near the beginning of a " +"stack frame so that local variables can more easily be addressed relative to " +"this value. crossref:bibliography[cod,1] The return address for function " +"calls is also stored on the stack, and this is the cause of stack-overflow " +"exploits since overflowing a local variable in a function can overwrite the " +"return address of that function, potentially allowing a malicious user to " +"execute any code he or she wants." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:87 +msgid "" +"Although stack-based attacks are by far the most common, it would also be " +"possible to overrun the stack with a heap-based (malloc/free) attack." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:90 +msgid "" +"The C programming language does not perform automatic bounds checking on " +"arrays or pointers as many other languages do. In addition, the standard C " +"library is filled with a handful of very dangerous functions." +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:96 +#, no-wrap +msgid "`strcpy`(char *dest, const char *src)" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:100 +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:105 +#, no-wrap +msgid "May overflow the dest buffer" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:101 +#, no-wrap +msgid "`strcat`(char *dest, const char *src)" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:106 +#, no-wrap +msgid "`getwd`(char *buf)" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:110 +#, no-wrap +msgid "May overflow the buf buffer" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:111 +#, no-wrap +msgid "`gets`(char *s)" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:115 +#, no-wrap +msgid "May overflow the s buffer" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:116 +#, no-wrap +msgid "`[vf]scanf`(const char *format, ...)" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:120 +#, no-wrap +msgid "May overflow its arguments." +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:121 +#, no-wrap +msgid "`realpath`(char *path, char resolved_path[])" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:125 +#, no-wrap +msgid "May overflow the path buffer" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:126 +#, no-wrap +msgid "`[v]sprintf`(char *str, const char *format, ...)" +msgstr "" + +#. type: Table +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:129 +#, no-wrap +msgid "May overflow the str buffer." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:131 +#, no-wrap +msgid "Example Buffer Overflow" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:134 +msgid "" +"The following example code contains a buffer overflow designed to overwrite " +"the return address and skip the instruction immediately following the " +"function call. (Inspired by crossref:bibliography[Phrack,4])" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:138 +#, no-wrap +msgid "#include <stdio.h>\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:143 +#, no-wrap +msgid "" +"void manipulate(char *buffer) {\n" +" char newbuffer[80];\n" +" strcpy(newbuffer,buffer);\n" +"}\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:147 +#, no-wrap +msgid "" +"int main() {\n" +" char ch,buffer[4096];\n" +" int i=0;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:149 +#, no-wrap +msgid " while ((buffer[i++] = getchar()) != '\\n') {};\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:156 +#, no-wrap +msgid "" +" i=1;\n" +" manipulate(buffer);\n" +" i=2;\n" +" printf(\"The value of i is : %d\\n\",i);\n" +" return 0;\n" +"}\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:159 +msgid "" +"Let us examine what the memory image of this process would look like if we " +"were to input 160 spaces into our little program before hitting return." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:163 +msgid "" +"Obviously more malicious input can be devised to execute actual compiled " +"instructions (such as exec(/bin/sh))." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:164 +#, no-wrap +msgid "Avoiding Buffer Overflows" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:174 +msgid "" +"The most straightforward solution to the problem of stack-overflows is to " +"always use length restricted memory and string copy functions. `strncpy` " +"and `strncat` are part of the standard C library. These functions accept a " +"length value as a parameter which should be no larger than the size of the " +"destination buffer. These functions will then copy up to 'length' bytes " +"from the source to the destination. However there are a number of problems " +"with these functions. Neither function guarantees NUL termination if the " +"size of the input buffer is as large as the destination. The length " +"parameter is also used inconsistently between strncpy and strncat so it is " +"easy for programmers to get confused as to their proper usage. There is " +"also a significant performance loss compared to `strcpy` when copying a " +"short string into a large buffer since `strncpy` NUL fills up the size " +"specified." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:177 +msgid "" +"Another memory copy implementation exists to get around these problems. The " +"`strlcpy` and `strlcat` functions guarantee that they will always null " +"terminate the destination string when given a non-zero length argument." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:178 +#, no-wrap +msgid "Compiler based run-time bounds checking" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:182 +msgid "" +"Unfortunately there is still a very large assortment of code in public use " +"which blindly copies memory around without using any of the bounded copy " +"routines we just discussed. Fortunately, there is a way to help prevent " +"such attacks - run-time bounds checking, which is implemented by several C/C+" +"+ compilers." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:185 +msgid "" +"ProPolice is one such compiler feature, and is integrated into man:gcc[1] " +"versions 4.1 and later. It replaces and extends the earlier StackGuard man:" +"gcc[1] extension." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:189 +msgid "" +"ProPolice helps to protect against stack-based buffer overflows and other " +"attacks by laying pseudo-random numbers in key areas of the stack before " +"calling any function. When a function returns, these \"canaries\" are " +"checked and if they are found to have been changed the executable is " +"immediately aborted. Thus any attempt to modify the return address or other " +"variable stored on the stack in an attempt to get malicious code to run is " +"unlikely to succeed, as the attacker would have to also manage to leave the " +"pseudo-random canaries untouched." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:191 +msgid "" +"Recompiling your application with ProPolice is an effective means of " +"stopping most buffer-overflow attacks, but it can still be compromised." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:192 +#, no-wrap +msgid "Library based run-time bounds checking" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:196 +msgid "" +"Compiler-based mechanisms are completely useless for binary-only software " +"for which you cannot recompile. For these situations there are a number of " +"libraries which re-implement the unsafe functions of the C-library " +"(`strcpy`, `fscanf`, `getwd`, etc..) and ensure that these functions can " +"never write past the stack pointer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:198 +msgid "libsafe" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:199 +msgid "libverify" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:200 +msgid "libparanoia" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:205 +msgid "" +"Unfortunately these library-based defenses have a number of shortcomings. " +"These libraries only protect against a very small set of security related " +"issues and they neglect to fix the actual problem. These defenses may fail " +"if the application was compiled with -fomit-frame-pointer. Also, the " +"LD_PRELOAD and LD_LIBRARY_PATH environment variables can be overwritten/" +"unset by the user." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:207 +#, no-wrap +msgid "SetUID issues" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:211 +msgid "" +"There are at least 6 different IDs associated with any given process, and " +"you must therefore be very careful with the access that your process has at " +"any given time. In particular, all seteuid applications should give up " +"their privileges as soon as it is no longer required." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:214 +msgid "" +"The real user ID can only be changed by a superuser process. The login " +"program sets this when a user initially logs in and it is seldom changed." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:218 +msgid "" +"The effective user ID is set by the `exec()` functions if a program has its " +"seteuid bit set. An application can call `seteuid()` at any time to set the " +"effective user ID to either the real user ID or the saved set-user-ID. When " +"the effective user ID is set by `exec()` functions, the previous value is " +"saved in the saved set-user-ID." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:220 +#, no-wrap +msgid "Limiting your program's environment" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:228 +msgid "" +"The traditional method of restricting a process is with the `chroot()` " +"system call. This system call changes the root directory from which all " +"other paths are referenced for a process and any child processes. For this " +"call to succeed the process must have execute (search) permission on the " +"directory being referenced. The new environment does not actually take " +"effect until you `chdir()` into your new environment. It should also be " +"noted that a process can easily break out of a chroot environment if it has " +"root privilege. This could be accomplished by creating device nodes to read " +"kernel memory, attaching a debugger to a process outside of the man:" +"chroot[8] environment, or in many other creative ways." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:233 +msgid "" +"The behavior of the `chroot()` system call can be controlled somewhat with " +"the kern.chroot_allow_open_directories `sysctl` variable. When this value " +"is set to 0, `chroot()` will fail with EPERM if there are any directories " +"open. If set to the default value of 1, then `chroot()` will fail with " +"EPERM if there are any directories open and the process is already subject " +"to a `chroot()` call. For any other value, the check for open directories " +"will be bypassed completely." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:234 +#, no-wrap +msgid "FreeBSD's jail functionality" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:238 +msgid "" +"The concept of a Jail extends upon the `chroot()` by limiting the powers of " +"the superuser to create a true `virtual server'. Once a prison is set up " +"all network communication must take place through the specified IP address, " +"and the power of \"root privilege\" in this jail is severely constrained." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:242 +msgid "" +"While in a prison, any tests of superuser power within the kernel using the " +"`suser()` call will fail. However, some calls to `suser()` have been " +"changed to a new interface `suser_xxx()`. This function is responsible for " +"recognizing or denying access to superuser power for imprisoned processes." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:244 +msgid "A superuser process within a jailed environment has the power to:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:246 +msgid "" +"Manipulate credential with `setuid`, `seteuid`, `setgid`, `setegid`, " +"`setgroups`, `setreuid`, `setregid`, `setlogin`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:247 +msgid "Set resource limits with `setrlimit`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:248 +msgid "Modify some sysctl nodes (kern.hostname)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:249 +msgid "`chroot()`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:250 +msgid "Set flags on a vnode: `chflags`, `fchflags`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:251 +msgid "" +"Set attributes of a vnode such as file permission, owner, group, size, " +"access time, and modification time." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:252 +msgid "Bind to privileged ports in the Internet domain (ports < 1024)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:256 +msgid "" +"`Jail` is a very useful tool for running applications in a secure " +"environment but it does have some shortcomings. Currently, the IPC " +"mechanisms have not been converted to the `suser_xxx` so applications such " +"as MySQL cannot be run within a jail. Superuser access may have a very " +"limited meaning within a jail, but there is no way to specify exactly what " +"\"very limited\" means." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:257 +#, no-wrap +msgid "POSIX(R).1e Process Capabilities" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:260 +msgid "" +"POSIX(R) has released a working draft that adds event auditing, access " +"control lists, fine grained privileges, information labeling, and mandatory " +"access control." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:263 +msgid "" +"This is a work in progress and is the focus of the http://www.trustedbsd.org/" +"[TrustedBSD] project. Some of the initial work has been committed to " +"FreeBSD-CURRENT (cap_set_proc(3))." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:265 +#, no-wrap +msgid "Trust" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:269 +msgid "" +"An application should never assume that anything about the users environment " +"is sane. This includes (but is certainly not limited to): user input, " +"signals, environment variables, resources, IPC, mmaps, the filesystem " +"working directory, file descriptors, the # of open files, etc." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:274 +msgid "" +"You should never assume that you can catch all forms of invalid input that a " +"user might supply. Instead, your application should use positive filtering " +"to only allow a specific subset of inputs that you deem safe. Improper data " +"validation has been the cause of many exploits, especially with CGI scripts " +"on the world wide web. For filenames you need to be extra careful about " +"paths (\"../\", \"/\"), symbolic links, and shell escape characters." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:277 +msgid "" +"Perl has a really cool feature called \"Taint\" mode which can be used to " +"prevent scripts from using data derived outside the program in an unsafe " +"way. This mode will check command line arguments, environment variables, " +"locale information, the results of certain syscalls (`readdir()`, " +"`readlink()`, `getpwxxx()`), and all file input." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:279 +#, no-wrap +msgid "Race Conditions" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:283 +msgid "" +"A race condition is anomalous behavior caused by the unexpected dependence " +"on the relative timing of events. In other words, a programmer incorrectly " +"assumed that a particular event would always happen before another." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/secure/_index.adoc:289 +msgid "" +"Some of the common causes of race conditions are signals, access checks, and " +"file opens. Signals are asynchronous events by nature so special care must " +"be taken in dealing with them. Checking access with `access(2)` then " +"`open(2)` is clearly non-atomic. Users can move files in between the two " +"calls. Instead, privileged applications should `seteuid()` and then call " +"`open()` directly. Along the same lines, an application should always set a " +"proper umask before `open()` to obviate the need for spurious `chmod()` " +"calls." +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/sockets/_index.adoc b/documentation/content/en/books/developers-handbook/sockets/_index.adoc index 640f4524da..1a4d4cd522 100644 --- a/documentation/content/en/books/developers-handbook/sockets/_index.adoc +++ b/documentation/content/en/books/developers-handbook/sockets/_index.adoc @@ -8,7 +8,7 @@ description: FreeBSD Sockets tags: ["Sockets", "Protocols"] showBookMenu: true weight: 9 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/sockets/" --- [[sockets]] @@ -559,6 +559,7 @@ We now know enough to write a very simple client, one that will get current time #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> +#include <unistd.h> int main() { register int s; diff --git a/documentation/content/en/books/developers-handbook/sockets/_index.po b/documentation/content/en/books/developers-handbook/sockets/_index.po new file mode 100644 index 0000000000..f09822ceaa --- /dev/null +++ b/documentation/content/en/books/developers-handbook/sockets/_index.po @@ -0,0 +1,2247 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2023-04-20 20:56-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: description +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1 +#, no-wrap +msgid "FreeBSD Sockets" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1 +#, no-wrap +msgid "Chapter 7. Sockets" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:15 +#, no-wrap +msgid "Sockets" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:53 +#, no-wrap +msgid "Synopsis" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:58 +msgid "" +"BSD sockets take interprocess communications to a new level. It is no " +"longer necessary for the communicating processes to run on the same " +"machine. They still _can_, but they do not have to." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:61 +msgid "" +"Not only do these processes not have to run on the same machine, they do not " +"have to run under the same operating system. Thanks to BSD sockets, your " +"FreeBSD software can smoothly cooperate with a program running on a " +"Macintosh(R), another one running on a Sun(TM) workstation, yet another one " +"running under Windows(R) 2000, all connected with an Ethernet-based local " +"area network." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:63 +msgid "" +"But your software can equally well cooperate with processes running in " +"another building, or on another continent, inside a submarine, or a space " +"shuttle." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:66 +msgid "" +"It can also cooperate with processes that are not part of a computer (at " +"least not in the strict sense of the word), but of such devices as printers, " +"digital cameras, medical equipment. Just about anything capable of digital " +"communications." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:68 +#, no-wrap +msgid "Networking and Diversity" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:74 +msgid "" +"We have already hinted on the _diversity_ of networking. Many different " +"systems have to talk to each other. And they have to speak the same " +"language. They also have to _understand_ the same language the same way." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:79 +msgid "" +"People often think that _body language_ is universal. But it is not. Back " +"in my early teens, my father took me to Bulgaria. We were sitting at a " +"table in a park in Sofia, when a vendor approached us trying to sell us some " +"roasted almonds." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:82 +msgid "" +"I had not learned much Bulgarian by then, so, instead of saying no, I shook " +"my head from side to side, the \"universal\" body language for _no_. The " +"vendor quickly started serving us some almonds." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:90 +msgid "" +"I then remembered I had been told that in Bulgaria shaking your head " +"sideways meant _yes_. Quickly, I started nodding my head up and down. The " +"vendor noticed, took his almonds, and walked away. To an uninformed " +"observer, I did not change the body language: I continued using the language " +"of shaking and nodding my head. What changed was the _meaning_ of the body " +"language. At first, the vendor and I interpreted the same language as " +"having completely different meaning. I had to adjust my own interpretation " +"of that language so the vendor would understand." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:94 +msgid "" +"It is the same with computers: The same symbols may have different, even " +"outright opposite meaning. Therefore, for two computers to understand each " +"other, they must not only agree on the same _language_, but on the same " +"_interpretation_ of the language." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:96 +#, no-wrap +msgid "Protocols" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:103 +msgid "" +"While various programming languages tend to have complex syntax and use a " +"number of multi-letter reserved words (which makes them easy for the human " +"programmer to understand), the languages of data communications tend to be " +"very terse. Instead of multi-byte words, they often use individual _bits_. " +"There is a very convincing reason for it: While data travels _inside_ your " +"computer at speeds approaching the speed of light, it often travels " +"considerably slower between two computers." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:105 +msgid "" +"As the languages used in data communications are so terse, we usually refer " +"to them as _protocols_ rather than languages." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:110 +msgid "" +"As data travels from one computer to another, it always uses more than one " +"protocol. These protocols are _layered_. The data can be compared to the " +"inside of an onion: You have to peel off several layers of \"skin\" to get " +"to the data. This is best illustrated with a picture:" +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:111 +#, no-wrap +msgid "Protocol Layers" +msgstr "" + +#. type: Target for macro image +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:112 +#, no-wrap +msgid "layers.png" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:115 +msgid "" +"In this example, we are trying to get an image from a web page we are " +"connected to via an Ethernet." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:118 +msgid "" +"The image consists of raw data, which is simply a sequence of RGB values " +"that our software can process, i.e., convert into an image and display on " +"our monitor." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:123 +msgid "" +"Alas, our software has no way of knowing how the raw data is organized: Is " +"it a sequence of RGB values, or a sequence of grayscale intensities, or " +"perhaps of CMYK encoded colors? Is the data represented by 8-bit quanta, or " +"are they 16 bits in size, or perhaps 4 bits? How many rows and columns does " +"the image consist of? Should certain pixels be transparent?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:125 +msgid "I think you get the picture..." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:128 +msgid "" +"To inform our software how to handle the raw data, it is encoded as a PNG " +"file. It could be a GIF, or a JPEG, but it is a PNG." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:130 +msgid "And PNG is a protocol." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:132 +msgid "" +"At this point, I can hear some of you yelling, _\"No, it is not! It is a " +"file format!\"_" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:137 +msgid "" +"Well, of course it is a file format. But from the perspective of data " +"communications, a file format is a protocol: The file structure is a " +"_language_, a terse one at that, communicating to our _process_ how the data " +"is organized. Ergo, it is a _protocol_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:140 +msgid "" +"Alas, if all we received was the PNG file, our software would be facing a " +"serious problem: How is it supposed to know the data is representing an " +"image, as opposed to some text, or perhaps a sound, or what not? Secondly, " +"how is it supposed to know the image is in the PNG format as opposed to GIF, " +"or JPEG, or some other image format?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:144 +msgid "" +"To obtain that information, we are using another protocol: HTTP. This " +"protocol can tell us exactly that the data represents an image, and that it " +"uses the PNG protocol. It can also tell us some other things, but let us " +"stay focused on protocol layers here." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:147 +msgid "" +"So, now we have some data wrapped in the PNG protocol, wrapped in the HTTP " +"protocol. How did we get it from the server?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:151 +msgid "" +"By using TCP/IP over Ethernet, that is how. Indeed, that is three more " +"protocols. Instead of continuing inside out, I am now going to talk about " +"Ethernet, simply because it is easier to explain the rest that way." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:155 +msgid "" +"Ethernet is an interesting system of connecting computers in a _local area " +"network_ (LAN). Each computer has a _network interface card_ (NIC), which " +"has a unique 48-bit ID called its _address_. No two Ethernet NICs in the " +"world have the same address." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:161 +msgid "" +"These NICs are all connected with each other. Whenever one computer wants " +"to communicate with another in the same Ethernet LAN, it sends a message " +"over the network. Every NIC sees the message. But as part of the Ethernet " +"_protocol_, the data contains the address of the destination NIC (among " +"other things). So, only one of all the network interface cards will pay " +"attention to it, the rest will ignore it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:165 +msgid "" +"But not all computers are connected to the same network. Just because we " +"have received the data over our Ethernet does not mean it originated in our " +"own local area network. It could have come to us from some other network " +"(which may not even be Ethernet based) connected with our own network via " +"the Internet." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:169 +msgid "" +"All data is transferred over the Internet using IP, which stands for " +"_Internet Protocol_. Its basic role is to let us know where in the world " +"the data has arrived from, and where it is supposed to go to. It does not " +"_guarantee_ we will receive the data, only that we will know where it came " +"from _if_ we do receive it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:172 +msgid "" +"Even if we do receive the data, IP does not guarantee we will receive " +"various chunks of data in the same order the other computer has sent it to " +"us. So, we can receive the center of our image before we receive the upper " +"left corner and after the lower right, for example." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:174 +msgid "" +"It is TCP (_Transmission Control Protocol_) that asks the sender to resend " +"any lost data and that places it all into the proper order." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:177 +msgid "" +"All in all, it took _five_ different protocols for one computer to " +"communicate to another what an image looks like. We received the data " +"wrapped into the PNG protocol, which was wrapped into the HTTP protocol, " +"which was wrapped into the TCP protocol, which was wrapped into the IP " +"protocol, which was wrapped into the Ethernet protocol." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:181 +msgid "" +"Oh, and by the way, there probably were several other protocols involved " +"somewhere on the way. For example, if our LAN was connected to the Internet " +"through a dial-up call, it used the PPP protocol over the modem which used " +"one (or several) of the various modem protocols, et cetera, et cetera, et " +"cetera..." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:183 +msgid "" +"As a developer you should be asking by now, _\"How am I supposed to handle " +"it all?\"_" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:188 +msgid "" +"Luckily for you, you are _not_ supposed to handle it all. You _are_ " +"supposed to handle some of it, but not all of it. Specifically, you need " +"not worry about the physical connection (in our case Ethernet and possibly " +"PPP, etc). Nor do you need to handle the Internet Protocol, or the " +"Transmission Control Protocol." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:191 +msgid "" +"In other words, you do not have to do anything to receive the data from the " +"other computer. Well, you do have to _ask_ for it, but that is almost as " +"simple as opening a file." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:194 +msgid "" +"Once you have received the data, it is up to you to figure out what to do " +"with it. In our case, you would need to understand the HTTP protocol and " +"the PNG file structure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:198 +msgid "" +"To use an analogy, all the internetworking protocols become a gray area: Not " +"so much because we do not understand how it works, but because we are no " +"longer concerned about it. The sockets interface takes care of this gray " +"area for us:" +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:199 +#, no-wrap +msgid "Sockets Covered Protocol Layers" +msgstr "" + +#. type: Target for macro image +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:200 +#, no-wrap +msgid "slayers.png" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:203 +msgid "" +"We only need to understand any protocols that tell us how to _interpret the " +"data_, not how to _receive_ it from another process, nor how to _send_ it to " +"another process." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:205 +#, no-wrap +msgid "The Sockets Model" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:210 +msgid "" +"BSD sockets are built on the basic UNIX(R) model: _Everything is a file._ In " +"our example, then, sockets would let us receive an _HTTP file_, so to " +"speak. It would then be up to us to extract the _PNG file_ from it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:213 +msgid "" +"Due to the complexity of internetworking, we cannot just use the `open` " +"system call, or the `open()` C function. Instead, we need to take several " +"steps to \"opening\" a socket." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:216 +msgid "" +"Once we do, however, we can start treating the _socket_ the same way we " +"treat any _file descriptor_: We can `read` from it, `write` to it, `pipe` " +"it, and, eventually, `close` it." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:218 +#, no-wrap +msgid "Essential Socket Functions" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:222 +msgid "" +"While FreeBSD offers different functions to work with sockets, we only " +"_need_ four to \"open\" a socket. And in some cases we only need two." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:224 +#, no-wrap +msgid "The Client-Server Difference" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:227 +msgid "" +"Typically, one of the ends of a socket-based data communication is a " +"_server_, the other is a _client_." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:229 +#, no-wrap +msgid "The Common Elements" +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:232 +#, no-wrap +msgid "`socket`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:236 +msgid "" +"The one function used by both, clients and servers, is man:socket[2]. It is " +"declared this way:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:240 +#, no-wrap +msgid "int socket(int domain, int type, int protocol);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:245 +msgid "" +"The return value is of the same type as that of `open`, an integer. FreeBSD " +"allocates its value from the same pool as that of file handles. That is " +"what allows sockets to be treated the same way as files." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:249 +msgid "" +"The `domain` argument tells the system what _protocol family_ you want it to " +"use. Many of them exist, some are vendor specific, others are very common. " +"They are declared in [.filename]#sys/socket.h#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:251 +msgid "Use `PF_INET` for UDP, TCP and other Internet protocols (IPv4)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:255 +msgid "" +"Five values are defined for the `type` argument, again, in [.filename]#sys/" +"socket.h#. All of them start with \"`SOCK_`\". The most common one is " +"`SOCK_STREAM`, which tells the system you are asking for a _reliable stream " +"delivery service_ (which is TCP when used with `PF_INET`)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:257 +msgid "" +"If you asked for `SOCK_DGRAM`, you would be requesting a _connectionless " +"datagram delivery service_ (in our case, UDP)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:259 +msgid "" +"If you wanted to be in charge of the low-level protocols (such as IP), or " +"even network interfaces (e.g., the Ethernet), you would need to specify " +"`SOCK_RAW`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:262 +msgid "" +"Finally, the `protocol` argument depends on the previous two arguments, and " +"is not always meaningful. In that case, use `0` for its value." +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:264 +#, no-wrap +msgid "The Unconnected Socket" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:268 +msgid "" +"Nowhere, in the `socket` function have we specified to what other system we " +"should be connected. Our newly created socket remains _unconnected_." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:271 +msgid "" +"This is on purpose: To use a telephone analogy, we have just attached a " +"modem to the phone line. We have neither told the modem to make a call, nor " +"to answer if the phone rings." +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:274 +#, no-wrap +msgid "`sockaddr`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:279 +msgid "" +"Various functions of the sockets family expect the address of (or pointer " +"to, to use C terminology) a small area of the memory. The various C " +"declarations in the [.filename]#sys/socket.h# refer to it as `struct " +"sockaddr`. This structure is declared in the same file:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:292 +#, no-wrap +msgid "" +"/*\n" +" * Structure used by kernel to store most\n" +" * addresses.\n" +" */\n" +"struct sockaddr {\n" +"\tunsigned char\tsa_len;\t\t/* total length */\n" +"\tsa_family_t\tsa_family;\t/* address family */\n" +"\tchar\t\tsa_data[14];\t/* actually longer; address value */\n" +"};\n" +"#define\tSOCK_MAXADDRLEN\t255\t\t/* longest possible addresses */\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:296 +msgid "" +"Please note the _vagueness_ with which the `sa_data` field is declared, just " +"as an array of `14` bytes, with the comment hinting there can be more than " +"`14` of them." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:299 +msgid "" +"This vagueness is quite deliberate. Sockets is a very powerful interface. " +"While most people perhaps think of it as nothing more than the Internet " +"interface-and most applications probably use it for that nowadays-sockets " +"can be used for just about _any_ kind of interprocess communications, of " +"which the Internet (or, more precisely, IP) is only one." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:302 +msgid "" +"The [.filename]#sys/socket.h# refers to the various types of protocols " +"sockets will handle as _address families_, and lists them right before the " +"definition of `sockaddr`:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:351 +#, no-wrap +msgid "" +"/*\n" +" * Address families.\n" +" */\n" +"#define\tAF_UNSPEC\t0\t\t/* unspecified */\n" +"#define\tAF_LOCAL\t1\t\t/* local to host (pipes, portals) */\n" +"#define\tAF_UNIX\t\tAF_LOCAL\t/* backward compatibility */\n" +"#define\tAF_INET\t\t2\t\t/* internetwork: UDP, TCP, etc. */\n" +"#define\tAF_IMPLINK\t3\t\t/* arpanet imp addresses */\n" +"#define\tAF_PUP\t\t4\t\t/* pup protocols: e.g. BSP */\n" +"#define\tAF_CHAOS\t5\t\t/* mit CHAOS protocols */\n" +"#define\tAF_NS\t\t6\t\t/* XEROX NS protocols */\n" +"#define\tAF_ISO\t\t7\t\t/* ISO protocols */\n" +"#define\tAF_OSI\t\tAF_ISO\n" +"#define\tAF_ECMA\t\t8\t\t/* European computer manufacturers */\n" +"#define\tAF_DATAKIT\t9\t\t/* datakit protocols */\n" +"#define\tAF_CCITT\t10\t\t/* CCITT protocols, X.25 etc */\n" +"#define\tAF_SNA\t\t11\t\t/* IBM SNA */\n" +"#define AF_DECnet\t12\t\t/* DECnet */\n" +"#define AF_DLI\t\t13\t\t/* DEC Direct data link interface */\n" +"#define AF_LAT\t\t14\t\t/* LAT */\n" +"#define\tAF_HYLINK\t15\t\t/* NSC Hyperchannel */\n" +"#define\tAF_APPLETALK\t16\t\t/* Apple Talk */\n" +"#define\tAF_ROUTE\t17\t\t/* Internal Routing Protocol */\n" +"#define\tAF_LINK\t\t18\t\t/* Link layer interface */\n" +"#define\tpseudo_AF_XTP\t19\t\t/* eXpress Transfer Protocol (no AF) */\n" +"#define\tAF_COIP\t\t20\t\t/* connection-oriented IP, aka ST II */\n" +"#define\tAF_CNT\t\t21\t\t/* Computer Network Technology */\n" +"#define pseudo_AF_RTIP\t22\t\t/* Help Identify RTIP packets */\n" +"#define\tAF_IPX\t\t23\t\t/* Novell Internet Protocol */\n" +"#define\tAF_SIP\t\t24\t\t/* Simple Internet Protocol */\n" +"#define\tpseudo_AF_PIP\t25\t\t/* Help Identify PIP packets */\n" +"#define\tAF_ISDN\t\t26\t\t/* Integrated Services Digital Network*/\n" +"#define\tAF_E164\t\tAF_ISDN\t\t/* CCITT E.164 recommendation */\n" +"#define\tpseudo_AF_KEY\t27\t\t/* Internal key-management function */\n" +"#define\tAF_INET6\t28\t\t/* IPv6 */\n" +"#define\tAF_NATM\t\t29\t\t/* native ATM access */\n" +"#define\tAF_ATM\t\t30\t\t/* ATM */\n" +"#define pseudo_AF_HDRCMPLT 31\t\t/* Used by BPF to not rewrite headers\n" +"\t\t\t\t\t * in interface output routine\n" +"\t\t\t\t\t */\n" +"#define\tAF_NETGRAPH\t32\t\t/* Netgraph sockets */\n" +"#define\tAF_SLOW\t\t33\t\t/* 802.3ad slow protocol */\n" +"#define\tAF_SCLUSTER\t34\t\t/* Sitara cluster protocol */\n" +"#define\tAF_ARP\t\t35\n" +"#define\tAF_BLUETOOTH\t36\t\t/* Bluetooth sockets */\n" +"#define\tAF_MAX\t\t37\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:355 +msgid "The one used for IP is AF_INET. It is a symbol for the constant `2`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:357 +msgid "" +"It is the _address family_ listed in the `sa_family` field of `sockaddr` " +"that decides how exactly the vaguely named bytes of `sa_data` will be used." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:359 +msgid "" +"Specifically, whenever the _address family_ is AF_INET, we can use `struct " +"sockaddr_in` found in [.filename]#netinet/in.h#, wherever `sockaddr` is " +"expected:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:372 +#, no-wrap +msgid "" +"/*\n" +" * Socket address, internet style.\n" +" */\n" +"struct sockaddr_in {\n" +"\tuint8_t\t\tsin_len;\n" +"\tsa_family_t\tsin_family;\n" +"\tin_port_t\tsin_port;\n" +"\tstruct\tin_addr sin_addr;\n" +"\tchar\tsin_zero[8];\n" +"};\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:375 +msgid "We can visualize its organization this way:" +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:376 +#, no-wrap +msgid "sockaddr_in structure" +msgstr "" + +#. type: Target for macro image +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:377 +#, no-wrap +msgid "sain.png" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:380 +msgid "" +"The three important fields are `sin_family`, which is byte 1 of the " +"structure, `sin_port`, a 16-bit value found in bytes 2 and 3, and " +"`sin_addr`, a 32-bit integer representation of the IP address, stored in " +"bytes 4-7." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:386 +msgid "" +"Now, let us try to fill it out. Let us assume we are trying to write a " +"client for the _daytime_ protocol, which simply states that its server will " +"write a text string representing the current date and time to port 13. We " +"want to use TCP/IP, so we need to specify `AF_INET` in the address family " +"field. `AF_INET` is defined as `2`. Let us use the IP address of " +"`192.43.244.18`, which is the time server of US federal government (`time." +"nist.gov`)." +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:387 +#, no-wrap +msgid "Specific example of sockaddr_in" +msgstr "" + +#. type: Target for macro image +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:388 +#, no-wrap +msgid "sainfill.png" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:391 +msgid "" +"By the way the `sin_addr` field is declared as being of the `struct in_addr` " +"type, which is defined in [.filename]#netinet/in.h#:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:400 +#, no-wrap +msgid "" +"/*\n" +" * Internet address (a structure for historical reasons)\n" +" */\n" +"struct in_addr {\n" +"\tin_addr_t s_addr;\n" +"};\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:403 +msgid "In addition, `in_addr_t` is a 32-bit integer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:405 +msgid "" +"The `192.43.244.18` is just a convenient notation of expressing a 32-bit " +"integer by listing all of its 8-bit bytes, starting with the _most " +"significant_ one." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:409 +msgid "" +"So far, we have viewed `sockaddr` as an abstraction. Our computer does not " +"store `short` integers as a single 16-bit entity, but as a sequence of 2 " +"bytes. Similarly, it stores 32-bit integers as a sequence of 4 bytes." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:411 +msgid "Suppose we coded something like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:417 +#, no-wrap +msgid "" +"sa.sin_family = AF_INET;\n" +"sa.sin_port = 13;\n" +"sa.sin_addr.s_addr = (((((192 << 8) | 43) << 8) | 244) << 8) | 18;\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:420 +msgid "What would the result look like?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:423 +msgid "" +"Well, that depends, of course. On a Pentium(R), or other x86, based " +"computer, it would look like this:" +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:424 +#, no-wrap +msgid "sockaddr_in on an Intel system" +msgstr "" + +#. type: Target for macro image +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:425 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:471 +#, no-wrap +msgid "sainlsb.png" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:428 +msgid "On a different system, it might look like this:" +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:429 +#, no-wrap +msgid "sockaddr_in on an MSB system" +msgstr "" + +#. type: Target for macro image +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:430 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:476 +#, no-wrap +msgid "sainmsb.png" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:434 +msgid "" +"And on a PDP it might look different yet. But the above two are the most " +"common ways in use today." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:438 +msgid "" +"Ordinarily, wanting to write portable code, programmers pretend that these " +"differences do not exist. And they get away with it (except when they code " +"in assembly language). Alas, you cannot get away with it that easily when " +"coding for sockets." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:440 +msgid "Why?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:442 +msgid "" +"Because when communicating with another computer, you usually do not know " +"whether it stores data _most significant byte_ (MSB) or _least significant " +"byte_ (LSB) first." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:444 +msgid "You might be wondering, _\"So, will sockets not handle it for me?\"_" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:446 +msgid "It will not." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:449 +msgid "" +"While that answer may surprise you at first, remember that the general " +"sockets interface only understands the `sa_len` and `sa_family` fields of " +"the `sockaddr` structure. You do not have to worry about the byte order " +"there (of course, on FreeBSD `sa_family` is only 1 byte anyway, but many " +"other UNIX(R) systems do not have `sa_len` and use 2 bytes for `sa_family`, " +"and expect the data in whatever order is native to the computer)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:452 +msgid "" +"But the rest of the data is just `sa_data[14]` as far as sockets goes. " +"Depending on the _address family_, sockets just forwards that data to its " +"destination." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:457 +msgid "" +"Indeed, when we enter a port number, it is because we want the other " +"computer to know what service we are asking for. And, when we are the " +"server, we read the port number so we know what service the other computer " +"is expecting from us. Either way, sockets only has to forward the port " +"number as data. It does not interpret it in any way." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:460 +msgid "" +"Similarly, we enter the IP address to tell everyone on the way where to send " +"our data to. Sockets, again, only forwards it as data." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:462 +msgid "" +"That is why, we (the _programmers_, not the _sockets_) have to distinguish " +"between the byte order used by our computer and a conventional byte order to " +"send the data in to the other computer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:464 +msgid "" +"We will call the byte order our computer uses the _host byte order_, or just " +"the _host order_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:467 +msgid "" +"There is a convention of sending the multi-byte data over IP _MSB first_. " +"This, we will refer to as the _network byte order_, or simply the _network " +"order_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:469 +msgid "" +"Now, if we compiled the above code for an Intel based computer, our _host " +"byte order_ would produce:" +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:470 +#, no-wrap +msgid "Host byte order on an Intel system" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:474 +msgid "But the _network byte order_ requires that we store the data MSB first:" +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:475 +#, no-wrap +msgid "Network byte order" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:479 +msgid "" +"Unfortunately, our _host order_ is the exact opposite of the _network order_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:482 +msgid "" +"We have several ways of dealing with it. One would be to _reverse_ the " +"values in our code:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:488 +#, no-wrap +msgid "" +"sa.sin_family = AF_INET;\n" +"sa.sin_port = 13 << 8;\n" +"sa.sin_addr.s_addr = (((((18 << 8) | 244) << 8) | 43) << 8) | 192;\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:493 +msgid "" +"This will _trick_ our compiler into storing the data in the _network byte " +"order_. In some cases, this is exactly the way to do it (e.g., when " +"programming in assembly language). In most cases, however, it can cause a " +"problem." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:497 +msgid "" +"Suppose, you wrote a sockets-based program in C. You know it is going to " +"run on a Pentium(R), so you enter all your constants in reverse and force " +"them to the _network byte order_. It works well." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:502 +msgid "" +"Then, some day, your trusted old Pentium(R) becomes a rusty old Pentium(R). " +"You replace it with a system whose _host order_ is the same as the _network " +"order_. You need to recompile all your software. All of your software " +"continues to perform well, except the one program you wrote." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:506 +msgid "" +"You have since forgotten that you had forced all of your constants to the " +"opposite of the _host order_. You spend some quality time tearing out your " +"hair, calling the names of all gods you ever heard of (and some you made " +"up), hitting your monitor with a nerf bat, and performing all the other " +"traditional ceremonies of trying to figure out why something that has worked " +"so well is suddenly not working at all." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:508 +msgid "" +"Eventually, you figure it out, say a couple of swear words, and start " +"rewriting your code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:511 +msgid "" +"Luckily, you are not the first one to face the problem. Someone else has " +"created the man:htons[3] and man:htonl[3] C functions to convert a `short` " +"and `long` respectively from the _host byte order_ to the _network byte " +"order_, and the man:ntohs[3] and man:ntohl[3] C functions to go the other " +"way." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:514 +msgid "" +"On _MSB-first_ systems these functions do nothing. On _LSB-first_ systems " +"they convert values to the proper order." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:516 +msgid "" +"So, regardless of what system your software is compiled on, your data will " +"end up in the correct order if you use these functions." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:518 +#, no-wrap +msgid "Client Functions" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:523 +msgid "" +"Typically, the client initiates the connection to the server. The client " +"knows which server it is about to call: It knows its IP address, and it " +"knows the _port_ the server resides at. It is akin to you picking up the " +"phone and dialing the number (the _address_), then, after someone answers, " +"asking for the person in charge of wingdings (the _port_)." +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:525 +#, no-wrap +msgid "`connect`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:528 +msgid "" +"Once a client has created a socket, it needs to connect it to a specific " +"port on a remote system. It uses man:connect[2]:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:532 +#, no-wrap +msgid "int connect(int s, const struct sockaddr *name, socklen_t namelen);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:537 +msgid "" +"The `s` argument is the socket, i.e., the value returned by the `socket` " +"function. The `name` is a pointer to `sockaddr`, the structure we have " +"talked about extensively. Finally, `namelen` informs the system how many " +"bytes are in our `sockaddr` structure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:540 +msgid "" +"If `connect` is successful, it returns `0`. Otherwise it returns `-1` and " +"stores the error code in `errno`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:544 +msgid "" +"There are many reasons why `connect` may fail. For example, with an attempt " +"to an Internet connection, the IP address may not exist, or it may be down, " +"or just too busy, or it may not have a server listening at the specified " +"port. Or it may outright _refuse_ any request for specific code." +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:546 +#, no-wrap +msgid "Our First Client" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:549 +msgid "" +"We now know enough to write a very simple client, one that will get current " +"time from `192.43.244.18` and print it to [.filename]#stdout#." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:563 +#, no-wrap +msgid "" +"/*\n" +" * daytime.c\n" +" *\n" +" * Programmed by G. Adam Stanislav\n" +" */\n" +"#include <stdio.h>\n" +"#include <string.h>\n" +"#include <sys/types.h>\n" +"#include <sys/socket.h>\n" +"#include <netinet/in.h>\n" +"#include <unistd.h>\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:569 +#, no-wrap +msgid "" +"int main() {\n" +" register int s;\n" +" register int bytes;\n" +" struct sockaddr_in sa;\n" +" char buffer[BUFSIZ+1];\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:574 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:996 +#, no-wrap +msgid "" +" if ((s = socket(PF_INET, SOCK_STREAM, 0)) < 0) {\n" +" perror(\"socket\");\n" +" return 1;\n" +" }\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:576 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:998 +#, no-wrap +msgid " bzero(&sa, sizeof sa);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:585 +#, no-wrap +msgid "" +" sa.sin_family = AF_INET;\n" +" sa.sin_port = htons(13);\n" +" sa.sin_addr.s_addr = htonl((((((192 << 8) | 43) << 8) | 244) << 8) | 18);\n" +" if (connect(s, (struct sockaddr *)&sa, sizeof sa) < 0) {\n" +" perror(\"connect\");\n" +" close(s);\n" +" return 2;\n" +" }\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:588 +#, no-wrap +msgid "" +" while ((bytes = read(s, buffer, BUFSIZ)) > 0)\n" +" write(1, buffer, bytes);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:592 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1022 +#, no-wrap +msgid "" +" close(s);\n" +" return 0;\n" +"}\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:595 +msgid "" +"Go ahead, enter it in your editor, save it as [.filename]#daytime.c#, then " +"compile and run it:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:600 +#, no-wrap +msgid "" +"% cc -O3 -o daytime daytime.c\n" +"% ./daytime\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:603 +#, no-wrap +msgid "" +"52079 01-06-19 02:29:25 50 0 1 543.9 UTC(NIST) *\n" +"%\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:607 +msgid "" +"In this case, the date was June 19, 2001, the time was 02:29:25 UTC. " +"Naturally, your results will vary." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:609 +#, no-wrap +msgid "Server Functions" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:615 +msgid "" +"The typical server does not initiate the connection. Instead, it waits for " +"a client to call it and request services. It does not know when the client " +"will call, nor how many clients will call. It may be just sitting there, " +"waiting patiently, one moment, The next moment, it can find itself swamped " +"with requests from a number of clients, all calling in at the same time." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:617 +msgid "The sockets interface offers three basic functions to handle this." +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:619 +#, no-wrap +msgid "`bind`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:622 +msgid "" +"Ports are like extensions to a phone line: After you dial a number, you dial " +"the extension to get to a specific person or department." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:626 +msgid "" +"There are 65535 IP ports, but a server usually processes requests that come " +"in on only one of them. It is like telling the phone room operator that we " +"are now at work and available to answer the phone at a specific extension. " +"We use man:bind[2] to tell sockets which port we want to serve." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:630 +#, no-wrap +msgid "int bind(int s, const struct sockaddr *addr, socklen_t addrlen);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:635 +msgid "" +"Beside specifying the port in `addr`, the server may include its IP " +"address. However, it can just use the symbolic constant INADDR_ANY to " +"indicate it will serve all requests to the specified port regardless of what " +"its IP address is. This symbol, along with several similar ones, is " +"declared in [.filename]#netinet/in.h#" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:639 +#, no-wrap +msgid "#define\tINADDR_ANY\t\t(u_int32_t)0x00000000\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:644 +msgid "" +"Suppose we were writing a server for the _daytime_ protocol over TCP/IP. " +"Recall that it uses port 13. Our `sockaddr_in` structure would look like " +"this:" +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:645 +#, no-wrap +msgid "Example Server sockaddr_in" +msgstr "" + +#. type: Target for macro image +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:646 +#, no-wrap +msgid "sainserv.png" +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:649 +#, no-wrap +msgid "`listen`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:653 +msgid "" +"To continue our office phone analogy, after you have told the phone central " +"operator what extension you will be at, you now walk into your office, and " +"make sure your own phone is plugged in and the ringer is turned on. Plus, " +"you make sure your call waiting is activated, so you can hear the phone ring " +"even while you are talking to someone." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:655 +msgid "The server ensures all of that with the man:listen[2] function." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:659 +#, no-wrap +msgid "int listen(int s, int backlog);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:663 +msgid "" +"In here, the `backlog` variable tells sockets how many incoming requests to " +"accept while you are busy processing the last request. In other words, it " +"determines the maximum size of the queue of pending connections." +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:665 +#, no-wrap +msgid "`accept`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:670 +msgid "" +"After you hear the phone ringing, you accept the call by answering the " +"call. You have now established a connection with your client. This " +"connection remains active until either you or your client hang up." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:672 +msgid "The server accepts the connection by using the man:accept[2] function." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:676 +#, no-wrap +msgid "int accept(int s, struct sockaddr *addr, socklen_t *addrlen);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:680 +msgid "" +"Note that this time `addrlen` is a pointer. This is necessary because in " +"this case it is the socket that fills out `addr`, the `sockaddr_in` " +"structure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:684 +msgid "" +"The return value is an integer. Indeed, the `accept` returns a _new " +"socket_. You will use this new socket to communicate with the client." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:686 +msgid "" +"What happens to the old socket? It continues to listen for more requests " +"(remember the `backlog` variable we passed to `listen`?) until we `close` it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:690 +msgid "" +"Now, the new socket is meant only for communications. It is fully " +"connected. We cannot pass it to `listen` again, trying to accept additional " +"connections." +msgstr "" + +#. type: Title ===== +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:692 +#, no-wrap +msgid "Our First Server" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:696 +msgid "" +"Our first server will be somewhat more complex than our first client was: " +"Not only do we have more sockets functions to use, but we need to write it " +"as a daemon." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:699 +msgid "" +"This is best achieved by creating a _child process_ after binding the port. " +"The main process then exits and returns control to the shell (or whatever " +"program invoked it)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:701 +msgid "" +"The child calls `listen`, then starts an endless loop, which accepts a " +"connection, serves it, and eventually closes its socket." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:717 +#, no-wrap +msgid "" +"/*\n" +" * daytimed - a port 13 server\n" +" *\n" +" * Programmed by G. Adam Stanislav\n" +" * June 19, 2001\n" +" */\n" +"#include <stdio.h>\n" +"#include <string.h>\n" +"#include <time.h>\n" +"#include <unistd.h>\n" +"#include <sys/types.h>\n" +"#include <sys/socket.h>\n" +"#include <netinet/in.h>\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:719 +#, no-wrap +msgid "#define BACKLOG 4\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:727 +#, no-wrap +msgid "" +"int main() {\n" +" register int s, c;\n" +" int b;\n" +" struct sockaddr_in sa;\n" +" time_t t;\n" +" struct tm *tm;\n" +" FILE *client;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:732 +#, no-wrap +msgid "" +" if ((s = socket(PF_INET, SOCK_STREAM, 0)) < 0) {\n" +" perror(\"socket\");\n" +" return 1;\n" +" }\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:734 +#, no-wrap +msgid " bzero(&sa, sizeof sa);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:737 +#, no-wrap +msgid "" +" sa.sin_family = AF_INET;\n" +" sa.sin_port = htons(13);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:740 +#, no-wrap +msgid "" +" if (INADDR_ANY)\n" +" sa.sin_addr.s_addr = htonl(INADDR_ANY);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:745 +#, no-wrap +msgid "" +" if (bind(s, (struct sockaddr *)&sa, sizeof sa) < 0) {\n" +" perror(\"bind\");\n" +" return 2;\n" +" }\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:758 +#, no-wrap +msgid "" +" switch (fork()) {\n" +" case -1:\n" +" perror(\"fork\");\n" +" return 3;\n" +" break;\n" +" default:\n" +" close(s);\n" +" return 0;\n" +" break;\n" +" case 0:\n" +" break;\n" +" }\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:760 +#, no-wrap +msgid " listen(s, BACKLOG);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:763 +#, no-wrap +msgid "" +" for (;;) {\n" +" b = sizeof sa;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:768 +#, no-wrap +msgid "" +" if ((c = accept(s, (struct sockaddr *)&sa, &b)) < 0) {\n" +" perror(\"daytimed accept\");\n" +" return 4;\n" +" }\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:773 +#, no-wrap +msgid "" +" if ((client = fdopen(c, \"w\")) == NULL) {\n" +" perror(\"daytimed fdopen\");\n" +" return 5;\n" +" }\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:776 +#, no-wrap +msgid "" +" if ((t = time(NULL)) < 0) {\n" +" perror(\"daytimed time\");\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:779 +#, no-wrap +msgid "" +" return 6;\n" +" }\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:788 +#, no-wrap +msgid "" +" tm = gmtime(&t);\n" +" fprintf(client, \"%.4i-%.2i-%.2iT%.2i:%.2i:%.2iZ\\n\",\n" +" tm->tm_year + 1900,\n" +" tm->tm_mon + 1,\n" +" tm->tm_mday,\n" +" tm->tm_hour,\n" +" tm->tm_min,\n" +" tm->tm_sec);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:792 +#, no-wrap +msgid "" +" fclose(client);\n" +" }\n" +"}\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:797 +msgid "" +"We start by creating a socket. Then we fill out the `sockaddr_in` structure " +"in `sa`. Note the conditional use of INADDR_ANY:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:802 +#, no-wrap +msgid "" +"if (INADDR_ANY)\n" +" sa.sin_addr.s_addr = htonl(INADDR_ANY);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:809 +msgid "" +"Its value is `0`. Since we have just used `bzero` on the entire structure, " +"it would be redundant to set it to `0` again. But if we port our code to " +"some other system where INADDR_ANY is perhaps not a zero, we need to assign " +"it to `sa.sin_addr.s_addr`. Most modern C compilers are clever enough to " +"notice that INADDR_ANY is a constant. As long as it is a zero, they will " +"optimize the entire conditional statement out of the code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:813 +msgid "" +"After we have called `bind` successfully, we are ready to become a _daemon_: " +"We use `fork` to create a child process. In both, the parent and the child, " +"the `s` variable is our socket. The parent process will not need it, so it " +"calls `close`, then it returns `0` to inform its own parent it had " +"terminated successfully." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:818 +msgid "" +"Meanwhile, the child process continues working in the background. It calls " +"`listen` and sets its backlog to `4`. It does not need a large value here " +"because _daytime_ is not a protocol many clients request all the time, and " +"because it can process each request instantly anyway." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:820 +msgid "" +"Finally, the daemon starts an endless loop, which performs the following " +"steps:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:823 +msgid "" +"Call `accept`. It waits here until a client contacts it. At that point, it " +"receives a new socket, `c`, which it can use to communicate with this " +"particular client." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:824 +msgid "" +"It uses the C function `fdopen` to turn the socket from a low-level _file " +"descriptor_ to a C-style `FILE` pointer. This will allow the use of " +"`fprintf` later on." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:825 +msgid "" +"It checks the time, and prints it in the _ISO 8601_ format to the `client` " +"\"file\". It then uses `fclose` to close the file. That will automatically " +"close the socket as well." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:827 +msgid "We can _generalize_ this, and use it as a model for many other servers:" +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:828 +#, no-wrap +msgid "Sequential Server" +msgstr "" + +#. type: Target for macro image +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:829 +#, no-wrap +msgid "serv.png" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:835 +msgid "" +"This flowchart is good for _sequential servers_, i.e., servers that can " +"serve one client at a time, just as we were able to with our _daytime_ " +"server. This is only possible whenever there is no real \"conversation\" " +"going on between the client and the server: As soon as the server detects a " +"connection to the client, it sends out some data and closes the connection. " +"The entire operation may take nanoseconds, and it is finished." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:838 +msgid "" +"The advantage of this flowchart is that, except for the brief moment after " +"the parent ``fork``s and before it exits, there is always only one _process_ " +"active: Our server does not take up much memory and other system resources." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:842 +msgid "" +"Note that we have added _initialize daemon_ in our flowchart. We did not " +"need to initialize our own daemon, but this is a good place in the flow of " +"the program to set up any `signal` handlers, open any files we may need, etc." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:846 +msgid "" +"Just about everything in the flow chart can be used literally on many " +"different servers. The _serve_ entry is the exception. We think of it as a " +"_\"black box\"_, i.e., something you design specifically for your own " +"server, and just \"plug it into the rest.\"" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:852 +msgid "" +"Not all protocols are that simple. Many receive a request from the client, " +"reply to it, then receive another request from the same client. As a " +"result, they do not know in advance how long they will be serving the " +"client. Such servers usually start a new process for each client. While " +"the new process is serving its client, the daemon can continue listening for " +"more connections." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:855 +msgid "" +"Now, go ahead, save the above source code as [.filename]#daytimed.c# (it is " +"customary to end the names of daemons with the letter `d`). After you have " +"compiled it, try running it:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:861 +#, no-wrap +msgid "" +"% ./daytimed\n" +"bind: Permission denied\n" +"%\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:865 +msgid "" +"What happened here? As you will recall, the _daytime_ protocol uses port " +"13. But all ports below 1024 are reserved to the superuser (otherwise, " +"anyone could start a daemon pretending to serve a commonly used port, while " +"causing a security breach)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:867 +msgid "Try again, this time as the superuser:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:872 +#, no-wrap +msgid "" +"# ./daytimed\n" +"#\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:875 +msgid "What... Nothing? Let us try again:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:879 +#, no-wrap +msgid "# ./daytimed\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:882 +#, no-wrap +msgid "" +"bind: Address already in use\n" +"#\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:887 +msgid "" +"Every port can only be bound by one program at a time. Our first attempt " +"was indeed successful: It started the child daemon and returned quietly. It " +"is still running and will continue to run until you either kill it, or any " +"of its system calls fail, or you reboot the system." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:890 +msgid "" +"Fine, we know it is running in the background. But is it working? How do we " +"know it is a proper _daytime_ server? Simple:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:894 +#, no-wrap +msgid "% telnet localhost 13\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:903 +#, no-wrap +msgid "" +"Trying ::1...\n" +"telnet: connect to address ::1: Connection refused\n" +"Trying 127.0.0.1...\n" +"Connected to localhost.\n" +"Escape character is '^]'.\n" +"2001-06-19T21:04:42Z\n" +"Connection closed by foreign host.\n" +"%\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:908 +msgid "" +"telnet tried the new IPv6, and failed. It retried with IPv4 and succeeded. " +"The daemon works." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:911 +msgid "" +"If you have access to another UNIX(R) system via telnet, you can use it to " +"test accessing the server remotely. My computer does not have a static IP " +"address, so this is what I did:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:915 +#, no-wrap +msgid "% who\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:919 +#, no-wrap +msgid "" +"whizkid ttyp0 Jun 19 16:59 (216.127.220.143)\n" +"xxx ttyp1 Jun 19 16:06 (xx.xx.xx.xx)\n" +"% telnet 216.127.220.143 13\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:926 +#, no-wrap +msgid "" +"Trying 216.127.220.143...\n" +"Connected to r47.bfm.org.\n" +"Escape character is '^]'.\n" +"2001-06-19T21:31:11Z\n" +"Connection closed by foreign host.\n" +"%\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:929 +msgid "Again, it worked. Will it work using the domain name?" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:933 +#, no-wrap +msgid "% telnet r47.bfm.org 13\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:940 +#, no-wrap +msgid "" +"Trying 216.127.220.143...\n" +"Connected to r47.bfm.org.\n" +"Escape character is '^]'.\n" +"2001-06-19T21:31:40Z\n" +"Connection closed by foreign host.\n" +"%\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:944 +msgid "" +"By the way, telnet prints the _Connection closed by foreign host_ message " +"after our daemon has closed the socket. This shows us that, indeed, using " +"`fclose(client);` in our code works as advertised." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:946 +#, no-wrap +msgid "Helper Functions" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:952 +msgid "" +"FreeBSD C library contains many helper functions for sockets programming. " +"For example, in our sample client we hard coded the `time.nist.gov` IP " +"address. But we do not always know the IP address. Even if we do, our " +"software is more flexible if it allows the user to enter the IP address, or " +"even the domain name." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:954 +#, no-wrap +msgid "`gethostbyname`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:957 +msgid "" +"While there is no way to pass the domain name directly to any of the sockets " +"functions, the FreeBSD C library comes with the man:gethostbyname[3] and man:" +"gethostbyname2[3] functions, declared in [.filename]#netdb.h#." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:962 +#, no-wrap +msgid "" +"struct hostent * gethostbyname(const char *name);\n" +"struct hostent * gethostbyname2(const char *name, int af);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:966 +msgid "" +"Both return a pointer to the `hostent` structure, with much information " +"about the domain. For our purposes, the `h_addr_list[0]` field of the " +"structure points at `h_length` bytes of the correct address, already stored " +"in the _network byte order_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:968 +msgid "" +"This allows us to create a much more flexible-and much more useful-version " +"of our daytime program:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:983 +#, no-wrap +msgid "" +"/*\n" +" * daytime.c\n" +" *\n" +" * Programmed by G. Adam Stanislav\n" +" * 19 June 2001\n" +" */\n" +"#include <stdio.h>\n" +"#include <string.h>\n" +"#include <sys/types.h>\n" +"#include <sys/socket.h>\n" +"#include <netinet/in.h>\n" +"#include <netdb.h>\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:991 +#, no-wrap +msgid "" +"int main(int argc, char *argv[]) {\n" +" register int s;\n" +" register int bytes;\n" +" struct sockaddr_in sa;\n" +" struct hostent *he;\n" +" char buf[BUFSIZ+1];\n" +" char *host;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1001 +#, no-wrap +msgid "" +" sa.sin_family = AF_INET;\n" +" sa.sin_port = htons(13);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1003 +#, no-wrap +msgid " host = (argc > 1) ? (char *)argv[1] : \"time.nist.gov\";\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1008 +#, no-wrap +msgid "" +" if ((he = gethostbyname(host)) == NULL) {\n" +" herror(host);\n" +" return 2;\n" +" }\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1010 +#, no-wrap +msgid " bcopy(he->h_addr_list[0],&sa.sin_addr, he->h_length);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1015 +#, no-wrap +msgid "" +" if (connect(s, (struct sockaddr *)&sa, sizeof sa) < 0) {\n" +" perror(\"connect\");\n" +" return 3;\n" +" }\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1018 +#, no-wrap +msgid "" +" while ((bytes = read(s, buf, BUFSIZ)) > 0)\n" +" write(1, buf, bytes);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1028 +msgid "" +"We now can type a domain name (or an IP address, it works both ways) on the " +"command line, and the program will try to connect to its _daytime_ server. " +"Otherwise, it will still default to `time.nist.gov`. However, even in this " +"case we will use `gethostbyname` rather than hard coding `192.43.244.18`. " +"That way, even if its IP address changes in the future, we will still find " +"it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1032 +msgid "" +"Since it takes virtually no time to get the time from your local server, you " +"could run daytime twice in a row: First to get the time from `time.nist." +"gov`, the second time from your own system. You can then compare the " +"results and see how exact your system clock is:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1036 +#, no-wrap +msgid "% daytime ; daytime localhost\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1040 +#, no-wrap +msgid "" +"52080 01-06-20 04:02:33 50 0 0 390.2 UTC(NIST) *\n" +"2001-06-20T04:02:35Z\n" +"%\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1043 +msgid "As you can see, my system was two seconds ahead of the NIST time." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1045 +#, no-wrap +msgid "`getservbyname`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1049 +msgid "" +"Sometimes you may not be sure what port a certain service uses. The man:" +"getservbyname[3] function, also declared in [.filename]#netdb.h# comes in " +"very handy in those cases:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1053 +#, no-wrap +msgid "struct servent * getservbyname(const char *name, const char *proto);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1056 +msgid "" +"The `servent` structure contains the `s_port`, which contains the proper " +"port, already in _network byte order_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1058 +msgid "" +"Had we not known the correct port for the _daytime_ service, we could have " +"found it this way:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1068 +#, no-wrap +msgid "" +"struct servent *se;\n" +" ...\n" +" if ((se = getservbyname(\"daytime\", \"tcp\")) == NULL {\n" +" fprintf(stderr, \"Cannot determine which port to use.\\n\");\n" +" return 7;\n" +" }\n" +" sa.sin_port = se->s_port;\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1075 +msgid "" +"You usually do know the port. But if you are developing a new protocol, you " +"may be testing it on an unofficial port. Some day, you will register the " +"protocol and its port (if nowhere else, at least in your [.filename]#/etc/" +"services#, which is where `getservbyname` looks). Instead of returning an " +"error in the above code, you just use the temporary port number. Once you " +"have listed the protocol in [.filename]#/etc/services#, your software will " +"find its port without you having to rewrite the code." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1077 +#, no-wrap +msgid "Concurrent Servers" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1081 +msgid "" +"Unlike a sequential server, a _concurrent server_ has to be able to serve " +"more than one client at a time. For example, a _chat server_ may be serving " +"a specific client for hours-it cannot wait till it stops serving a client " +"before it serves the next one." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1083 +msgid "This requires a significant change in our flowchart:" +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1084 +#, no-wrap +msgid "Concurrent Server" +msgstr "" + +#. type: Target for macro image +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1085 +#, no-wrap +msgid "serv2.png" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1089 +msgid "" +"We moved the _serve_ from the _daemon process_ to its own _server process_. " +"However, because each child process inherits all open files (and a socket is " +"treated just like a file), the new process inherits not only the _\"accepted " +"handle,\"_ i.e., the socket returned by the `accept` call, but also the _top " +"socket_, i.e., the one opened by the top process right at the beginning." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1092 +msgid "" +"However, the _server process_ does not need this socket and should `close` " +"it immediately. Similarly, the _daemon process_ no longer needs the " +"_accepted socket_, and not only should, but _must_ `close` it-otherwise, it " +"will run out of available _file descriptors_ sooner or later." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1095 +msgid "" +"After the _server process_ is done serving, it should close the _accepted " +"socket_. Instead of returning to `accept`, it now exits." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1102 +msgid "" +"Under UNIX(R), a process does not really _exit_. Instead, it _returns_ to " +"its parent. Typically, a parent process ``wait``s for its child process, " +"and obtains a return value. However, our _daemon process_ cannot simply " +"stop and wait. That would defeat the whole purpose of creating additional " +"processes. But if it never does `wait`, its children will become _zombies_-" +"no longer functional but still roaming around." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1105 +msgid "" +"For that reason, the _daemon process_ needs to set _signal handlers_ in its " +"_initialize daemon_ phase. At least a SIGCHLD signal has to be processed, " +"so the daemon can remove the zombie return values from the system and " +"release the system resources they are taking up." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/sockets/_index.adoc:1108 +msgid "" +"That is why our flowchart now contains a _process signals_ box, which is not " +"connected to any other box. By the way, many servers also process SIGHUP, " +"and typically interpret as the signal from the superuser that they should " +"reread their configuration files. This allows us to change settings without " +"having to kill and restart these servers." +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/testing/_index.adoc b/documentation/content/en/books/developers-handbook/testing/_index.adoc index 72d039d239..4aae09a4ad 100644 --- a/documentation/content/en/books/developers-handbook/testing/_index.adoc +++ b/documentation/content/en/books/developers-handbook/testing/_index.adoc @@ -7,7 +7,7 @@ description: Regression and Performance Testing tags: ["Regression", "Performance Testing", "Testing", "Tinderbox"] showBookMenu: true weight: 7 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/testing/" --- [[testing]] diff --git a/documentation/content/en/books/developers-handbook/testing/_index.po b/documentation/content/en/books/developers-handbook/testing/_index.po new file mode 100644 index 0000000000..c1d21ea137 --- /dev/null +++ b/documentation/content/en/books/developers-handbook/testing/_index.po @@ -0,0 +1,614 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-02-01 09:21-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:1 +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:14 +#, no-wrap +msgid "Regression and Performance Testing" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:1 +#, no-wrap +msgid "Chapter 6. Regression and Performance Testing" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:52 +msgid "" +"Regression tests are used to exercise a particular bit of the system to " +"check that it works as expected, and to make sure that old bugs are not " +"reintroduced." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:54 +msgid "" +"The FreeBSD regression testing tools can be found in the FreeBSD source tree " +"in the directory [.filename]#src/tools/regression#." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:56 +#, no-wrap +msgid "Micro Benchmark Checklist" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:59 +msgid "" +"This section contains hints for doing proper micro-benchmarking on FreeBSD " +"or of FreeBSD itself." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:61 +msgid "" +"It is not possible to use all of the suggestions below every single time, " +"but the more used, the better the benchmark's ability to test small " +"differences will be." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:63 +msgid "Disable APM and any other kind of clock fiddling (ACPI ?)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:64 +msgid "" +"Run in single user mode. E.g., man:cron[8], and other daemons only add " +"noise. The man:sshd[8] daemon can also cause problems. If ssh access is " +"required during testing either disable the SSHv1 key regeneration, or kill " +"the parent `sshd` daemon during the tests." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:65 +msgid "Do not run man:ntpd[8]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:66 +msgid "" +"If man:syslog[3] events are generated, run man:syslogd[8] with an empty [." +"filename]#/etc/syslogd.conf#, otherwise, do not run it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:67 +msgid "Minimize disk-I/O, avoid it entirely if possible." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:68 +msgid "Do not mount file systems that are not needed." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:69 +msgid "" +"Mount [.filename]#/#, [.filename]#/usr#, and any other file system as read-" +"only if possible. This removes atime updates to disk (etc.) from the I/O " +"picture." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:70 +msgid "" +"Reinitialize the read/write test file system with man:newfs[8] and populate " +"it from a man:tar[1] or man:dump[8] file before every run. Unmount and mount " +"it before starting the test. This results in a consistent file system " +"layout. For a worldstone test this would apply to [.filename]#/usr/obj# " +"(just reinitialize with `newfs` and mount). To get 100% reproducibility, " +"populate the file system from a man:dd[1] file (i.e.: `dd if=myimage of=/dev/" +"ad0s1h bs=1m`)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:71 +msgid "Use malloc backed or preloaded man:md[4] partitions." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:72 +msgid "" +"Reboot between individual iterations of the test, this gives a more " +"consistent state." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:73 +msgid "" +"Remove all non-essential device drivers from the kernel. For instance if USB " +"is not needed for the test, do not put USB in the kernel. Drivers which " +"attach often have timeouts ticking away." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:74 +msgid "" +"Unconfigure hardware that are not in use. Detach disks with man:" +"atacontrol[8] and man:camcontrol[8] if the disks are not used for the test." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:75 +msgid "" +"Do not configure the network unless it is being tested, or wait until after " +"the test has been performed to ship the results off to another computer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:77 +msgid "" +"If the system must be connected to a public network, watch out for spikes of " +"broadcast traffic. Even though it is hardly noticeable, it will take up CPU " +"cycles. Multicast has similar caveats." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:78 +msgid "" +"Put each file system on its own disk. This minimizes jitter from head-seek " +"optimizations." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:79 +msgid "" +"Minimize output to serial or VGA consoles. Running output into files gives " +"less jitter. (Serial consoles easily become a bottleneck.) Do not touch " +"keyboard while the test is running, even kbd:[space] or kbd:[back-space] " +"shows up in the numbers." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:80 +msgid "" +"Make sure the test is long enough, but not too long. If the test is too " +"short, timestamping is a problem. If it is too long temperature changes and " +"drift will affect the frequency of the quartz crystals in the computer. Rule " +"of thumb: more than a minute, less than an hour." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:81 +msgid "" +"Try to keep the temperature as stable as possible around the machine. This " +"affects both quartz crystals and disk drive algorithms. To get real stable " +"clock, consider stabilized clock injection. E.g., get a OCXO + PLL, inject " +"output into clock circuits instead of motherboard xtal. Contact {phk} for " +"more information about this." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:82 +msgid "" +"Run the test at least 3 times but it is better to run more than 20 times " +"both for \"before\" and \"after\" code. Try to interleave if possible (i.e.: " +"do not run 20 times before then 20 times after), this makes it possible to " +"spot environmental effects. Do not interleave 1:1, but 3:3, this makes it " +"possible to spot interaction effects." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:85 +msgid "" +"A good pattern is: `bababa{bbbaaa}*`. This gives hint after the first 1+1 " +"runs (so it is possible to stop the test if it goes entirely the wrong way), " +"a standard deviation after the first 3+3 (gives a good indication if it is " +"going to be worth a long run) and trending and interaction numbers later on." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:86 +msgid "" +"Use man:ministat[1] to see if the numbers are significant. Consider buying " +"\"Cartoon guide to statistics\" ISBN: 0062731025, highly recommended, if you " +"have forgotten or never learned about standard deviation and Student's T." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:87 +msgid "" +"Do not use background man:fsck[8] unless the test is a benchmark of " +"background `fsck`. Also, disable `background_fsck` in [.filename]#/etc/rc." +"conf# unless the benchmark is not started at least 60+\"``fsck`` runtime\" " +"seconds after the boot, as man:rc[8] wakes up and checks if `fsck` needs to " +"run on any file systems when background `fsck` is enabled. Likewise, make " +"sure there are no snapshots lying around unless the benchmark is a test with " +"snapshots." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:88 +msgid "" +"If the benchmark show unexpected bad performance, check for things like high " +"interrupt volume from an unexpected source. Some versions of ACPI have been " +"reported to \"misbehave\" and generate excess interrupts. To help diagnose " +"odd test results, take a few snapshots of `vmstat -i` and look for anything " +"unusual." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:89 +msgid "" +"Make sure to be careful about optimization parameters for kernel and " +"userspace, likewise debugging. It is easy to let something slip through and " +"realize later the test was not comparing the same thing." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:90 +msgid "" +"Do not ever benchmark with the `WITNESS` and `INVARIANTS` kernel options " +"enabled unless the test is interested to benchmarking those features. " +"`WITNESS` can cause 400%+ drops in performance. Likewise, userspace man:" +"malloc[3] parameters default differently in -CURRENT from the way they ship " +"in production releases." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:92 +#, no-wrap +msgid "The FreeBSD Source Tinderbox" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:95 +msgid "The source Tinderbox consists of:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:97 +msgid "" +"A build script, [.filename]#tinderbox#, that automates checking out a " +"specific version of the FreeBSD source tree and building it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:98 +msgid "" +"A supervisor script, [.filename]#tbmaster#, that monitors individual " +"Tinderbox instances, logs their output, and emails failure notices." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:99 +msgid "" +"A CGI script named [.filename]#index.cgi# that reads a set of tbmaster logs " +"and presents an easy-to-read HTML summary of them." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:100 +msgid "" +"A set of build servers that continually test the tip of the most important " +"FreeBSD code branches." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:101 +msgid "" +"A webserver that keeps a complete set of Tinderbox logs and displays an up-" +"to-date summary." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:104 +msgid "" +"The scripts are maintained and were developed by {des}, and are now written " +"in Perl, a move on from their original incarnation as shell scripts. All " +"scripts and configuration files are kept in https://www.freebsd.org/cgi/" +"cvsweb.cgi/projects/tinderbox/[/projects/tinderbox/]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:106 +msgid "" +"For more information about the tinderbox and tbmaster scripts at this stage, " +"see their respective man pages: tinderbox(1) and tbmaster(1)." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:107 +#, no-wrap +msgid "The index.cgi Script" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:114 +msgid "" +"The [.filename]#index.cgi# script generates the HTML summary of tinderbox " +"and tbmaster logs. Although originally intended to be used as a CGI script, " +"as indicated by its name, this script can also be run from the command line " +"or from a man:cron[8] job, in which case it will look for logs in the " +"directory where the script is located. It will automatically detect " +"context, generating HTTP headers when it is run as a CGI script. It " +"conforms to XHTML standards and is styled using CSS." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:117 +msgid "" +"The script starts in the `main()` block by attempting to verify that it is " +"running on the official Tinderbox website. If it is not, a page indicating " +"it is not an official website is produced, and a URL to the official site is " +"provided." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:120 +msgid "" +"Next, it scans the log directory to get an inventory of configurations, " +"branches and architectures for which log files exist, to avoid hard-coding a " +"list into the script and potentially ending up with blank rows or columns. " +"This information is derived from the names of the log files matching the " +"following pattern:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:124 +#, no-wrap +msgid "tinderbox-$config-$branch-$arch-$machine.{brief,full}\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:128 +msgid "" +"The configurations used on the official Tinderbox build servers are named " +"for the branches they build. For example, the `releng_8` configuration is " +"used to build `RELENG_8` as well as all still-supported release branches." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:130 +msgid "" +"Once all of this startup procedure has been successfully completed, " +"`do_config()` is called for each configuration." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:132 +msgid "" +"The `do_config()` function generates HTML for a single Tinderbox " +"configuration." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:135 +msgid "" +"It works by first generating a header row, then iterating over each branch " +"build with the specified configuration, producing a single row of results " +"for each in the following manner:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:137 +msgid "For each item:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:139 +msgid "For each machine within that architecture:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:141 +msgid "If a brief log file exists, then:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:143 +msgid "Call `success()` to determine the outcome of the build." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:144 +msgid "Output the modification size." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:145 +msgid "" +"Output the size of the brief log file with a link to the log file itself." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:146 +msgid "If a full log file also exists, then:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:148 +msgid "" +"Output the size of the full log file with a link to the log file itself." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:150 +msgid "Otherwise:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:152 +msgid "No output." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:154 +msgid "" +"The `success()` function mentioned above scans a brief log file for the " +"string \"tinderbox run completed\" in order to determine whether the build " +"was successful." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:157 +msgid "" +"Configurations and branches are sorted according to their branch rank. This " +"is computed as follows:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:159 +msgid "`HEAD` and `CURRENT` have rank 9999." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:160 +msgid "`RELENG_x` has rank __``xx``__99." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:161 +msgid "`RELENG_x_y` has rank _xxyy_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:164 +msgid "" +"This means that `HEAD` always ranks highest, and `RELENG` branches are " +"ranked in numerical order, with each `STABLE` branch ranking higher than the " +"release branches forked off of it. For instance, for FreeBSD 8, the order " +"from highest to lowest would be:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:166 +msgid "`RELENG_8` (branch rank 899)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:167 +msgid "`RELENG_8_3` (branch rank 803)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:168 +msgid "`RELENG_8_2` (branch rank 802)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:169 +msgid "`RELENG_8_1` (branch rank 801)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:170 +msgid "`RELENG_8_0` (branch rank 800)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:174 +msgid "" +"The colors that Tinderbox uses for each cell in the table are defined by " +"CSS. Successful builds are displayed with green text; unsuccessful builds " +"are displayed with red text. The color fades as time passes since the " +"corresponding build, with every half an hour bringing the color closer to " +"grey." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:175 +#, no-wrap +msgid "Official Build Servers" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:178 +msgid "" +"The official Tinderbox build servers are hosted by http://www.sentex." +"ca[Sentex Data Communications], who also host the FreeBSD Netperf Cluster." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:180 +msgid "Three build servers currently exist:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:182 +msgid "_freebsd-current.sentex.ca_ builds:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:184 +msgid "" +"`HEAD` for amd64, arm, i386, i386/pc98, ia64, mips, powerpc, powerpc64, and " +"sparc64." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:185 +msgid "" +"`RELENG_9` and supported 9._X_ branches for amd64, arm, i386, i386/pc98, " +"ia64, mips, powerpc, powerpc64, and sparc64." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:187 +msgid "_freebsd-stable.sentex.ca_ builds:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:189 +msgid "" +"`RELENG_8` and supported 8._X_ branches for amd64, i386, i386/pc98, ia64, " +"mips, powerpc and sparc64." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:191 +msgid "_freebsd-legacy.sentex.ca_ builds:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:193 +msgid "" +"`RELENG_7` and supported 7._X_ branches for amd64, i386, i386/pc98, ia64, " +"powerpc, and sparc64." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:194 +#, no-wrap +msgid "Official Summary Site" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:197 +msgid "" +"Summaries and logs from the official build servers are available online at " +"http://tinderbox.FreeBSD.org[http://tinderbox.FreeBSD.org], hosted by {des} " +"and set up as follows:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:199 +msgid "" +"A man:cron[8] job checks the build servers at regular intervals and " +"downloads any new log files using man:rsync[1]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/testing/_index.adoc:199 +msgid "Apache is set up to use [.filename]#index.cgi# as `DirectoryIndex`." +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/tools/_index.adoc b/documentation/content/en/books/developers-handbook/tools/_index.adoc index c13521edc9..c1dbec7094 100644 --- a/documentation/content/en/books/developers-handbook/tools/_index.adoc +++ b/documentation/content/en/books/developers-handbook/tools/_index.adoc @@ -9,7 +9,7 @@ description: Programming Tools tags: ["tools", "Interpreters", "Compilers", "cc", "make", "Debugging", "lldb", "gdb", "clang", "Emacs"] showBookMenu: true weight: 3 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/tools/" --- [[tools]] @@ -158,14 +158,14 @@ Ruby:: Ruby is an interpreter, pure object-oriented programming language. It has become widely popular because of its easy to understand syntax, flexibility when writing code, and the ability to easily develop and maintain large, complex programs. + -Ruby is available from the Ports Collection as package:lang/ruby25[]. +Ruby is available from the Ports Collection as package:lang/ruby32[]. Tcl and Tk:: Tcl is an embeddable, interpreted language, that has become widely used and became popular mostly because of its portability to many platforms. It can be used both for quickly writing small, prototype applications, or (when combined with Tk, a GUI toolkit) fully-fledged, featureful programs. + Various versions of Tcl are available as ports for FreeBSD. -The latest version, Tcl 8.5, can be found in package:lang/tcl87[]. +The latest version, Tcl 8.7, can be found in package:lang/tcl87[]. === Compilers @@ -434,7 +434,7 @@ free(foo); Making one of these mistakes will not always lead to an error, but they are always bad practice. Some systems and compilers are more tolerant than others, -which is why programs that ran well on one system can crash when you try them on an another. +which is why programs that run well on one system can crash when you try them on another. ==== Sometimes when I get a core dump it says bus error. It says in my UNIX(R) book that this means a hardware problem, but the computer still seems to be working. Is this true? @@ -655,16 +655,7 @@ as they are very complicated (and if you do look at them, make sure you have a f `Make` is a very powerful tool, and can do much more than the simple example above shows. Unfortunately, there are several different versions of `make`, and they all differ considerably. The best way to learn what they can do is probably to read the documentation-hopefully this introduction will have given you a base from which you can do this. - -The version of make that comes with FreeBSD is the Berkeley make; there is a tutorial for it in [.filename]#/usr/share/doc/psd/12.make#. -To view it, do - -[source,bash] -.... -% zmore paper.ascii.gz -.... - -in that directory. +The man:make[1] manual page offers a comprehensive discussion of variables, arguments, and how to use make. Many applications in the ports use GNU make, which has a very good set of "info" pages. If you have installed any of these ports, GNU make will automatically have been installed as `gmake`. @@ -688,28 +679,25 @@ to the file. Once you have done this, you can type `info` and then select [.guim Using a debugger allows running the program under more controlled circumstances. Typically, it is possible to step through the program a line at a time, inspect the value of variables, change them, tell the debugger to run up to a certain point and then stop, and so on. It is also possible to attach to a program that is already running, or load a core file to investigate why the program crashed. -It is even possible to debug the kernel, though that is a little trickier than the user applications we will be discussing in this section. This section is intended to be a quick introduction to using debuggers and does not cover specialized topics such as debugging the kernel. For more information about that, refer to crossref:kerneldebug[kerneldebug,Kernel Debugging]. -The standard debugger supplied with FreeBSD {rel121-current} is called `lldb` (LLVM debugger). +The standard debugger supplied with FreeBSD is called `lldb` (LLVM debugger). As it is part of the standard installation for that release, there is no need to do anything special to use it. It has good command help, accessible via the `help` command, as well as https://lldb.llvm.org/[a web tutorial and documentation]. [NOTE] ==== -The `lldb` command is available for FreeBSD {rel113-current} extref:{handbook}[from ports or packages, ports-using] as package:devel/llvm[]. -This will install the default version of lldb (currently 9.0). +The `lldb` command is also available extref:{handbook}ports/[from ports or packages, ports-using] as package:devel/llvm[]. ==== The other debugger available with FreeBSD is called `gdb` (GNU debugger). -Unlike lldb, it is not installed by default on FreeBSD {rel121-current}; +Unlike lldb, it is not installed by default on FreeBSD; to use it, extref:{handbook}#ports-using/[install] package:devel/gdb[] from ports or packages. -The version installed by default on FreeBSD {rel113-current} is old; instead, install package:devel/gdb[] there as well. -It has quite good on-line help, as well as a set of info pages. +It has excellent on-line help, as well as a set of info pages. -Which one to use is largely a matter of taste. +The two debuggers have a similar feature set, so which one to use is largely a matter of taste. If familiar with one only, use that one. People familiar with neither or both but wanting to use one from inside Emacs will need to use `gdb` as `lldb` is unsupported by Emacs. Otherwise, try both and see which one you prefer. @@ -884,7 +872,7 @@ In "the good old days", programmers had to print out hex listings of core files Incidentally, under FreeBSD and other 4.4BSD systems, a core file is called [.filename]#progname.core# instead of just [.filename]#core#, to make it clearer which program a core file belongs to. To examine a core file, specify the name of the core file in addition to the program itself. -Instead of starting up `lldb` in the usual way, type `lldb -c _progname_.core -- _progname_` +Instead of starting up `lldb` in the usual way, type `lldb -c _progname_.core \-- _progname_`. The debugger will display something like this: @@ -1260,7 +1248,7 @@ Instead of using a proprietary macro language for configuration, Emacs uses a ve Working with Emacs Lisp can be quite helpful if you want to go on and learn something like Common Lisp. Emacs Lisp has many features of Common Lisp, although it is considerably smaller (and thus easier to master). -The best way to learn Emacs Lisp is to download the link:ftp://ftp.gnu.org/old-gnu/emacs/elisp-manual-19-2.4.tar.gz[Emacs Tutorial] +The best way to learn Emacs Lisp is to read the online link:https://www.gnu.org/software/emacs/manual/elisp.html[Emacs Reference] manual. However, there is no need to actually know any Lisp to get started with configuring Emacs, as I have included a sample [.filename]#.emacs#, which should be enough to get you started. diff --git a/documentation/content/en/books/developers-handbook/tools/_index.po b/documentation/content/en/books/developers-handbook/tools/_index.po new file mode 100644 index 0000000000..c1ccabc167 --- /dev/null +++ b/documentation/content/en/books/developers-handbook/tools/_index.po @@ -0,0 +1,3356 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2024-01-17 20:34-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:16 +#, no-wrap +msgid "Programming Tools" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1 +#, no-wrap +msgid "Chapter 2. Programming Tools" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:56 +#, no-wrap +msgid "Synopsis" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:63 +msgid "" +"This chapter is an introduction to using some of the programming tools " +"supplied with FreeBSD, although much of it will be applicable to many other " +"versions of UNIX(R). It does _not_ attempt to describe coding in any " +"detail. Most of the chapter assumes little or no previous programming " +"knowledge, although it is hoped that most programmers will find something of " +"value in it." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:65 +#, no-wrap +msgid "Introduction" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:72 +msgid "" +"FreeBSD offers an excellent development environment. Compilers for C and C+" +"+ and an assembler come with the basic system, not to mention classic " +"UNIX(R) tools such as `sed` and `awk`. If that is not enough, there are " +"many more compilers and interpreters in the Ports collection. The following " +"section, <<tools-programming,Introduction to Programming>>, lists some of " +"the available options. FreeBSD is very compatible with standards such as " +"POSIX(R) and ANSI C, as well with its own BSD heritage, so it is possible to " +"write applications that will compile and run with little or no modification " +"on a wide range of platforms." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:76 +msgid "" +"However, all this power can be rather overwhelming at first if you have " +"never written programs on a UNIX(R) platform before. This document aims to " +"help you get up and running, without getting too deeply into more advanced " +"topics. The intention is that this document should give you enough of the " +"basics to be able to make some sense of the documentation." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:78 +msgid "" +"Most of the document requires little or no knowledge of programming, " +"although it does assume a basic competence with using UNIX(R) and a " +"willingness to learn!" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:80 +#, no-wrap +msgid "Introduction to Programming" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:86 +msgid "" +"A program is a set of instructions that tell the computer to do various " +"things; sometimes the instruction it has to perform depends on what happened " +"when it performed a previous instruction. This section gives an overview of " +"the two main ways in which you can give these instructions, or \"commands\" " +"as they are usually called. One way uses an _interpreter_, the other a " +"_compiler_. As human languages are too difficult for a computer to " +"understand in an unambiguous way, commands are usually written in one or " +"other languages specially designed for the purpose." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:87 +#, no-wrap +msgid "Interpreters" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:92 +msgid "" +"With an interpreter, the language comes as an environment, where you type in " +"commands at a prompt and the environment executes them for you. For more " +"complicated programs, you can type the commands into a file and get the " +"interpreter to load the file and execute the commands in it. If anything " +"goes wrong, many interpreters will drop you into a debugger to help you " +"track down the problem." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:97 +msgid "" +"The advantage of this is that you can see the results of your commands " +"immediately, and mistakes can be corrected readily. The biggest " +"disadvantage comes when you want to share your programs with someone. They " +"must have the same interpreter, or you must have some way of giving it to " +"them, and they need to understand how to use it. Also users may not " +"appreciate being thrown into a debugger if they press the wrong key! From a " +"performance point of view, interpreters can use up a lot of memory, and " +"generally do not generate code as efficiently as compilers." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:102 +msgid "" +"In my opinion, interpreted languages are the best way to start if you have " +"not done any programming before. This kind of environment is typically " +"found with languages like Lisp, Smalltalk, Perl and Basic. It could also be " +"argued that the UNIX(R) shell (`sh`, `csh`) is itself an interpreter, and " +"many people do in fact write shell \"scripts\" to help with various " +"\"housekeeping\" tasks on their machine. Indeed, part of the original " +"UNIX(R) philosophy was to provide lots of small utility programs that could " +"be linked together in shell scripts to perform useful tasks." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:103 +#, no-wrap +msgid "Interpreters Available with FreeBSD" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:106 +msgid "" +"Here is a list of interpreters that are available from the FreeBSD Ports " +"Collection, with a brief discussion of some of the more popular interpreted " +"languages." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:108 +msgid "" +"Instructions on how to get and install applications from the Ports " +"Collection can be found in the extref:{handbook}[Ports section, ports-using] " +"of the handbook." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:109 +#, no-wrap +msgid "BASIC" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:113 +msgid "" +"Short for Beginner's All-purpose Symbolic Instruction Code. Developed in " +"the 1950s for teaching University students to program and provided with " +"every self-respecting personal computer in the 1980s, BASIC has been the " +"first programming language for many programmers. It is also the foundation " +"for Visual Basic." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:115 +msgid "" +"The Bywater Basic Interpreter can be found in the Ports Collection as " +"package:lang/bwbasic[] and the Phil Cockroft's Basic Interpreter (formerly " +"Rabbit Basic) is available as package:lang/pbasic[]." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:116 +#, no-wrap +msgid "Lisp" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:120 +msgid "" +"A language that was developed in the late 1950s as an alternative to the " +"\"number-crunching\" languages that were popular at the time. Instead of " +"being based on numbers, Lisp is based on lists; in fact, the name is short " +"for \"List Processing\". It is very popular in AI (Artificial Intelligence) " +"circles." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:122 +msgid "" +"Lisp is an extremely powerful and sophisticated language, but can be rather " +"large and unwieldy." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:127 +msgid "" +"Various implementations of Lisp that can run on UNIX(R) systems are " +"available in the Ports Collection for FreeBSD. GNU Common Lisp can be found " +"as package:lang/gcl[]. CLISP by Bruno Haible and Michael Stoll is available " +"as package:lang/clisp[]. For CMUCL, which includes a highly-optimizing " +"compiler too, or simpler Lisp implementations like SLisp, which implements " +"most of the Common Lisp constructs in a few hundred lines of C code, package:" +"lang/cmucl[] and package:lang/slisp[] are available respectively." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:128 +#, no-wrap +msgid "Perl" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:130 +msgid "" +"Very popular with system administrators for writing scripts; also often used " +"on World Wide Web servers for writing CGI scripts." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:132 +msgid "" +"Perl is available in the Ports Collection as package:lang/perl5.24[] for all " +"FreeBSD releases." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:133 +#, no-wrap +msgid "Scheme" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:137 +msgid "" +"A dialect of Lisp that is rather more compact and cleaner than Common Lisp. " +"Popular in Universities as it is simple enough to teach to undergraduates as " +"a first language, while it has a high enough level of abstraction to be used " +"in research work." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:140 +msgid "" +"Scheme is available from the Ports Collection as package:lang/elk[] for the " +"Elk Scheme Interpreter. The MIT Scheme Interpreter can be found in package:" +"lang/mit-scheme[] and the SCM Scheme Interpreter in package:lang/scm[]." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:141 +#, no-wrap +msgid "Icon" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:144 +msgid "" +"Icon is a high-level language with extensive facilities for processing " +"strings and structures. The version of Icon for FreeBSD can be found in the " +"Ports Collection as package:lang/icon[]." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:145 +#, no-wrap +msgid "Logo" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:148 +msgid "" +"Logo is a language that is easy to learn, and has been used as an " +"introductory programming language in various courses. It is an excellent " +"tool to work with when teaching programming to smaller age groups, as it " +"makes creation of elaborate geometric shapes an easy task." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:150 +msgid "" +"The latest version of Logo for FreeBSD is available from the Ports " +"Collection in package:lang/logo[]." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:151 +#, no-wrap +msgid "Python" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:154 +msgid "" +"Python is an Object-Oriented, interpreted language. Its advocates argue " +"that it is one of the best languages to start programming with, since it is " +"relatively easy to start with, but is not limited in comparison to other " +"popular interpreted languages that are used for the development of large, " +"complex applications (Perl and Tcl are two other languages that are popular " +"for such tasks)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:156 +msgid "" +"The latest version of Python is available from the Ports Collection in " +"package:lang/python[]." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:157 +#, no-wrap +msgid "Ruby" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:160 +msgid "" +"Ruby is an interpreter, pure object-oriented programming language. It has " +"become widely popular because of its easy to understand syntax, flexibility " +"when writing code, and the ability to easily develop and maintain large, " +"complex programs." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:162 +msgid "Ruby is available from the Ports Collection as package:lang/ruby32[]." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:163 +#, no-wrap +msgid "Tcl and Tk" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:166 +msgid "" +"Tcl is an embeddable, interpreted language, that has become widely used and " +"became popular mostly because of its portability to many platforms. It can " +"be used both for quickly writing small, prototype applications, or (when " +"combined with Tk, a GUI toolkit) fully-fledged, featureful programs." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:169 +msgid "" +"Various versions of Tcl are available as ports for FreeBSD. The latest " +"version, Tcl 8.5, can be found in package:lang/tcl87[]." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:170 +#, no-wrap +msgid "Compilers" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:177 +msgid "" +"Compilers are rather different. First of all, you write your code in a file " +"(or files) using an editor. You then run the compiler and see if it accepts " +"your program. If it did not compile, grit your teeth and go back to the " +"editor; if it did compile and gave you a program, you can run it either at a " +"shell command prompt or in a debugger to see if it works properly.footnote:" +"[If you run it in the shell, you may get a core dump.]" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:184 +msgid "" +"Obviously, this is not quite as direct as using an interpreter. However it " +"allows you to do a lot of things which are very difficult or even impossible " +"with an interpreter, such as writing code which interacts closely with the " +"operating system-or even writing your own operating system! It is also " +"useful if you need to write very efficient code, as the compiler can take " +"its time and optimize the code, which would not be acceptable in an " +"interpreter. Moreover, distributing a program written for a compiler is " +"usually more straightforward than one written for an interpreter-you can " +"just give them a copy of the executable, assuming they have the same " +"operating system as you." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:188 +msgid "" +"As the edit-compile-run-debug cycle is rather tedious when using separate " +"programs, many commercial compiler makers have produced Integrated " +"Development Environments (IDEs for short). FreeBSD does not include an IDE " +"in the base system, but package:devel/kdevelop[] is available in the Ports " +"Collection and many use Emacs for this purpose. Using Emacs as an IDE is " +"discussed in <<emacs>>." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:190 +#, no-wrap +msgid "Compiling with `cc`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:195 +msgid "" +"This section deals with the clang compiler for C and C++, as it's installed " +"with the FreeBSD base system. Starting with FreeBSD 10.X `clang` is " +"installed as `cc`; the GNU compiler package:lang/gcc[gcc] is available in " +"the Ports Collection. The details of producing a program with an " +"interpreter vary considerably between interpreters, and are usually well " +"covered in the documentation and on-line help for the interpreter." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:198 +msgid "" +"Once you have written your masterpiece, the next step is to convert it into " +"something that will (hopefully!) run on FreeBSD. This usually involves " +"several steps, each of which is done by a separate program." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:201 +msgid "" +"Pre-process your source code to remove comments and do other tricks like " +"expanding macros in C." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:202 +msgid "" +"Check the syntax of your code to see if you have obeyed the rules of the " +"language. If you have not, it will complain!" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:203 +msgid "" +"Convert the source code into assembly language-this is very close to machine " +"code, but still understandable by humans. Allegedly." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:204 +msgid "" +"Convert the assembly language into machine code-yep, we are talking bits and " +"bytes, ones and zeros here." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:205 +msgid "" +"Check that you have used things like functions and global variables in a " +"consistent way. For example, if you have called a non-existent function, it " +"will complain." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:206 +msgid "" +"If you are trying to produce an executable from several source code files, " +"work out how to fit them all together." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:207 +msgid "" +"Work out how to produce something that the system's run-time loader will be " +"able to load into memory and run." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:208 +msgid "Finally, write the executable on the filesystem." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:211 +msgid "" +"The word _compiling_ is often used to refer to just steps 1 to 4-the others " +"are referred to as _linking_. Sometimes step 1 is referred to as _pre-" +"processing_ and steps 3-4 as _assembling_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:213 +msgid "" +"Fortunately, almost all this detail is hidden from you, as `cc` is a front " +"end that manages calling all these programs with the right arguments for " +"you; simply typing" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:217 +#, no-wrap +msgid "% cc foobar.c\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:221 +msgid "" +"will cause [.filename]#foobar.c# to be compiled by all the steps above. If " +"you have more than one file to compile, just do something like" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:225 +#, no-wrap +msgid "% cc foo.c bar.c\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:230 +msgid "" +"Note that the syntax checking is just that - checking the syntax. It will " +"not check for any logical mistakes you may have made, like putting the " +"program into an infinite loop, or using a bubble sort when you meant to use " +"a binary sort.footnote:[In case you did not know, a binary sort is an " +"efficient way of sorting things into order and a bubble sort is not.]" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:233 +msgid "" +"There are lots and lots of options for `cc`, which are all in the manual " +"page. Here are a few of the most important ones, with examples of how to " +"use them." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:234 +#, no-wrap +msgid "`-o _filename_`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:236 +msgid "" +"The output name of the file. If you do not use this option, `cc` will " +"produce an executable called [.filename]#a.out#.footnote:[The reasons for " +"this are buried in the mists of history.]" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:241 +#, no-wrap +msgid "" +"% cc foobar.c executable is a.out\n" +"% cc -o foobar foobar.c executable is foobar\n" +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:243 +#, no-wrap +msgid "`-c`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:246 +msgid "" +"Just compile the file, do not link it. Useful for toy programs where you " +"just want to check the syntax, or if you are using a [.filename]#Makefile#." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:250 +#, no-wrap +msgid "% cc -c foobar.c\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:254 +msgid "" +"This will produce an _object file_ (not an executable) called [." +"filename]#foobar.o#. This can be linked together with other object files " +"into an executable." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:255 +#, no-wrap +msgid "`-g`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:261 +msgid "" +"Create a debug version of the executable. This makes the compiler put " +"information into the executable about which line of which source file " +"corresponds to which function call. A debugger can use this information to " +"show the source code as you step through the program, which is _very_ " +"useful; the disadvantage is that all this extra information makes the " +"program much bigger. Normally, you compile with `-g` while you are " +"developing a program and then compile a \"release version\" without `-g` " +"when you are satisfied it works properly." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:266 +#, no-wrap +msgid "% cc -g foobar.c\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:269 +msgid "" +"This will produce a debug version of the program. footnote:[Note, we did not " +"use the -o flag to specify the executable name, so we will get an executable " +"called a.out. Producing a debug version called foobar is left as an exercise " +"for the reader!]" +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:270 +#, no-wrap +msgid "`-O`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:274 +msgid "" +"Create an optimized version of the executable. The compiler performs " +"various clever tricks to try to produce an executable that runs faster than " +"normal. You can add a number after the `-O` to specify a higher level of " +"optimization, but this often exposes bugs in the compiler's optimizer." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:278 +#, no-wrap +msgid "% cc -O -o foobar foobar.c\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:281 +msgid "This will produce an optimized version of [.filename]#foobar#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:284 +msgid "" +"The following three flags will force `cc` to check that your code complies " +"to the relevant international standard, often referred to as the ANSI " +"standard, though strictly speaking it is an ISO standard." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:285 +#, no-wrap +msgid "`-Wall`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:288 +msgid "" +"Enable all the warnings which the authors of `cc` believe are worthwhile. " +"Despite the name, it will not enable all the warnings `cc` is capable of." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:289 +#, no-wrap +msgid "`-ansi`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:292 +msgid "" +"Turn off most, but not all, of the non-ANSI C features provided by `cc`. " +"Despite the name, it does not guarantee strictly that your code will comply " +"to the standard." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:293 +#, no-wrap +msgid "`-pedantic`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:295 +msgid "Turn off _all_ ``cc``'s non-ANSI C features." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:300 +msgid "" +"Without these flags, `cc` will allow you to use some of its non-standard " +"extensions to the standard. Some of these are very useful, but will not " +"work with other compilers - in fact, one of the main aims of the standard is " +"to allow people to write code that will work with any compiler on any " +"system. This is known as _portable code_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:303 +msgid "" +"Generally, you should try to make your code as portable as possible, as " +"otherwise you may have to completely rewrite the program later to get it to " +"work somewhere else - and who knows what you may be using in a few years " +"time?" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:307 +#, no-wrap +msgid "% cc -Wall -ansi -pedantic -o foobar foobar.c\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:310 +msgid "" +"This will produce an executable [.filename]#foobar# after checking [." +"filename]#foobar.c# for standard compliance." +msgstr "" + +#. type: Labeled list +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:311 +#, no-wrap +msgid "`-l__library__`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:313 +msgid "Specify a function library to be used at link time." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:316 +msgid "" +"The most common example of this is when compiling a program that uses some " +"of the mathematical functions in C. Unlike most other platforms, these are " +"in a separate library from the standard C one and you have to tell the " +"compiler to add it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:320 +msgid "" +"The rule is that if the library is called [.filename]#libsomething.a#, you " +"give `cc` the argument `-l__something__`. For example, the math library is " +"[.filename]#libm.a#, so you give `cc` the argument `-lm`. A common " +"\"gotcha\" with the math library is that it has to be the last library on " +"the command line." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:324 +#, no-wrap +msgid "% cc -o foobar foobar.c -lm\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:327 +msgid "This will link the math library functions into [.filename]#foobar#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:330 +msgid "" +"If you are compiling C++ code, use {c-plus-plus-command}. {c-plus-plus-" +"command} can also be invoked as {clang-plus-plus-command} on FreeBSD." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:334 +#, no-wrap +msgid "% c++ -o foobar foobar.cc\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:337 +msgid "" +"This will both produce an executable [.filename]#foobar# from the C++ source " +"file [.filename]#foobar.cc#." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:338 +#, no-wrap +msgid "Common `cc` Queries and Problems" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:340 +#, no-wrap +msgid "I compiled a file called foobar.c and I cannot find an executable called foobar. Where has it gone?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:344 +msgid "" +"Remember, `cc` will call the executable [.filename]#a.out# unless you tell " +"it differently. Use the `-o _filename_` option:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:348 +#, no-wrap +msgid "% cc -o foobar foobar.c\n" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:350 +#, no-wrap +msgid "OK, I have an executable called foobar, I can see it when I run ls, but when I type in foobar at the command prompt it tells me there is no such file. Why can it not find it?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:354 +msgid "" +"Unlike MS-DOS(R), UNIX(R) does not look in the current directory when it is " +"trying to find out which executable you want it to run, unless you tell it " +"to. Type `./foobar`, which means \"run the file called [.filename]#foobar# " +"in the current directory.\"" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:355 +#, no-wrap +msgid "I called my executable test, but nothing happens when I run it. What is going on?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:359 +msgid "" +"Most UNIX(R) systems have a program called `test` in [.filename]#/usr/bin# " +"and the shell is picking that one up before it gets to checking the current " +"directory. Either type:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:363 +#, no-wrap +msgid "% ./test\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:366 +msgid "or choose a better name for your program!" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:367 +#, no-wrap +msgid "I compiled my program and it seemed to run all right at first, then there was an error and it said something about core dumped. What does that mean?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:371 +msgid "" +"The name _core dump_ dates back to the very early days of UNIX(R), when the " +"machines used core memory for storing data. Basically, if the program " +"failed under certain conditions, the system would write the contents of core " +"memory to disk in a file called [.filename]#core#, which the programmer " +"could then pore over to find out what went wrong." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:372 +#, no-wrap +msgid "Fascinating stuff, but what I am supposed to do now?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:375 +msgid "Use a debugger to analyze the core (see <<debugging>>)." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:376 +#, no-wrap +msgid "When my program dumped core, it said something about a segmentation fault. What is that?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:380 +msgid "" +"This basically means that your program tried to perform some sort of illegal " +"operation on memory; UNIX(R) is designed to protect the operating system and " +"other programs from rogue programs." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:382 +msgid "Common causes for this are:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:384 +msgid "Trying to write to a NULL pointer, eg" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:389 +#, no-wrap +msgid "" +"char *foo = NULL;\n" +"strcpy(foo, \"bang!\");\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:392 +msgid "Using a pointer that has not been initialized, eg" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:397 +#, no-wrap +msgid "" +"char *foo;\n" +"strcpy(foo, \"bang!\");\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:401 +msgid "" +"The pointer will have some random value that, with luck, will point into an " +"area of memory that is not available to your program and the kernel will " +"kill your program before it can do any damage. If you are unlucky, it will " +"point somewhere inside your own program and corrupt one of your data " +"structures, causing the program to fail mysteriously." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:402 +msgid "Trying to access past the end of an array, eg" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:407 +#, no-wrap +msgid "" +"int bar[20];\n" +"bar[27] = 6;\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:410 +msgid "Trying to store something in read-only memory, eg" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:415 +#, no-wrap +msgid "" +"char *foo = \"My string\";\n" +"strcpy(foo, \"bang!\");\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:418 +msgid "" +"UNIX(R) compilers often put string literals like `\"My string\"` into read-" +"only areas of memory." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:419 +msgid "Doing naughty things with `malloc()` and `free()`, eg" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:424 +#, no-wrap +msgid "" +"char bar[80];\n" +"free(bar);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:427 +msgid "or" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:433 +#, no-wrap +msgid "" +"char *foo = malloc(27);\n" +"free(foo);\n" +"free(foo);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:438 +msgid "" +"Making one of these mistakes will not always lead to an error, but they are " +"always bad practice. Some systems and compilers are more tolerant than " +"others, which is why programs that ran well on one system can crash when you " +"try them on an another." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:439 +#, no-wrap +msgid "Sometimes when I get a core dump it says bus error. It says in my UNIX(R) book that this means a hardware problem, but the computer still seems to be working. Is this true?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:443 +msgid "" +"No, fortunately not (unless of course you really do have a hardware " +"problem...). This is usually another way of saying that you accessed memory " +"in a way you should not have." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:444 +#, no-wrap +msgid "This dumping core business sounds as though it could be quite useful, if I can make it happen when I want to. Can I do this, or do I have to wait until there is an error?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:447 +msgid "Yes, just go to another console or xterm, do" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:451 +#, no-wrap +msgid "% ps\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:454 +msgid "to find out the process ID of your program, and do" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:458 +#, no-wrap +msgid "% kill -ABRT pid\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:461 +msgid "where `_pid_` is the process ID you looked up." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:464 +msgid "" +"This is useful if your program has got stuck in an infinite loop, for " +"instance. If your program happens to trap SIGABRT, there are several other " +"signals which have a similar effect." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:467 +msgid "" +"Alternatively, you can create a core dump from inside your program, by " +"calling the `abort()` function. See the manual page of man:abort[3] to " +"learn more." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:470 +msgid "" +"If you want to create a core dump from outside your program, but do not want " +"the process to terminate, you can use the `gcore` program. See the manual " +"page of man:gcore[1] for more information." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:472 +#, no-wrap +msgid "Make" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:474 +#, no-wrap +msgid "What is `make`?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:477 +msgid "" +"When you are working on a simple program with only one or two source files, " +"typing in" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:481 +#, no-wrap +msgid "% cc file1.c file2.c\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:484 +msgid "" +"is not too bad, but it quickly becomes very tedious when there are several " +"files-and it can take a while to compile, too." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:487 +msgid "" +"One way to get around this is to use object files and only recompile the " +"source file if the source code has changed. So we could have something like:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:491 +#, no-wrap +msgid "% cc file1.o file2.o … file37.c …\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:495 +msgid "" +"if we had changed [.filename]#file37.c#, but not any of the others, since " +"the last time we compiled. This may speed up the compilation quite a bit, " +"but does not solve the typing problem." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:497 +msgid "" +"Or we could write a shell script to solve the typing problem, but it would " +"have to re-compile everything, making it very inefficient on a large project." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:499 +msgid "" +"What happens if we have hundreds of source files lying about? What if we are " +"working in a team with other people who forget to tell us when they have " +"changed one of their source files that we use?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:502 +msgid "" +"Perhaps we could put the two solutions together and write something like a " +"shell script that would contain some kind of magic rule saying when a source " +"file needs compiling. Now all we need now is a program that can understand " +"these rules, as it is a bit too complicated for the shell." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:507 +msgid "" +"This program is called `make`. It reads in a file, called a _makefile_, " +"that tells it how different files depend on each other, and works out which " +"files need to be re-compiled and which ones do not. For example, a rule " +"could say something like \"if [.filename]#fromboz.o# is older than [." +"filename]#fromboz.c#, that means someone must have changed [." +"filename]#fromboz.c#, so it needs to be re-compiled.\" The makefile also has " +"rules telling make _how_ to re-compile the source file, making it a much " +"more powerful tool." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:510 +msgid "" +"Makefiles are typically kept in the same directory as the source they apply " +"to, and can be called [.filename]#makefile#, [.filename]#Makefile# or [." +"filename]#MAKEFILE#. Most programmers use the name [.filename]#Makefile#, " +"as this puts it near the top of a directory listing, where it can easily be " +"seen.footnote:[They do not use the MAKEFILE form as block capitals are often " +"used for documentation files like README.]" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:511 +#, no-wrap +msgid "Example of Using `make`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:514 +msgid "Here is a very simple make file:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:519 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:545 +#, no-wrap +msgid "" +"foo: foo.c\n" +"\tcc -o foo foo.c\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:522 +msgid "It consists of two lines, a dependency line and a creation line." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:529 +msgid "" +"The dependency line here consists of the name of the program (known as the " +"_target_), followed by a colon, then whitespace, then the name of the source " +"file. When `make` reads this line, it looks to see if [.filename]#foo# " +"exists; if it exists, it compares the time [.filename]#foo# was last " +"modified to the time [.filename]#foo.c# was last modified. If [." +"filename]#foo# does not exist, or is older than [.filename]#foo.c#, it then " +"looks at the creation line to find out what to do. In other words, this is " +"the rule for working out when [.filename]#foo.c# needs to be re-compiled." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:533 +msgid "" +"The creation line starts with a tab (press kbd:[tab]) and then the command " +"you would type to create [.filename]#foo# if you were doing it at a command " +"prompt. If [.filename]#foo# is out of date, or does not exist, `make` then " +"executes this command to create it. In other words, this is the rule which " +"tells make how to re-compile [.filename]#foo.c#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:537 +msgid "" +"So, when you type `make`, it will make sure that [.filename]#foo# is up to " +"date with respect to your latest changes to [.filename]#foo.c#. This " +"principle can be extended to [.filename]#Makefile#'s with hundreds of " +"targets-in fact, on FreeBSD, it is possible to compile the entire operating " +"system just by typing `make world` in the appropriate directory!" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:540 +msgid "" +"Another useful property of makefiles is that the targets do not have to be " +"programs. For instance, we could have a make file that looks like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:548 +#, no-wrap +msgid "" +"install:\n" +"\tcp foo /home/me\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:551 +msgid "We can tell make which target we want to make by typing:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:555 +#, no-wrap +msgid "% make target\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:559 +msgid "" +"`make` will then only look at that target and ignore any others. For " +"example, if we type `make foo` with the makefile above, make will ignore the " +"`install` target." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:562 +msgid "" +"If we just type `make` on its own, make will always look at the first target " +"and then stop without looking at any others. So if we typed `make` here, it " +"will just go to the `foo` target, re-compile [.filename]#foo# if necessary, " +"and then stop without going on to the `install` target." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:566 +msgid "" +"Notice that the `install` target does not actually depend on anything! This " +"means that the command on the following line is always executed when we try " +"to make that target by typing `make install`. In this case, it will copy [." +"filename]#foo# into the user's home directory. This is often used by " +"application makefiles, so that the application can be installed in the " +"correct directory when it has been correctly compiled." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:571 +msgid "" +"This is a slightly confusing subject to try to explain. If you do not quite " +"understand how `make` works, the best thing to do is to write a simple " +"program like \"hello world\" and a make file like the one above and " +"experiment. Then progress to using more than one source file, or having the " +"source file include a header file. `touch` is very useful here-it changes " +"the date on a file without you having to edit it." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:572 +#, no-wrap +msgid "Make and include-files" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:576 +msgid "" +"C code often starts with a list of files to include, for example stdio.h. " +"Some of these files are system-include files, some of them are from the " +"project you are now working on:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:581 +#, no-wrap +msgid "" +"#include <stdio.h>\n" +"#include \"foo.h\"\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:583 +#, no-wrap +msgid "int main(....\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:586 +msgid "" +"To make sure that this file is recompiled the moment [.filename]#foo.h# is " +"changed, you have to add it in your [.filename]#Makefile#:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:590 +#, no-wrap +msgid "foo: foo.c foo.h\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:597 +msgid "" +"The moment your project is getting bigger and you have more and more own " +"include-files to maintain, it will be a pain to keep track of all include " +"files and the files which are depending on it. If you change an include-" +"file but forget to recompile all the files which are depending on it, the " +"results will be devastating. `clang` has an option to analyze your files " +"and to produce a list of include-files and their dependencies: `-MM`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:599 +msgid "If you add this to your Makefile:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:604 +#, no-wrap +msgid "" +"depend:\n" +"\tcc -E -MM *.c > .depend\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:607 +msgid "" +"and run `make depend`, the file [.filename]#.depend# will appear with a list " +"of object-files, C-files and the include-files:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:611 +#, no-wrap +msgid "foo.o: foo.c foo.h\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:614 +msgid "" +"If you change [.filename]#foo.h#, next time you run `make` all files " +"depending on [.filename]#foo.h# will be recompiled." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:616 +msgid "" +"Do not forget to run `make depend` each time you add an include-file to one " +"of your files." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:617 +#, no-wrap +msgid "FreeBSD Makefiles" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:623 +msgid "" +"Makefiles can be rather complicated to write. Fortunately, BSD-based " +"systems like FreeBSD come with some very powerful ones as part of the " +"system. One very good example of this is the FreeBSD ports system. Here is " +"the essential part of a typical ports [.filename]#Makefile#:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:628 +#, no-wrap +msgid "" +"MASTER_SITES= ftp://freefall.cdrom.com/pub/FreeBSD/LOCAL_PORTS/\n" +"DISTFILES= scheme-microcode+dist-7.3-freebsd.tgz\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:630 +#, no-wrap +msgid ".include <bsd.port.mk>\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:633 +msgid "" +"Now, if we go to the directory for this port and type `make`, the following " +"happens:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:636 +msgid "" +"A check is made to see if the source code for this port is already on the " +"system." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:637 +msgid "" +"If it is not, an FTP connection to the URL in MASTER_SITES is set up to " +"download the source." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:638 +msgid "" +"The checksum for the source is calculated and compared it with one for a " +"known, good, copy of the source. This is to make sure that the source was " +"not corrupted while in transit." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:639 +msgid "" +"Any changes required to make the source work on FreeBSD are applied-this is " +"known as _patching_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:640 +msgid "" +"Any special configuration needed for the source is done. (Many UNIX(R) " +"program distributions try to work out which version of UNIX(R) they are " +"being compiled on and which optional UNIX(R) features are present-this is " +"where they are given the information in the FreeBSD ports scenario)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:641 +msgid "" +"The source code for the program is compiled. In effect, we change to the " +"directory where the source was unpacked and do `make`-the program's own make " +"file has the necessary information to build the program." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:642 +msgid "" +"We now have a compiled version of the program. If we wish, we can test it " +"now; when we feel confident about the program, we can type `make install`. " +"This will cause the program and any supporting files it needs to be copied " +"into the correct location; an entry is also made into a `package database`, " +"so that the port can easily be uninstalled later if we change our mind about " +"it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:644 +msgid "" +"Now I think you will agree that is rather impressive for a four line script!" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:648 +msgid "" +"The secret lies in the last line, which tells `make` to look in the system " +"makefile called [.filename]#bsd.port.mk#. It is easy to overlook this line, " +"but this is where all the clever stuff comes from-someone has written a " +"makefile that tells `make` to do all the things above (plus a couple of " +"other things I did not mention, including handling any errors that may " +"occur) and anyone can get access to that just by putting a single line in " +"their own make file!" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:652 +msgid "" +"If you want to have a look at these system makefiles, they are in [." +"filename]#/usr/share/mk#, but it is probably best to wait until you have had " +"a bit of practice with makefiles, as they are very complicated (and if you " +"do look at them, make sure you have a flask of strong coffee handy!)" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:653 +#, no-wrap +msgid "More Advanced Uses of `make`" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:659 +msgid "" +"`Make` is a very powerful tool, and can do much more than the simple example " +"above shows. Unfortunately, there are several different versions of `make`, " +"and they all differ considerably. The best way to learn what they can do is " +"probably to read the documentation-hopefully this introduction will have " +"given you a base from which you can do this. The man:make[1] manual page " +"offers a comprehensive discussion of variables, arguments, and how to use " +"make." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:663 +msgid "" +"Many applications in the ports use GNU make, which has a very good set of " +"\"info\" pages. If you have installed any of these ports, GNU make will " +"automatically have been installed as `gmake`. It is also available as a " +"port and package in its own right." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:666 +msgid "" +"To view the info pages for GNU make, you will have to edit [.filename]#dir# " +"in the [.filename]#/usr/local/info# directory to add an entry for it. This " +"involves adding a line like" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:670 +#, no-wrap +msgid " * Make: (make). The GNU Make utility.\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:673 +msgid "" +"to the file. Once you have done this, you can type `info` and then select [." +"guimenuitem]#make# from the menu (or in Emacs, do `C-h i`)." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:675 +#, no-wrap +msgid "Debugging" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:677 +#, no-wrap +msgid "Introduction to Available Debuggers" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:682 +msgid "" +"Using a debugger allows running the program under more controlled " +"circumstances. Typically, it is possible to step through the program a line " +"at a time, inspect the value of variables, change them, tell the debugger to " +"run up to a certain point and then stop, and so on. It is also possible to " +"attach to a program that is already running, or load a core file to " +"investigate why the program crashed." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:685 +msgid "" +"This section is intended to be a quick introduction to using debuggers and " +"does not cover specialized topics such as debugging the kernel. For more " +"information about that, refer to crossref:kerneldebug[kerneldebug,Kernel " +"Debugging]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:689 +msgid "" +"The standard debugger supplied with FreeBSD is called `lldb` (LLVM " +"debugger). As it is part of the standard installation for that release, " +"there is no need to do anything special to use it. It has good command " +"help, accessible via the `help` command, as well as https://lldb.llvm.org/[a " +"web tutorial and documentation]." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:693 +msgid "" +"The `lldb` command is also available extref:{handbook}ports/[from ports or " +"packages, ports-using] as package:devel/llvm[]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:699 +msgid "" +"The other debugger available with FreeBSD is called `gdb` (GNU debugger). " +"Unlike lldb, it is not installed by default on FreeBSD; to use it, extref:" +"{handbook}#ports-using/[install] package:devel/gdb[] from ports or " +"packages. It has excellent on-line help, as well as a set of info pages." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:704 +msgid "" +"The two debuggers have a similar feature set, so which one to use is largely " +"a matter of taste. If familiar with one only, use that one. People " +"familiar with neither or both but wanting to use one from inside Emacs will " +"need to use `gdb` as `lldb` is unsupported by Emacs. Otherwise, try both " +"and see which one you prefer." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:705 +#, no-wrap +msgid "Using lldb" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:707 +#, no-wrap +msgid "Starting lldb" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:710 +msgid "Start up lldb by typing" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:714 +#, no-wrap +msgid "% lldb -- progname\n" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:716 +#, no-wrap +msgid "Running a Program with lldb" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:721 +msgid "" +"Compile the program with `-g` to get the most out of using `lldb`. It will " +"work without, but will only display the name of the function currently " +"running, instead of the source code. If it displays a line like:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:725 +#, no-wrap +msgid "Breakpoint 1: where = temp`main, address = …\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:728 +msgid "" +"(without an indication of source code filename and line number) when setting " +"a breakpoint, this means that the program was not compiled with `-g`." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:733 +msgid "" +"Most `lldb` commands have shorter forms that can be used instead. The " +"longer forms are used here for clarity." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:738 +msgid "" +"At the `lldb` prompt, type `breakpoint set -n main`. This will tell the " +"debugger not to display the preliminary set-up code in the program being run " +"and to stop execution at the beginning of the program's code. Now type " +"`process launch` to actually start the program- it will start at the " +"beginning of the set-up code and then get stopped by the debugger when it " +"calls `main()`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:742 +msgid "" +"To step through the program a line at a time, type `thread step-over`. When " +"the program gets to a function call, step into it by typing `thread step-" +"in`. Once in a function call, return from it by typing `thread step-out` or " +"use `up` and `down` to take a quick look at the caller." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:745 +msgid "" +"Here is a simple example of how to spot a mistake in a program with `lldb`. " +"This is our program (with a deliberate mistake):" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:749 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1023 +#, no-wrap +msgid "#include <stdio.h>\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:751 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1025 +#, no-wrap +msgid "int bazz(int anint);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:754 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1028 +#, no-wrap +msgid "" +"main() {\n" +"\tint i;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:759 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1033 +#, no-wrap +msgid "" +"\tprintf(\"This is my program\\n\");\n" +"\tbazz(i);\n" +"\treturn 0;\n" +"}\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:764 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1038 +#, no-wrap +msgid "" +"int bazz(int anint) {\n" +"\tprintf(\"You gave me %d\\n\", anint);\n" +"\treturn anint;\n" +"}\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:767 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1041 +msgid "" +"This program sets i to be `5` and passes it to a function `bazz()` which " +"prints out the number we gave it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:769 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1043 +msgid "Compiling and running the program displays" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:776 +#, no-wrap +msgid "" +"% cc -g -o temp temp.c\n" +"% ./temp\n" +"This is my program\n" +"anint = -5360\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:779 +msgid "That is not what was expected! Time to see what is going on!" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:790 +#, no-wrap +msgid "" +"% lldb -- temp\n" +"(lldb) target create \"temp\"\n" +"Current executable set to 'temp' (x86_64).\n" +"(lldb) breakpoint set -n main\t\t\t\tSkip the set-up code\n" +"Breakpoint 1: where = temp`main + 15 at temp.c:8:2, address = 0x00000000002012ef\tlldb puts breakpoint at main()\n" +"(lldb) process launch\t\t\t\t\tRun as far as main()\n" +"Process 9992 launching\n" +"Process 9992 launched: '/home/pauamma/tmp/temp' (x86_64)\tProgram starts running\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:824 +#, no-wrap +msgid "" +"Process 9992 stopped\n" +"* thread #1, name = 'temp', stop reason = breakpoint 1.1\tlldb stops at main()\n" +" frame #0: 0x00000000002012ef temp`main at temp.c:8:2\n" +" 5\tmain() {\n" +" 6\t\tint i;\n" +" 7\n" +"-> 8\t\tprintf(\"This is my program\\n\");\t\t\tIndicates the line where it stopped\n" +" 9\t\tbazz(i);\n" +" 10\t\treturn 0;\n" +" 11\t}\n" +"(lldb) thread step-over\t\t\tGo to next line\n" +"This is my program\t\t\t\t\t\tProgram prints out\n" +"Process 9992 stopped\n" +"* thread #1, name = 'temp', stop reason = step over\n" +" frame #0: 0x0000000000201300 temp`main at temp.c:9:7\n" +" 6\t\tint i;\n" +" 7\n" +" 8\t\tprintf(\"This is my program\\n\");\n" +"-> 9\t\tbazz(i);\n" +" 10\t\treturn 0;\n" +" 11\t}\n" +" 12\n" +"(lldb) thread step-in\t\t\tstep into bazz()\n" +"Process 9992 stopped\n" +"* thread #1, name = 'temp', stop reason = step in\n" +" frame #0: 0x000000000020132b temp`bazz(anint=-5360) at temp.c:14:29\tlldb displays stack frame\n" +" 11\t}\n" +" 12\n" +" 13\tint bazz(int anint) {\n" +"-> 14\t\tprintf(\"You gave me %d\\n\", anint);\n" +" 15\t\treturn anint;\n" +" 16\t}\n" +"(lldb)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:827 +msgid "" +"Hang on a minute! How did anint get to be `-5360`? Was it not set to `5` in " +"`main()`? Let us move up to `main()` and have a look." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:841 +#, no-wrap +msgid "" +"(lldb) up\t\tMove up call stack\n" +"frame #1: 0x000000000020130b temp`main at temp.c:9:2\t\tlldb displays stack frame\n" +" 6\t\tint i;\n" +" 7\n" +" 8\t\tprintf(\"This is my program\\n\");\n" +"-> 9\t\tbazz(i);\n" +" 10\t\treturn 0;\n" +" 11\t}\n" +" 12\n" +"(lldb) frame variable i\t\t\tShow us the value of i\n" +"(int) i = -5360\t\t\t\t\t\t\tlldb displays -5360\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:845 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1086 +msgid "" +"Oh dear! Looking at the code, we forgot to initialize i. We meant to put" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:851 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1092 +#, no-wrap +msgid "" +"...\n" +"main() {\n" +"\tint i;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:855 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1096 +#, no-wrap +msgid "" +"\ti = 5;\n" +"\tprintf(\"This is my program\\n\");\n" +"...\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:860 +msgid "" +"but we left the `i=5;` line out. As we did not initialize i, it had " +"whatever number happened to be in that area of memory when the program ran, " +"which in this case happened to be `-5360`." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:866 +msgid "" +"The `lldb` command displays the stack frame every time we go into or out of " +"a function, even if we are using `up` and `down` to move around the call " +"stack. This shows the name of the function and the values of its arguments, " +"which helps us keep track of where we are and what is going on. (The stack " +"is a storage area where the program stores information about the arguments " +"passed to functions and where to go when it returns from a function call.)" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:868 +#, no-wrap +msgid "Examining a Core File with lldb" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:873 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1114 +msgid "" +"A core file is basically a file which contains the complete state of the " +"process when it crashed. In \"the good old days\", programmers had to print " +"out hex listings of core files and sweat over machine code manuals, but now " +"life is a bit easier. Incidentally, under FreeBSD and other 4.4BSD systems, " +"a core file is called [.filename]#progname.core# instead of just [." +"filename]#core#, to make it clearer which program a core file belongs to." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:876 +msgid "" +"To examine a core file, specify the name of the core file in addition to the " +"program itself. Instead of starting up `lldb` in the usual way, type `lldb -" +"c _progname_.core \\-- _progname_`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:878 +msgid "The debugger will display something like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:885 +#, no-wrap +msgid "" +"% lldb -c [.filename]#progname.core# -- [.filename]#progname#\n" +"(lldb) target create \"[.filename]#progname#\" --core \"[.filename]#progname#.core\"\n" +"Core file '/home/pauamma/tmp/[.filename]#progname.core#' (x86_64) was loaded.\n" +"(lldb)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:891 +msgid "" +"In this case, the program was called [.filename]#progname#, so the core file " +"is called [.filename]#progname.core#. The debugger does not display why the " +"program crashed or where. For this, use `thread backtrace all`. This will " +"also show how the function where the program dumped core was called." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:900 +#, no-wrap +msgid "" +"(lldb) thread backtrace all\n" +"* thread #1, name = 'progname', stop reason = signal SIGSEGV\n" +" * frame #0: 0x0000000000201347 progname`bazz(anint=5) at temp2.c:17:10\n" +" frame #1: 0x0000000000201312 progname`main at temp2.c:10:2\n" +" frame #2: 0x000000000020110f progname`_start(ap=<unavailable>, cleanup=<unavailable>) at crt1.c:76:7\n" +"(lldb)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:905 +msgid "" +"`SIGSEGV` indicates that the program tried to access memory (run code or " +"read/write data usually) at a location that does not belong to it, but does " +"not give any specifics. For that, look at the source code at line 10 of " +"file temp2.c, in `bazz()`. The backtrace also says that in this case, " +"`bazz()` was called from `main()`." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:906 +#, no-wrap +msgid "Attaching to a Running Program with lldb" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:911 +msgid "" +"One of the neatest features about `lldb` is that it can attach to a program " +"that is already running. Of course, that requires sufficient permissions to " +"do so. A common problem is stepping through a program that forks and " +"wanting to trace the child, but the debugger will only trace the parent." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:913 +msgid "" +"To do that, start up another `lldb`, use `ps` to find the process ID for the " +"child, and do" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:917 +#, no-wrap +msgid "(lldb) process attach -p pid\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:920 +msgid "in `lldb`, and then debug as usual." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:922 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1177 +msgid "" +"For that to work well, the code that calls `fork` to create the child needs " +"to do something like the following (courtesy of the `gdb` info pages):" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:930 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1185 +#, no-wrap +msgid "" +"...\n" +"if ((pid = fork()) < 0)\t\t/* _Always_ check this */\n" +"\terror();\n" +"else if (pid == 0) {\t\t/* child */\n" +"\tint PauseMode = 1;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:936 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1191 +#, no-wrap +msgid "" +"\twhile (PauseMode)\n" +"\t\tsleep(10);\t/* Wait until someone attaches to us */\n" +"\t...\n" +"} else {\t\t\t/* parent */\n" +"\t...\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:939 +msgid "" +"Now all that is needed is to attach to the child, set PauseMode to `0` with " +"`expr PauseMode = 0` and wait for the `sleep()` call to return." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:940 +#, no-wrap +msgid "Remote Debugging Using LLDB" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:946 +msgid "" +"The described functionality is available starting with LLDB version 12.0.0. " +"Users of FreeBSD releases containing an earlier LLDB version may wish to use " +"the snapshot available in extref:{handbook}[ports or packages, ports-using], " +"as package:devel/llvm-devel[]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:950 +msgid "" +"Starting with LLDB 12.0.0, remote debugging is supported on FreeBSD. This " +"means that `lldb-server` can be started to debug a program on one host, " +"while the interactive `lldb` client connects to it from another one." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:952 +msgid "" +"To launch a new process to be debugged remotely, run `lldb-server` on the " +"remote server by typing" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:956 +#, no-wrap +msgid "% lldb-server g host:port -- progname\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:959 +msgid "" +"The process will be stopped immediately after launching, and `lldb-server` " +"will wait for the client to connect." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:961 +msgid "" +"Start `lldb` locally and type the following command to connect to the remote " +"server:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:965 +#, no-wrap +msgid "(lldb) gdb-remote host:port\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:969 +msgid "" +"`lldb-server` can also attach to a running process. To do that, type the " +"following on the remote server:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:973 +#, no-wrap +msgid "% lldb-server g host:port --attach pid-or-name\n" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:975 +#, no-wrap +msgid "Using gdb" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:977 +#, no-wrap +msgid "Starting gdb" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:980 +msgid "Start up gdb by typing" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:984 +#, no-wrap +msgid "% gdb progname\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:988 +msgid "although many people prefer to run it inside Emacs. To do this, type:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:992 +#, no-wrap +msgid " M-x gdb RET progname RET\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:995 +msgid "" +"Finally, for those finding its text-based command-prompt style off-putting, " +"there is a graphical front-end for it (package:devel/xxgdb[]) in the Ports " +"Collection." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:996 +#, no-wrap +msgid "Running a Program with gdb" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1001 +msgid "" +"Compile the program with `-g` to get the most out of using `gdb`. It will " +"work without, but will only display the name of the function currently " +"running, instead of the source code. A line like:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1005 +#, no-wrap +msgid "... (no debugging symbols found) ...\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1008 +msgid "when `gdb` starts up means that the program was not compiled with `-g`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1012 +msgid "" +"At the `gdb` prompt, type `break main`. This will tell the debugger to skip " +"the preliminary set-up code in the program being run and to stop execution " +"at the beginning of the program's code. Now type `run` to start the " +"program- it will start at the beginning of the set-up code and then get " +"stopped by the debugger when it calls `main()`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1016 +msgid "" +"To step through the program a line at a time, press `n`. When at a function " +"call, step into it by pressing `s`. Once in a function call, return from it " +"by pressing `f`, or use `up` and `down` to take a quick look at the caller." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1019 +msgid "" +"Here is a simple example of how to spot a mistake in a program with `gdb`. " +"This is our program (with a deliberate mistake):" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1050 +#, no-wrap +msgid "" +"% cc -g -o temp temp.c\n" +"% ./temp\n" +"This is my program\n" +"anint = 4231\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1053 +msgid "That was not what we expected! Time to see what is going on!" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1065 +#, no-wrap +msgid "" +"% gdb temp\n" +"GDB is free software and you are welcome to distribute copies of it\n" +" under certain conditions; type \"show copying\" to see the conditions.\n" +"There is absolutely no warranty for GDB; type \"show warranty\" for details.\n" +"GDB 4.13 (i386-unknown-freebsd), Copyright 1994 Free Software Foundation, Inc.\n" +"(gdb) break main\t\t\t\tSkip the set-up code\n" +"Breakpoint 1 at 0x160f: file temp.c, line 9.\tgdb puts breakpoint at main()\n" +"(gdb) run\t\t\t\t\tRun as far as main()\n" +"Starting program: /home/james/tmp/temp\t\tProgram starts running\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1072 +#, no-wrap +msgid "" +"Breakpoint 1, main () at temp.c:9\t\tgdb stops at main()\n" +"(gdb) n\t\t\t\t\t\tGo to next line\n" +"This is my program\t\t\t\tProgram prints out\n" +"(gdb) s\t\t\t\t\t\tstep into bazz()\n" +"bazz (anint=4231) at temp.c:17\t\t\tgdb displays stack frame\n" +"(gdb)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1075 +msgid "" +"Hang on a minute! How did anint get to be `4231`? Was it not set to `5` in " +"`main()`? Let us move up to `main()` and have a look." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1082 +#, no-wrap +msgid "" +"(gdb) up\t\t\t\t\tMove up call stack\n" +"#1 0x1625 in main () at temp.c:11\t\tgdb displays stack frame\n" +"(gdb) p i\t\t\t\t\tShow us the value of i\n" +"$1 = 4231\t\t\t\t\tgdb displays 4231\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1101 +msgid "" +"but we left the `i=5;` line out. As we did not initialize i, it had " +"whatever number happened to be in that area of memory when the program ran, " +"which in this case happened to be `4231`." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1107 +msgid "" +"The `gdb` command displays the stack frame every time we go into or out of a " +"function, even if we are using `up` and `down` to move around the call " +"stack. This shows the name of the function and the values of its arguments, " +"which helps us keep track of where we are and what is going on. (The stack " +"is a storage area where the program stores information about the arguments " +"passed to functions and where to go when it returns from a function call.)" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1109 +#, no-wrap +msgid "Examining a Core File with gdb" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1117 +msgid "" +"To examine a core file, start up `gdb` in the usual way. Instead of typing " +"`break` or `run`, type" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1121 +#, no-wrap +msgid "(gdb) core progname.core\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1124 +msgid "" +"If the core file is not in the current directory, type `dir /path/to/core/" +"file` first." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1126 +msgid "The debugger should display something like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1140 +#, no-wrap +msgid "" +"% gdb [.filename]#progname#\n" +"GDB is free software and you are welcome to distribute copies of it\n" +" under certain conditions; type \"show copying\" to see the conditions.\n" +"There is absolutely no warranty for GDB; type \"show warranty\" for details.\n" +"GDB 4.13 (i386-unknown-freebsd), Copyright 1994 Free Software Foundation, Inc.\n" +"(gdb) core [.filename]#progname.core#\n" +"Core was generated by `[.filename]#progname#'.\n" +"Program terminated with signal 11, Segmentation fault.\n" +"Cannot access memory at address 0x7020796d.\n" +"#0 0x164a in bazz (anint=0x5) at temp.c:17\n" +"(gdb)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1144 +msgid "" +"In this case, the program was called [.filename]#progname#, so the core file " +"is called [.filename]#progname.core#. We can see that the program crashed " +"due to trying to access an area in memory that was not available to it in a " +"function called `bazz`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1148 +msgid "" +"Sometimes it is useful to be able to see how a function was called, as the " +"problem could have occurred a long way up the call stack in a complex " +"program. `bt` causes `gdb` to print out a back-trace of the call stack:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1156 +#, no-wrap +msgid "" +"(gdb) bt\n" +"#0 0x164a in bazz (anint=0x5) at temp.c:17\n" +"#1 0xefbfd888 in end ()\n" +"#2 0x162c in main () at temp.c:11\n" +"(gdb)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1160 +msgid "" +"The `end()` function is called when a program crashes; in this case, the " +"`bazz()` function was called from `main()`." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1161 +#, no-wrap +msgid "Attaching to a Running Program with gdb" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1166 +msgid "" +"One of the neatest features about `gdb` is that it can attach to a program " +"that is already running. Of course, that requires sufficient permissions to " +"do so. A common problem is stepping through a program that forks and " +"wanting to trace the child, but the debugger will only trace the parent." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1168 +msgid "" +"To do that, start up another `gdb`, use `ps` to find the process ID for the " +"child, and do" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1172 +#, no-wrap +msgid "(gdb) attach pid\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1175 +msgid "in `gdb`, and then debug as usual." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1194 +msgid "" +"Now all that is needed is to attach to the child, set PauseMode to `0`, and " +"wait for the `sleep()` call to return!" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1196 +#, no-wrap +msgid "Using Emacs as a Development Environment" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1198 +#, no-wrap +msgid "Emacs" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1202 +msgid "" +"Emacs is a highly customizable editor-indeed, it has been customized to the " +"point where it is more like an operating system than an editor! Many " +"developers and sysadmins do in fact spend practically all their time working " +"inside Emacs, leaving it only to log out." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1204 +msgid "" +"It is impossible even to summarize everything Emacs can do here, but here " +"are some of the features of interest to developers:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1206 +msgid "" +"Very powerful editor, allowing search-and-replace on both strings and " +"regular expressions (patterns), jumping to start/end of block expression, " +"etc, etc." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1207 +msgid "Pull-down menus and online help." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1208 +msgid "Language-dependent syntax highlighting and indentation." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1209 +msgid "Completely customizable." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1210 +msgid "You can compile and debug programs within Emacs." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1211 +msgid "" +"On a compilation error, you can jump to the offending line of source code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1212 +msgid "" +"Friendly-ish front-end to the `info` program used for reading GNU hypertext " +"documentation, including the documentation on Emacs itself." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1213 +msgid "" +"Friendly front-end to `gdb`, allowing you to look at the source code as you " +"step through your program." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1215 +msgid "And doubtless many more that have been overlooked." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1217 +msgid "" +"Emacs can be installed on FreeBSD using the package:editors/emacs[] port." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1220 +msgid "" +"Once it is installed, start it up and do `C-h t` to read an Emacs tutorial-" +"that means hold down kbd:[control], press kbd:[h], let go of kbd:[control], " +"and then press kbd:[t]. (Alternatively, you can use the mouse to select [." +"guimenuitem]#Emacs Tutorial# from the menu:Help[] menu.)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1225 +msgid "" +"Although Emacs does have menus, it is well worth learning the key bindings, " +"as it is much quicker when you are editing something to press a couple of " +"keys than to try to find the mouse and then click on the right place. And, " +"when you are talking to seasoned Emacs users, you will find they often " +"casually throw around expressions like \"`M-x replace-s RET foo RET bar " +"RET`\" so it is useful to know what they mean. And in any case, Emacs has " +"far too many useful functions for them to all fit on the menu bars." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1229 +msgid "" +"Fortunately, it is quite easy to pick up the key-bindings, as they are " +"displayed next to the menu item. My advice is to use the menu item for, " +"say, opening a file until you understand how it works and feel confident " +"with it, then try doing C-x C-f. When you are happy with that, move on to " +"another menu command." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1232 +msgid "" +"If you cannot remember what a particular combination of keys does, select [." +"guimenuitem]#Describe Key# from the menu:Help[] menu and type it in-Emacs " +"will tell you what it does. You can also use the [.guimenuitem]#Command " +"Apropos# menu item to find out all the commands which contain a particular " +"word in them, with the key binding next to it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1235 +msgid "" +"By the way, the expression above means hold down the kbd:[Meta] key, press " +"kbd:[x], release the kbd:[Meta] key, type `replace-s` (short for `replace-" +"string`-another feature of Emacs is that you can abbreviate commands), press " +"the kbd:[return] key, type `foo` (the string you want replaced), press the " +"kbd:[return] key, type bar (the string you want to replace `foo` with) and " +"press kbd:[return] again. Emacs will then do the search-and-replace " +"operation you have just requested." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1238 +msgid "" +"If you are wondering what on earth kbd:[Meta] is, it is a special key that " +"many UNIX(R) workstations have. Unfortunately, PC's do not have one, so it " +"is usually kbd:[alt] (or if you are unlucky, the kbd:[escape] key)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1242 +msgid "" +"Oh, and to get out of Emacs, do `C-x C-c` (that means hold down the kbd:" +"[control] key, press kbd:[x], press kbd:[c] and release the kbd:[control] " +"key). If you have any unsaved files open, Emacs will ask you if you want to " +"save them. (Ignore the bit in the documentation where it says `C-z` is the " +"usual way to leave Emacs-that leaves Emacs hanging around in the background, " +"and is only really useful if you are on a system which does not have virtual " +"terminals)." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1243 +#, no-wrap +msgid "Configuring Emacs" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1246 +msgid "" +"Emacs does many wonderful things; some of them are built in, some of them " +"need to be configured." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1250 +msgid "" +"Instead of using a proprietary macro language for configuration, Emacs uses " +"a version of Lisp specially adapted for editors, known as Emacs Lisp. " +"Working with Emacs Lisp can be quite helpful if you want to go on and learn " +"something like Common Lisp. Emacs Lisp has many features of Common Lisp, " +"although it is considerably smaller (and thus easier to master)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1252 +msgid "" +"The best way to learn Emacs Lisp is to download the link:ftp://ftp.gnu.org/" +"old-gnu/emacs/elisp-manual-19-2.4.tar.gz[Emacs Tutorial]" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1257 +msgid "" +"However, there is no need to actually know any Lisp to get started with " +"configuring Emacs, as I have included a sample [.filename]#.emacs#, which " +"should be enough to get you started. Just copy it into your home directory " +"and restart Emacs if it is already running; it will read the commands from " +"the file and (hopefully) give you a useful basic setup." +msgstr "" + +#. type: Block title +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1258 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1276 +#, no-wrap +msgid "A Sample [.filename]#.emacs#" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1261 +msgid "" +"Unfortunately, there is far too much here to explain it in detail; however " +"there are one or two points worth mentioning." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1263 +msgid "Everything beginning with a `;` is a comment and is ignored by Emacs." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1264 +msgid "" +"In the first line, the `-*- Emacs-Lisp -*-` is so that we can edit [." +"filename]#.emacs# itself within Emacs and get all the fancy features for " +"editing Emacs Lisp. Emacs usually tries to guess this based on the filename, " +"and may not get it right for [.filename]#.emacs#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1265 +msgid "" +"The kbd:[tab] key is bound to an indentation function in some modes, so when " +"you press the tab key, it will indent the current line of code. If you want " +"to put a tab character in whatever you are writing, hold the kbd:[control] " +"key down while you are pressing the kbd:[tab] key." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1266 +msgid "" +"This file supports syntax highlighting for C, C++, Perl, Lisp and Scheme, by " +"guessing the language from the filename." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1267 +msgid "" +"Emacs already has a pre-defined function called `next-error`. In a " +"compilation output window, this allows you to move from one compilation " +"error to the next by doing `M-n`; we define a complementary function, " +"`previous-error`, that allows you to go to a previous error by doing `M-p`. " +"The nicest feature of all is that `C-c C-c` will open up the source file in " +"which the error occurred and jump to the appropriate line." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1268 +msgid "" +"We enable Emacs's ability to act as a server, so that if you are doing " +"something outside Emacs and you want to edit a file, you can just type in" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1272 +#, no-wrap +msgid "% emacsclient filename\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1275 +msgid "" +"and then you can edit the file in your Emacs!footnote:[Many Emacs users set " +"their EDITOR environment to emacsclient so this happens every time they need " +"to edit a file.]" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1281 +#, no-wrap +msgid ";; -*-Emacs-Lisp-*-\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1286 +#, no-wrap +msgid "" +";; This file is designed to be re-evaled; use the variable first-time\n" +";; to avoid any problems with this.\n" +"(defvar first-time t\n" +" \"Flag signifying this is the first time that .emacs has been evaled\")\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1294 +#, no-wrap +msgid "" +";; Meta\n" +"(global-set-key \"\\M- \" 'set-mark-command)\n" +"(global-set-key \"\\M-\\C-h\" 'backward-kill-word)\n" +"(global-set-key \"\\M-\\C-r\" 'query-replace)\n" +"(global-set-key \"\\M-r\" 'replace-string)\n" +"(global-set-key \"\\M-g\" 'goto-line)\n" +"(global-set-key \"\\M-h\" 'help-command)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1315 +#, no-wrap +msgid "" +";; Function keys\n" +"(global-set-key [f1] 'manual-entry)\n" +"(global-set-key [f2] 'info)\n" +"(global-set-key [f3] 'repeat-complex-command)\n" +"(global-set-key [f4] 'advertised-undo)\n" +"(global-set-key [f5] 'eval-current-buffer)\n" +"(global-set-key [f6] 'buffer-menu)\n" +"(global-set-key [f7] 'other-window)\n" +"(global-set-key [f8] 'find-file)\n" +"(global-set-key [f9] 'save-buffer)\n" +"(global-set-key [f10] 'next-error)\n" +"(global-set-key [f11] 'compile)\n" +"(global-set-key [f12] 'grep)\n" +"(global-set-key [C-f1] 'compile)\n" +"(global-set-key [C-f2] 'grep)\n" +"(global-set-key [C-f3] 'next-error)\n" +"(global-set-key [C-f4] 'previous-error)\n" +"(global-set-key [C-f5] 'display-faces)\n" +"(global-set-key [C-f8] 'dired)\n" +"(global-set-key [C-f10] 'kill-compilation)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1333 +#, no-wrap +msgid "" +";; Keypad bindings\n" +"(global-set-key [up] \"\\C-p\")\n" +"(global-set-key [down] \"\\C-n\")\n" +"(global-set-key [left] \"\\C-b\")\n" +"(global-set-key [right] \"\\C-f\")\n" +"(global-set-key [home] \"\\C-a\")\n" +"(global-set-key [end] \"\\C-e\")\n" +"(global-set-key [prior] \"\\M-v\")\n" +"(global-set-key [next] \"\\C-v\")\n" +"(global-set-key [C-up] \"\\M-\\C-b\")\n" +"(global-set-key [C-down] \"\\M-\\C-f\")\n" +"(global-set-key [C-left] \"\\M-b\")\n" +"(global-set-key [C-right] \"\\M-f\")\n" +"(global-set-key [C-home] \"\\M-<\")\n" +"(global-set-key [C-end] \"\\M->\")\n" +"(global-set-key [C-prior] \"\\M-<\")\n" +"(global-set-key [C-next] \"\\M->\")\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1336 +#, no-wrap +msgid "" +";; Mouse\n" +"(global-set-key [mouse-3] 'imenu)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1340 +#, no-wrap +msgid "" +";; Misc\n" +"(global-set-key [C-tab] \"\\C-q\\t\")\t; Control tab quotes a tab.\n" +"(setq backup-by-copying-when-mismatch t)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1345 +#, no-wrap +msgid "" +";; Treat 'y' or <CR> as yes, 'n' as no.\n" +"(fset 'yes-or-no-p 'y-or-n-p)\n" +"(define-key query-replace-map [return] 'act)\n" +"(define-key query-replace-map [?\\C-m] 'act)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1349 +#, no-wrap +msgid "" +";; Load packages\n" +"(require 'desktop)\n" +"(require 'tar-mode)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1355 +#, no-wrap +msgid "" +";; Pretty diff mode\n" +"(autoload 'ediff-buffers \"ediff\" \"Intelligent Emacs interface to diff\" t)\n" +"(autoload 'ediff-files \"ediff\" \"Intelligent Emacs interface to diff\" t)\n" +"(autoload 'ediff-files-remote \"ediff\"\n" +" \"Intelligent Emacs interface to diff\")\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1364 +#, no-wrap +msgid "" +"(if first-time\n" +" (setq auto-mode-alist\n" +"\t (append '((\"\\\\.cpp$\" . c++-mode)\n" +"\t\t (\"\\\\.hpp$\" . c++-mode)\n" +"\t\t (\"\\\\.lsp$\" . lisp-mode)\n" +"\t\t (\"\\\\.scm$\" . scheme-mode)\n" +"\t\t (\"\\\\.pl$\" . perl-mode)\n" +"\t\t ) auto-mode-alist)))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1369 +#, no-wrap +msgid "" +";; Auto font lock mode\n" +"(defvar font-lock-auto-mode-list\n" +" (list 'c-mode 'c++-mode 'c++-c-mode 'emacs-lisp-mode 'lisp-mode 'perl-mode 'scheme-mode)\n" +" \"List of modes to always start in font-lock-mode\")\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1374 +#, no-wrap +msgid "" +"(defvar font-lock-mode-keyword-alist\n" +" '((c++-c-mode . c-font-lock-keywords)\n" +" (perl-mode . perl-font-lock-keywords))\n" +" \"Associations between modes and keywords\")\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1382 +#, no-wrap +msgid "" +"(defun font-lock-auto-mode-select ()\n" +" \"Automatically select font-lock-mode if the current major mode is in font-lock-auto-mode-list\"\n" +" (if (memq major-mode font-lock-auto-mode-list)\n" +" (progn\n" +"\t(font-lock-mode t))\n" +" )\n" +" )\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1384 +#, no-wrap +msgid "(global-set-key [M-f1] 'font-lock-fontify-buffer)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1401 +#, no-wrap +msgid "" +";; New dabbrev stuff\n" +";(require 'new-dabbrev)\n" +"(setq dabbrev-always-check-other-buffers t)\n" +"(setq dabbrev-abbrev-char-regexp \"\\\\sw\\\\|\\\\s_\")\n" +"(add-hook 'emacs-lisp-mode-hook\n" +"\t '(lambda ()\n" +"\t (set (make-local-variable 'dabbrev-case-fold-search) nil)\n" +"\t (set (make-local-variable 'dabbrev-case-replace) nil)))\n" +"(add-hook 'c-mode-hook\n" +"\t '(lambda ()\n" +"\t (set (make-local-variable 'dabbrev-case-fold-search) nil)\n" +"\t (set (make-local-variable 'dabbrev-case-replace) nil)))\n" +"(add-hook 'text-mode-hook\n" +"\t '(lambda ()\n" +"\t (set (make-local-variable 'dabbrev-case-fold-search) t)\n" +"\t (set (make-local-variable 'dabbrev-case-replace) t)))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1413 +#, no-wrap +msgid "" +";; C++ and C mode...\n" +"(defun my-c++-mode-hook ()\n" +" (setq tab-width 4)\n" +" (define-key c++-mode-map \"\\C-m\" 'reindent-then-newline-and-indent)\n" +" (define-key c++-mode-map \"\\C-ce\" 'c-comment-edit)\n" +" (setq c++-auto-hungry-initial-state 'none)\n" +" (setq c++-delete-function 'backward-delete-char)\n" +" (setq c++-tab-always-indent t)\n" +" (setq c-indent-level 4)\n" +" (setq c-continued-statement-offset 4)\n" +" (setq c++-empty-arglist-indent 4))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1427 +#, no-wrap +msgid "" +"(defun my-c-mode-hook ()\n" +" (setq tab-width 4)\n" +" (define-key c-mode-map \"\\C-m\" 'reindent-then-newline-and-indent)\n" +" (define-key c-mode-map \"\\C-ce\" 'c-comment-edit)\n" +" (setq c-auto-hungry-initial-state 'none)\n" +" (setq c-delete-function 'backward-delete-char)\n" +" (setq c-tab-always-indent t)\n" +";; BSD-ish indentation style\n" +" (setq c-indent-level 4)\n" +" (setq c-continued-statement-offset 4)\n" +" (setq c-brace-offset -4)\n" +" (setq c-argdecl-indent 0)\n" +" (setq c-label-offset -4))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1434 +#, no-wrap +msgid "" +";; Perl mode\n" +"(defun my-perl-mode-hook ()\n" +" (setq tab-width 4)\n" +" (define-key c++-mode-map \"\\C-m\" 'reindent-then-newline-and-indent)\n" +" (setq perl-indent-level 4)\n" +" (setq perl-continued-statement-offset 4))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1438 +#, no-wrap +msgid "" +";; Scheme mode...\n" +"(defun my-scheme-mode-hook ()\n" +" (define-key scheme-mode-map \"\\C-m\" 'reindent-then-newline-and-indent))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1444 +#, no-wrap +msgid "" +";; Emacs-Lisp mode...\n" +"(defun my-lisp-mode-hook ()\n" +" (define-key lisp-mode-map \"\\C-m\" 'reindent-then-newline-and-indent)\n" +" (define-key lisp-mode-map \"\\C-i\" 'lisp-indent-line)\n" +" (define-key lisp-mode-map \"\\C-j\" 'eval-print-last-sexp))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1452 +#, no-wrap +msgid "" +";; Add all of the hooks...\n" +"(add-hook 'c++-mode-hook 'my-c++-mode-hook)\n" +"(add-hook 'c-mode-hook 'my-c-mode-hook)\n" +"(add-hook 'scheme-mode-hook 'my-scheme-mode-hook)\n" +"(add-hook 'emacs-lisp-mode-hook 'my-lisp-mode-hook)\n" +"(add-hook 'lisp-mode-hook 'my-lisp-mode-hook)\n" +"(add-hook 'perl-mode-hook 'my-perl-mode-hook)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1458 +#, no-wrap +msgid "" +";; Complement to next-error\n" +"(defun previous-error (n)\n" +" \"Visit previous compilation error message and corresponding source code.\"\n" +" (interactive \"p\")\n" +" (next-error (- n)))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1471 +#, no-wrap +msgid "" +";; Misc...\n" +"(transient-mark-mode 1)\n" +"(setq mark-even-if-inactive t)\n" +"(setq visible-bell nil)\n" +"(setq next-line-add-newlines nil)\n" +"(setq compile-command \"make\")\n" +"(setq suggest-key-bindings nil)\n" +"(put 'eval-expression 'disabled nil)\n" +"(put 'narrow-to-region 'disabled nil)\n" +"(put 'set-goal-column 'disabled nil)\n" +"(if (>= emacs-major-version 21)\n" +"\t(setq show-trailing-whitespace t))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1477 +#, no-wrap +msgid "" +";; Elisp archive searching\n" +"(autoload 'format-lisp-code-directory \"lispdir\" nil t)\n" +"(autoload 'lisp-dir-apropos \"lispdir\" nil t)\n" +"(autoload 'lisp-dir-retrieve \"lispdir\" nil t)\n" +"(autoload 'lisp-dir-verify \"lispdir\" nil t)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1486 +#, no-wrap +msgid "" +";; Font lock mode\n" +"(defun my-make-face (face color &optional bold)\n" +" \"Create a face from a color and optionally make it bold\"\n" +" (make-face face)\n" +" (copy-face 'default face)\n" +" (set-face-foreground face color)\n" +" (if bold (make-face-bold face))\n" +" )\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1499 +#, no-wrap +msgid "" +"(if (eq window-system 'x)\n" +" (progn\n" +" (my-make-face 'blue \"blue\")\n" +" (my-make-face 'red \"red\")\n" +" (my-make-face 'green \"dark green\")\n" +" (setq font-lock-comment-face 'blue)\n" +" (setq font-lock-string-face 'bold)\n" +" (setq font-lock-type-face 'bold)\n" +" (setq font-lock-keyword-face 'bold)\n" +" (setq font-lock-function-name-face 'red)\n" +" (setq font-lock-doc-string-face 'green)\n" +" (add-hook 'find-file-hooks 'font-lock-auto-mode-select)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1507 +#, no-wrap +msgid "" +" (setq baud-rate 1000000)\n" +" (global-set-key \"\\C-cmm\" 'menu-bar-mode)\n" +" (global-set-key \"\\C-cms\" 'scroll-bar-mode)\n" +" (global-set-key [backspace] 'backward-delete-char)\n" +"\t\t\t\t\t; (global-set-key [delete] 'delete-char)\n" +" (standard-display-european t)\n" +" (load-library \"iso-transl\")))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1524 +#, no-wrap +msgid "" +";; X11 or PC using direct screen writes\n" +"(if window-system\n" +" (progn\n" +" ;; (global-set-key [M-f1] 'hilit-repaint-command)\n" +" ;; (global-set-key [M-f2] [?\\C-u M-f1])\n" +" (setq hilit-mode-enable-list\n" +"\t '(not text-mode c-mode c++-mode emacs-lisp-mode lisp-mode\n" +"\t\t scheme-mode)\n" +"\t hilit-auto-highlight nil\n" +"\t hilit-auto-rehighlight 'visible\n" +"\t hilit-inhibit-hooks nil\n" +"\t hilit-inhibit-rebinding t)\n" +" (require 'hilit19)\n" +" (require 'paren))\n" +" (setq baud-rate 2400)\t\t\t; For slow serial connections\n" +" )\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1533 +#, no-wrap +msgid "" +";; TTY type terminal\n" +"(if (and (not window-system)\n" +"\t (not (equal system-type 'ms-dos)))\n" +" (progn\n" +" (if first-time\n" +"\t (progn\n" +"\t (keyboard-translate ?\\C-h ?\\C-?)\n" +"\t (keyboard-translate ?\\C-? ?\\C-h)))))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1539 +#, no-wrap +msgid "" +";; Under UNIX\n" +"(if (not (equal system-type 'ms-dos))\n" +" (progn\n" +" (if first-time\n" +"\t (server-start))))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1547 +#, no-wrap +msgid "" +";; Add any face changes here\n" +"(add-hook 'term-setup-hook 'my-term-setup-hook)\n" +"(defun my-term-setup-hook ()\n" +" (if (eq window-system 'pc)\n" +" (progn\n" +";;\t(set-face-background 'default \"red\")\n" +"\t)))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1553 +#, no-wrap +msgid "" +";; Restore the \"desktop\" - do this as late as possible\n" +"(if first-time\n" +" (progn\n" +" (desktop-load-default)\n" +" (desktop-read)))\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1556 +#, no-wrap +msgid "" +";; Indicate that this file has been read at least once\n" +"(setq first-time nil)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1558 +#, no-wrap +msgid ";; No need to debug anything now\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1560 +#, no-wrap +msgid "(setq debug-on-error nil)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1563 +#, no-wrap +msgid "" +";; All done\n" +"(message \"All done, %s%s\" (user-login-name) \".\")\n" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1566 +#, no-wrap +msgid "Extending the Range of Languages Emacs Understands" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1569 +msgid "" +"Now, this is all very well if you only want to program in the languages " +"already catered for in [.filename]#.emacs# (C, C++, Perl, Lisp and Scheme), " +"but what happens if a new language called \"whizbang\" comes out, full of " +"exciting features?" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1573 +msgid "" +"The first thing to do is find out if whizbang comes with any files that tell " +"Emacs about the language. These usually end in [.filename]#.el#, short for " +"\"Emacs Lisp\". For example, if whizbang is a FreeBSD port, we can locate " +"these files by doing" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1577 +#, no-wrap +msgid "% find /usr/ports/lang/whizbang -name \"*.el\" -print\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1581 +msgid "" +"and install them by copying them into the Emacs site Lisp directory. On " +"FreeBSD, this is [.filename]#/usr/local/share/emacs/site-lisp#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1583 +msgid "So for example, if the output from the find command was" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1587 +#, no-wrap +msgid "/usr/ports/lang/whizbang/work/misc/whizbang.el\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1590 +msgid "we would do" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1594 +#, no-wrap +msgid "# cp /usr/ports/lang/whizbang/work/misc/whizbang.el /usr/local/share/emacs/site-lisp\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1599 +msgid "" +"Next, we need to decide what extension whizbang source files have. Let us " +"say for the sake of argument that they all end in [.filename]#.wiz#. We " +"need to add an entry to our [.filename]#.emacs# to make sure Emacs will be " +"able to use the information in [.filename]#whizbang.el#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1601 +msgid "" +"Find the auto-mode-alist entry in [.filename]#.emacs# and add a line for " +"whizbang, such as:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1609 +#, no-wrap +msgid "" +"...\n" +"(\"\\\\.lsp$\" . lisp-mode)\n" +"(\"\\\\.wiz$\" . whizbang-mode)\n" +"(\"\\\\.scm$\" . scheme-mode)\n" +"...\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1612 +msgid "" +"This means that Emacs will automatically go into `whizbang-mode` when you " +"edit a file ending in [.filename]#.wiz#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1615 +msgid "" +"Just below this, you will find the font-lock-auto-mode-list entry. Add " +"`whizbang-mode` to it like so:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1622 +#, no-wrap +msgid "" +";; Auto font lock mode\n" +"(defvar font-lock-auto-mode-list\n" +" (list 'c-mode 'c++-mode 'c++-c-mode 'emacs-lisp-mode 'whizbang-mode 'lisp-mode 'perl-mode 'scheme-mode)\n" +" \"List of modes to always start in font-lock-mode\")\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1625 +msgid "" +"This means that Emacs will always enable `font-lock-mode` (ie syntax " +"highlighting) when editing a [.filename]#.wiz# file." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1628 +msgid "" +"And that is all that is needed. If there is anything else you want done " +"automatically when you open up [.filename]#.wiz#, you can add a `whizbang-" +"mode hook` (see `my-scheme-mode-hook` for a simple example that adds `auto-" +"indent`)." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1630 +#, no-wrap +msgid "Further Reading" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1633 +msgid "" +"For information about setting up a development environment for contributing " +"fixes to FreeBSD itself, please see man:development[7]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1635 +msgid "" +"Brian Harvey and Matthew Wright _Simply Scheme_ MIT 1994. ISBN 0-262-08226-8" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1636 +msgid "Randall Schwartz _Learning Perl_ O'Reilly 1993 ISBN 1-56592-042-2" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1637 +msgid "" +"Patrick Henry Winston and Berthold Klaus Paul Horn _Lisp (3rd Edition)_ " +"Addison-Wesley 1989 ISBN 0-201-08319-1" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1638 +msgid "" +"Brian W. Kernighan and Rob Pike _The Unix Programming Environment_ Prentice-" +"Hall 1984 ISBN 0-13-937681-X" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1639 +msgid "" +"Brian W. Kernighan and Dennis M. Ritchie _The C Programming Language (2nd " +"Edition)_ Prentice-Hall 1988 ISBN 0-13-110362-8" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1640 +msgid "" +"Bjarne Stroustrup _The C++ Programming Language_ Addison-Wesley 1991 ISBN " +"0-201-53992-6" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1641 +msgid "" +"W. Richard Stevens _Advanced Programming in the Unix Environment_ Addison-" +"Wesley 1992 ISBN 0-201-56317-7" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/tools/_index.adoc:1641 +msgid "" +"W. Richard Stevens _Unix Network Programming_ Prentice-Hall 1990 ISBN " +"0-13-949876-1" +msgstr "" diff --git a/documentation/content/en/books/developers-handbook/x86/_index.adoc b/documentation/content/en/books/developers-handbook/x86/_index.adoc index 77b14e450d..b80e79bbec 100644 --- a/documentation/content/en/books/developers-handbook/x86/_index.adoc +++ b/documentation/content/en/books/developers-handbook/x86/_index.adoc @@ -7,7 +7,7 @@ description: x86 Assembly Language Programming tags: ["x86", "guide"] showBookMenu: true weight: 15 -path: "/books/developers-handbook/" +path: "/books/developers-handbook/x86/" --- [[x86]] @@ -79,14 +79,11 @@ Copyright (R) 2000-2001 G. Adam Stanislav. All rights reserved. The most important tool for assembly language programming is the assembler, the software that converts assembly language code into machine language. -Two very different assemblers are available for FreeBSD. -One is man:as[1], which uses the traditional UNIX(R) assembly language syntax. -It comes with the system. +Three very different assemblers are available for FreeBSD. +Both man:llvm-as[1] (included in package:devel/llvm[]) and man:as[1] (included in package:devel/binutils[]) use the traditional UNIX(R) assembly language syntax. -The other is /usr/ports/devel/nasm. -It uses the Intel syntax. +On the other hand, man:nasm[1] (installed through package:devel/nasm[]) uses the Intel syntax. Its main advantage is that it can assemble code for many operating systems. -It needs to be installed separately, but is completely free. This chapter uses nasm syntax because most assembly language programmers coming to FreeBSD from other operating systems will find it easier to understand. And, because, quite frankly, that is what I am used to. @@ -544,22 +541,22 @@ We are now ready for our first program, the mandatory Hello, World! [.programlisting] .... -1: %include 'system.inc' - 2: - 3: section .data - 4: hello db 'Hello, World!', 0Ah - 5: hbytes equ $-hello - 6: - 7: section .text - 8: global _start - 9: _start: -10: push dword hbytes -11: push dword hello -12: push dword stdout -13: sys.write -14: -15: push dword 0 -16: sys.exit + %include 'system.inc' + + section .data + hello db 'Hello, World!', 0Ah + hbytes equ $-hello + + section .text + global _start +_start: + push dword hbytes + push dword hello + push dword stdout + sys.write + + push dword 0 + sys.exit .... Here is what it does: Line 1 includes the defines, the macros, and the code from [.filename]#system.inc#. @@ -589,7 +586,7 @@ Which one it is, is for the system to figure out. [[x86-assemble-1]] === Assembling the Code -Type the code (except the line numbers) in an editor, and save it in a file named [.filename]#hello.asm#. +Type the code in an editor, and save it in a file named [.filename]#hello.asm#. You need nasm to assemble it. [[x86-get-nasm]] @@ -2898,7 +2895,7 @@ Syntax error: best Et cetera, et cetera, et cetera. -Secondly, I like the `#` character to denote the start of a comment which extends to the end of the line. +Secondly, I like the `+#+` character to denote the start of a comment which extends to the end of the line. This does not take too much effort to code, and lets me treat input files for my software as executable scripts. In our case, we also need to decide what units the input should come in: We choose _millimeters_ because that is how most photographers measure the focus length. @@ -3063,7 +3060,7 @@ Now, while we are taking these three steps, we also need to watch out for one of * If the counter grows above 18, we stop appending to the buffer. We continue reading the digits and sending them to the output. * If, or rather _when_, the next input character is not a digit, we are done inputting for now. + -Incidentally, we can simply discard the non-digit, unless it is a `#`, which we must return to the input stream. +Incidentally, we can simply discard the non-digit, unless it is a `+#+`, which we must return to the input stream. It starts a comment, so we must see it after we are done producing output and start looking for more input. That still leaves one possibility uncovered: If all the user enters is a zero (or several zeros), we will never find a non-zero to display. @@ -4107,7 +4104,7 @@ We have found that while for the focal length of 150, our pinhole diameter shoul [[x86-pinhole-scripting]] === Scripting -Because we have chosen the `#` character to denote the start of a comment, we can treat our pinhole software as a _scripting language_. +Because we have chosen the `+#+` character to denote the start of a comment, we can treat our pinhole software as a _scripting language_. You have probably seen shell _scripts_ that start with: diff --git a/documentation/content/en/books/developers-handbook/x86/_index.po b/documentation/content/en/books/developers-handbook/x86/_index.po new file mode 100644 index 0000000000..23cfaca453 --- /dev/null +++ b/documentation/content/en/books/developers-handbook/x86/_index.po @@ -0,0 +1,8103 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2024-01-17 20:34-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: Title = +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:14 +#, no-wrap +msgid "x86 Assembly Language Programming" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1 +#, no-wrap +msgid "Chapter 11. x86 Assembly Language Programming" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:52 +msgid "_This chapter was written by {stanislav}._" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:54 +#, no-wrap +msgid "Synopsis" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:58 +msgid "" +"Assembly language programming under UNIX(R) is highly undocumented. It is " +"generally assumed that no one would ever want to use it because various " +"UNIX(R) systems run on different microprocessors, so everything should be " +"written in C for portability." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:62 +msgid "" +"In reality, C portability is quite a myth. Even C programs need to be " +"modified when ported from one UNIX(R) to another, regardless of what " +"processor each runs on. Typically, such a program is full of conditional " +"statements depending on the system it is compiled for." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:64 +msgid "" +"Even if we believe that all of UNIX(R) software should be written in C, or " +"some other high-level language, we still need assembly language programmers: " +"Who else would write the section of C library that accesses the kernel?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:66 +msgid "" +"In this chapter I will attempt to show you how you can use assembly language " +"writing UNIX(R) programs, specifically under FreeBSD." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:71 +msgid "" +"This chapter does not explain the basics of assembly language. There are " +"enough resources about that (for a complete online course in assembly " +"language, see Randall Hyde's http://webster.cs.ucr.edu/[Art of Assembly " +"Language]; or if you prefer a printed book, take a look at Jeff Duntemann's " +"Assembly Language Step-by-Step (ISBN: 0471375233). However, once the " +"chapter is finished, any assembly language programmer will be able to write " +"programs for FreeBSD quickly and efficiently." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:73 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4310 +msgid "Copyright (R) 2000-2001 G. Adam Stanislav. All rights reserved." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:75 +#, no-wrap +msgid "The Tools" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:78 +#, no-wrap +msgid "The Assembler" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:81 +msgid "" +"The most important tool for assembly language programming is the assembler, " +"the software that converts assembly language code into machine language." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:84 +msgid "" +"Three very different assemblers are available for FreeBSD. Both man:llvm-" +"as[1] (included in package:devel/llvm[]) and man:as[1] (included in package:" +"devel/binutils[]) use the traditional UNIX(R) assembly language syntax." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:87 +msgid "" +"On the other hand, man:nasm[1] (installed through package:devel/nasm[]) uses " +"the Intel syntax. Its main advantage is that it can assemble code for many " +"operating systems." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:90 +msgid "" +"This chapter uses nasm syntax because most assembly language programmers " +"coming to FreeBSD from other operating systems will find it easier to " +"understand. And, because, quite frankly, that is what I am used to." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:92 +#, no-wrap +msgid "The Linker" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:95 +msgid "" +"The output of the assembler, like that of any compiler, needs to be linked " +"to form an executable file." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:98 +msgid "" +"The standard man:ld[1] linker comes with FreeBSD. It works with the code " +"assembled with either assembler." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:100 +#, no-wrap +msgid "System Calls" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:103 +#, no-wrap +msgid "Default Calling Convention" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:107 +msgid "" +"By default, the FreeBSD kernel uses the C calling convention. Further, " +"although the kernel is accessed using `int 80h`, it is assumed the program " +"will call a function that issues `int 80h`, rather than issuing `int 80h` " +"directly." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:110 +msgid "" +"This convention is very convenient, and quite superior to the Microsoft(R) " +"convention used by MS-DOS(R). Why? Because the UNIX(R) convention allows " +"any program written in any language to access the kernel." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:113 +msgid "" +"An assembly language program can do that as well. For example, we could " +"open a file:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:119 +#, no-wrap +msgid "" +"kernel:\n" +"\tint\t80h\t; Call kernel\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:128 +#, no-wrap +msgid "" +"open:\n" +"\tpush\tdword mode\n" +"\tpush\tdword flags\n" +"\tpush\tdword path\n" +"\tmov\teax, 5\n" +"\tcall\tkernel\n" +"\tadd\tesp, byte 12\n" +"\tret\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:132 +msgid "" +"This is a very clean and portable way of coding. If you need to port the " +"code to a UNIX(R) system which uses a different interrupt, or a different " +"way of passing parameters, all you need to change is the kernel procedure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:136 +msgid "" +"But assembly language programmers like to shave off cycles. The above " +"example requires a `call/ret` combination. We can eliminate it by " +"``push``ing an extra dword:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:147 +#, no-wrap +msgid "" +"open:\n" +"\tpush\tdword mode\n" +"\tpush\tdword flags\n" +"\tpush\tdword path\n" +"\tmov\teax, 5\n" +"\tpush\teax\t\t; Or any other dword\n" +"\tint\t80h\n" +"\tadd\tesp, byte 16\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:150 +msgid "" +"The `5` that we have placed in `EAX` identifies the kernel function, in this " +"case `open`." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:152 +#, no-wrap +msgid "Alternate Calling Convention" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:157 +msgid "" +"FreeBSD is an extremely flexible system. It offers other ways of calling " +"the kernel. For it to work, however, the system must have Linux emulation " +"installed." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:162 +msgid "" +"Linux is a UNIX(R) like system. However, its kernel uses the same system-" +"call convention of passing parameters in registers MS-DOS(R) does. As with " +"the UNIX(R) convention, the function number is placed in `EAX`. The " +"parameters, however, are not passed on the stack but in `EBX, ECX, EDX, ESI, " +"EDI, EBP`:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:171 +#, no-wrap +msgid "" +"open:\n" +"\tmov\teax, 5\n" +"\tmov\tebx, path\n" +"\tmov\tecx, flags\n" +"\tmov\tedx, mode\n" +"\tint\t80h\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:177 +msgid "" +"This convention has a great disadvantage over the UNIX(R) way, at least as " +"far as assembly language programming is concerned: Every time you make a " +"kernel call you must `push` the registers, then `pop` them later. This " +"makes your code bulkier and slower. Nevertheless, FreeBSD gives you a " +"choice." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:180 +msgid "" +"If you do choose the Linux convention, you must let the system know about " +"it. After your program is assembled and linked, you need to brand the " +"executable:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:184 +#, no-wrap +msgid "% brandelf -t Linux filename\n" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:187 +#, no-wrap +msgid "Which Convention Should You Use?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:192 +msgid "" +"If you are coding specifically for FreeBSD, you should always use the " +"UNIX(R) convention: It is faster, you can store global variables in " +"registers, you do not have to brand the executable, and you do not impose " +"the installation of the Linux emulation package on the target system." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:195 +msgid "" +"If you want to create portable code that can also run on Linux, you will " +"probably still want to give the FreeBSD users as efficient a code as " +"possible. I will show you how you can accomplish that after I have " +"explained the basics." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:197 +#, no-wrap +msgid "Call Numbers" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:201 +msgid "" +"To tell the kernel which system service you are calling, place its number in " +"`EAX`. Of course, you need to know what the number is." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:203 +#, no-wrap +msgid "The [.filename]#syscalls# File" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:207 +msgid "" +"The numbers are listed in [.filename]#syscalls#. `locate syscalls` finds " +"this file in several different formats, all produced automatically from [." +"filename]#syscalls.master#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:210 +msgid "" +"You can find the master file for the default UNIX(R) calling convention in [." +"filename]#/usr/src/sys/kern/syscalls.master#. If you need to use the other " +"convention implemented in the Linux emulation mode, read [.filename]#/usr/" +"src/sys/i386/linux/syscalls.master#." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:214 +msgid "" +"Not only do FreeBSD and Linux use different calling conventions, they " +"sometimes use different numbers for the same functions." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:217 +msgid "[.filename]#syscalls.master# describes how the call is to be made:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:228 +#, no-wrap +msgid "" +"0\tSTD\tNOHIDE\t{ int nosys(void); } syscall nosys_args int\n" +"1\tSTD\tNOHIDE\t{ void exit(int rval); } exit rexit_args void\n" +"2\tSTD\tPOSIX\t{ int fork(void); }\n" +"3\tSTD\tPOSIX\t{ ssize_t read(int fd, void *buf, size_t nbyte); }\n" +"4\tSTD\tPOSIX\t{ ssize_t write(int fd, const void *buf, size_t nbyte); }\n" +"5\tSTD\tPOSIX\t{ int open(char *path, int flags, int mode); }\n" +"6\tSTD\tPOSIX\t{ int close(int fd); }\n" +"etc...\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:231 +msgid "It is the leftmost column that tells us the number to place in `EAX`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:234 +msgid "" +"The rightmost column tells us what parameters to `push`. They are " +"``push``ed _from right to left_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:236 +msgid "" +"For example, to `open` a file, we need to `push` the `mode` first, then " +"`flags`, then the address at which the `path` is stored." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:238 +#, no-wrap +msgid "Return Values" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:242 +msgid "" +"A system call would not be useful most of the time if it did not return some " +"kind of a value: The file descriptor of an open file, the number of bytes " +"read to a buffer, the system time, etc." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:245 +msgid "" +"Additionally, the system needs to inform us if an error occurs: A file does " +"not exist, system resources are exhausted, we passed an invalid parameter, " +"etc." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:247 +#, no-wrap +msgid "Man Pages" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:251 +msgid "" +"The traditional place to look for information about various system calls " +"under UNIX(R) systems are the manual pages. FreeBSD describes its system " +"calls in section 2, sometimes in section 3." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:253 +msgid "For example, man:open[2] says:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:257 +msgid "" +"If successful, `open()` returns a non-negative integer, termed a file " +"descriptor. It returns `-1` on failure, and sets `errno` to indicate the " +"error." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:259 +msgid "" +"The assembly language programmer new to UNIX(R) and FreeBSD will immediately " +"ask the puzzling question: Where is `errno` and how do I get to it?" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:264 +msgid "" +"The information presented in the manual pages applies to C programs. The " +"assembly language programmer needs additional information." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:267 +#, no-wrap +msgid "Where Are the Return Values?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:272 +msgid "" +"Unfortunately, it depends... For most system calls it is in `EAX`, but not " +"for all. A good rule of thumb, when working with a system call for the " +"first time, is to look for the return value in `EAX`. If it is not there, " +"you need further research." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:278 +msgid "" +"I am aware of one system call that returns the value in `EDX`: `SYS_fork`. " +"All others I have worked with use `EAX`. But I have not worked with them " +"all yet." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:283 +msgid "" +"If you cannot find the answer here or anywhere else, study libc source code " +"and see how it interfaces with the kernel." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:286 +#, no-wrap +msgid "Where Is `errno`?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:289 +msgid "Actually, nowhere..." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:292 +msgid "" +"`errno` is part of the C language, not the UNIX(R) kernel. When accessing " +"kernel services directly, the error code is returned in `EAX`, the same " +"register the proper return value generally ends up in." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:296 +msgid "" +"This makes perfect sense. If there is no error, there is no error code. If " +"there is an error, there is no return value. One register can contain " +"either." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:298 +#, no-wrap +msgid "Determining an Error Occurred" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:301 +msgid "" +"When using the standard FreeBSD calling convention, the `carry flag` is " +"cleared upon success, set upon failure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:304 +msgid "" +"When using the Linux emulation mode, the signed value in `EAX` is non-" +"negative upon success, and contains the return value. In case of an error, " +"the value is negative, i.e., `-errno`." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:306 +#, no-wrap +msgid "Creating Portable Code" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:311 +msgid "" +"Portability is generally not one of the strengths of assembly language. " +"Yet, writing assembly language programs for different platforms is possible, " +"especially with nasm. I have written assembly language libraries that can " +"be assembled for such different operating systems as Windows(R) and FreeBSD." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:313 +msgid "" +"It is all the more possible when you want your code to run on two platforms " +"which, while different, are based on similar architectures." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:317 +msgid "" +"For example, FreeBSD is UNIX(R), Linux is UNIX(R) like. I only mentioned " +"three differences between them (from an assembly language programmer's " +"perspective): The calling convention, the function numbers, and the way of " +"returning values." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:319 +#, no-wrap +msgid "Dealing with Function Numbers" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:324 +msgid "" +"In many cases the function numbers are the same. However, even when they " +"are not, the problem is easy to deal with: Instead of using numbers in your " +"code, use constants which you have declared differently depending on the " +"target architecture:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:332 +#, no-wrap +msgid "" +"%ifdef\tLINUX\n" +"%define\tSYS_execve\t11\n" +"%else\n" +"%define\tSYS_execve\t59\n" +"%endif\n" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:335 +#, no-wrap +msgid "Dealing with Conventions" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:338 +msgid "" +"Both, the calling convention, and the return value (the `errno` problem) can " +"be resolved with macros:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:342 +#, no-wrap +msgid "%ifdef\tLINUX\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:346 +#, no-wrap +msgid "" +"%macro\tsystem\t0\n" +"\tcall\tkernel\n" +"%endmacro\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:355 +#, no-wrap +msgid "" +"align 4\n" +"kernel:\n" +"\tpush\tebx\n" +"\tpush\tecx\n" +"\tpush\tedx\n" +"\tpush\tesi\n" +"\tpush\tedi\n" +"\tpush\tebp\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:362 +#, no-wrap +msgid "" +"\tmov\tebx, [esp+32]\n" +"\tmov\tecx, [esp+36]\n" +"\tmov\tedx, [esp+40]\n" +"\tmov\tesi, [esp+44]\n" +"\tmov\tebp, [esp+48]\n" +"\tint\t80h\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:369 +#, no-wrap +msgid "" +"\tpop\tebp\n" +"\tpop\tedi\n" +"\tpop\tesi\n" +"\tpop\tedx\n" +"\tpop\tecx\n" +"\tpop\tebx\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:374 +#, no-wrap +msgid "" +"\tor\teax, eax\n" +"\tjs\t.errno\n" +"\tclc\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:379 +#, no-wrap +msgid "" +".errno:\n" +"\tneg\teax\n" +"\tstc\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:381 +#, no-wrap +msgid "%else\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:385 +#, no-wrap +msgid "" +"%macro\tsystem\t0\n" +"\tint\t80h\n" +"%endmacro\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:387 +#, no-wrap +msgid "%endif\n" +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:390 +#, no-wrap +msgid "Dealing with Other Portability Issues" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:394 +msgid "" +"The above solutions can handle most cases of writing code portable between " +"FreeBSD and Linux. Nevertheless, with some kernel services the differences " +"are deeper." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:397 +msgid "" +"In that case, you need to write two different handlers for those particular " +"system calls, and use conditional assembly. Luckily, most of your code does " +"something other than calling the kernel, so usually you will only need a few " +"such conditional sections in your code." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:399 +#, no-wrap +msgid "Using a Library" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:403 +msgid "" +"You can avoid portability issues in your main code altogether by writing a " +"library of system calls. Create a separate library for FreeBSD, a different " +"one for Linux, and yet other libraries for more operating systems." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:408 +msgid "" +"In your library, write a separate function (or procedure, if you prefer the " +"traditional assembly language terminology) for each system call. Use the C " +"calling convention of passing parameters. But still use `EAX` to pass the " +"call number in. In that case, your FreeBSD library can be very simple, as " +"many seemingly different functions can be just labels to the same code:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:416 +#, no-wrap +msgid "" +"sys.open:\n" +"sys.close:\n" +"[etc...]\n" +"\tint\t80h\n" +"\tret\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:420 +msgid "" +"Your Linux library will require more different functions. But even here you " +"can group system calls using the same number of parameters:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:431 +#, no-wrap +msgid "" +"sys.exit:\n" +"sys.close:\n" +"[etc... one-parameter functions]\n" +"\tpush\tebx\n" +"\tmov\tebx, [esp+12]\n" +"\tint\t80h\n" +"\tpop\tebx\n" +"\tjmp\tsys.return\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:433 +#, no-wrap +msgid "...\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:439 +#, no-wrap +msgid "" +"sys.return:\n" +"\tor\teax, eax\n" +"\tjs\tsys.err\n" +"\tclc\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:444 +#, no-wrap +msgid "" +"sys.err:\n" +"\tneg\teax\n" +"\tstc\n" +"\tret\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:451 +msgid "" +"The library approach may seem inconvenient at first because it requires you " +"to produce a separate file your code depends on. But it has many " +"advantages: For one, you only need to write it once and can use it for all " +"your programs. You can even let other assembly language programmers use it, " +"or perhaps use one written by someone else. But perhaps the greatest " +"advantage of the library is that your code can be ported to other systems, " +"even by other programmers, by simply writing a new library without any " +"changes to your code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:453 +msgid "" +"If you do not like the idea of having a library, you can at least place all " +"your system calls in a separate assembly language file and link it with your " +"main program. Here, again, all porters have to do is create a new object " +"file to link with your main program." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:455 +#, no-wrap +msgid "Using an Include File" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:458 +msgid "" +"If you are releasing your software as (or with) source code, you can use " +"macros and place them in a separate file, which you include in your code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:461 +msgid "" +"Porters of your software will simply write a new include file. No library " +"or external object file is necessary, yet your code is portable without any " +"need to edit the code." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:466 +msgid "" +"This is the approach we will use throughout this chapter. We will name our " +"include file [.filename]#system.inc#, and add to it whenever we deal with a " +"new system call." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:469 +msgid "" +"We can start our [.filename]#system.inc# by declaring the standard file " +"descriptors:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:475 +#, no-wrap +msgid "" +"%define\tstdin\t0\n" +"%define\tstdout\t1\n" +"%define\tstderr\t2\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:478 +msgid "Next, we create a symbolic name for each system call:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:487 +#, no-wrap +msgid "" +"%define\tSYS_nosys\t0\n" +"%define\tSYS_exit\t1\n" +"%define\tSYS_fork\t2\n" +"%define\tSYS_read\t3\n" +"%define\tSYS_write\t4\n" +"; [etc...]\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:490 +msgid "" +"We add a short, non-global procedure with a long name, so we do not " +"accidentally reuse the name in our code:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:498 +#, no-wrap +msgid "" +"section\t.text\n" +"align 4\n" +"access.the.bsd.kernel:\n" +"\tint\t80h\n" +"\tret\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:501 +msgid "We create a macro which takes one argument, the syscall number:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:508 +#, no-wrap +msgid "" +"%macro\tsystem\t1\n" +"\tmov\teax, %1\n" +"\tcall\taccess.the.bsd.kernel\n" +"%endmacro\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:512 +msgid "" +"Finally, we create macros for each syscall. These macros take no arguments." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:518 +#, no-wrap +msgid "" +"%macro\tsys.exit\t0\n" +"\tsystem\tSYS_exit\n" +"%endmacro\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:522 +#, no-wrap +msgid "" +"%macro\tsys.fork\t0\n" +"\tsystem\tSYS_fork\n" +"%endmacro\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:526 +#, no-wrap +msgid "" +"%macro\tsys.read\t0\n" +"\tsystem\tSYS_read\n" +"%endmacro\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:530 +#, no-wrap +msgid "" +"%macro\tsys.write\t0\n" +"\tsystem\tSYS_write\n" +"%endmacro\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:532 +#, no-wrap +msgid "; [etc...]\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:536 +msgid "" +"Go ahead, enter it into your editor and save it as [.filename]#system.inc#. " +"We will add more to it as we discuss more syscalls." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:538 +#, no-wrap +msgid "Our First Program" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:541 +msgid "We are now ready for our first program, the mandatory Hello, World!" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:560 +#, no-wrap +msgid "" +"1:\t%include\t'system.inc'\n" +" 2:\n" +" 3:\tsection\t.data\n" +" 4:\thello\tdb\t'Hello, World!', 0Ah\n" +" 5:\thbytes\tequ\t$-hello\n" +" 6:\n" +" 7:\tsection\t.text\n" +" 8:\tglobal\t_start\n" +" 9:\t_start:\n" +"10:\tpush\tdword hbytes\n" +"11:\tpush\tdword hello\n" +"12:\tpush\tdword stdout\n" +"13:\tsys.write\n" +"14:\n" +"15:\tpush\tdword 0\n" +"16:\tsys.exit\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:563 +msgid "" +"Here is what it does: Line 1 includes the defines, the macros, and the code " +"from [.filename]#system.inc#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:567 +msgid "" +"Lines 3-5 are the data: Line 3 starts the data section/segment. Line 4 " +"contains the string \"Hello, World!\" followed by a new line (`0Ah`). Line " +"5 creates a constant that contains the length of the string from line 4 in " +"bytes." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:571 +msgid "" +"Lines 7-16 contain the code. Note that FreeBSD uses the _elf_ file format " +"for its executables, which requires every program to start at the point " +"labeled `_start` (or, more precisely, the linker expects that). This label " +"has to be global." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:573 +msgid "" +"Lines 10-13 ask the system to write `hbytes` bytes of the `hello` string to " +"`stdout`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:576 +msgid "" +"Lines 15-16 ask the system to end the program with the return value of `0`. " +"The `SYS_exit` syscall never returns, so the code ends there." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:584 +msgid "" +"If you have come to UNIX(R) from MS-DOS(R) assembly language background, you " +"may be used to writing directly to the video hardware. You will never have " +"to worry about this in FreeBSD, or any other flavor of UNIX(R). As far as " +"you are concerned, you are writing to a file known as [.filename]#stdout#. " +"This can be the video screen, or a telnet terminal, or an actual file, or " +"even the input of another program. Which one it is, is for the system to " +"figure out." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:587 +#, no-wrap +msgid "Assembling the Code" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:591 +msgid "" +"Type the code (except the line numbers) in an editor, and save it in a file " +"named [.filename]#hello.asm#. You need nasm to assemble it." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:593 +#, no-wrap +msgid "Installing nasm" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:596 +msgid "If you do not have nasm, type:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:605 +#, no-wrap +msgid "" +"% su\n" +"Password:your root password\n" +"# cd /usr/ports/devel/nasm\n" +"# make install\n" +"# exit\n" +"%\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:608 +msgid "" +"You may type `make install clean` instead of just `make install` if you do " +"not want to keep nasm source code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:610 +msgid "" +"Either way, FreeBSD will automatically download nasm from the Internet, " +"compile it, and install it on your system." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:615 +msgid "" +"If your system is not FreeBSD, you need to get nasm from its https://" +"sourceforge.net/projects/nasm[home page]. You can still use it to assemble " +"FreeBSD code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:618 +msgid "Now you can assemble, link, and run the code:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:626 +#, no-wrap +msgid "" +"% nasm -f elf hello.asm\n" +"% ld -s -o hello hello.o\n" +"% ./hello\n" +"Hello, World!\n" +"%\n" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:629 +#, no-wrap +msgid "Writing UNIX(R) Filters" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:632 +msgid "" +"A common type of UNIX(R) application is a filter-a program that reads data " +"from the [.filename]#stdin#, processes it somehow, then writes the result to " +"[.filename]#stdout#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:635 +msgid "" +"In this chapter, we shall develop a simple filter, and learn how to read " +"from [.filename]#stdin# and write to [.filename]#stdout#. This filter will " +"convert each byte of its input into a hexadecimal number followed by a blank " +"space." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:639 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:733 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:823 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:951 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1218 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2336 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3334 +#, no-wrap +msgid "%include\t'system.inc'\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:643 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:737 +#, no-wrap +msgid "" +"section\t.data\n" +"hex\tdb\t'0123456789ABCDEF'\n" +"buffer\tdb\t0, 0, ' '\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:655 +#, no-wrap +msgid "" +"section\t.text\n" +"global\t_start\n" +"_start:\n" +"\t; read a byte from stdin\n" +"\tpush\tdword 1\n" +"\tpush\tdword buffer\n" +"\tpush\tdword stdin\n" +"\tsys.read\n" +"\tadd\tesp, byte 12\n" +"\tor\teax, eax\n" +"\tje\t.done\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:665 +#, no-wrap +msgid "" +"\t; convert it to hex\n" +"\tmovzx\teax, byte [buffer]\n" +"\tmov\tedx, eax\n" +"\tshr\tdl, 4\n" +"\tmov\tdl, [hex+edx]\n" +"\tmov\t[buffer], dl\n" +"\tand\tal, 0Fh\n" +"\tmov\tal, [hex+eax]\n" +"\tmov\t[buffer+1], al\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:673 +#, no-wrap +msgid "" +"\t; print it\n" +"\tpush\tdword 3\n" +"\tpush\tdword buffer\n" +"\tpush\tdword stdout\n" +"\tsys.write\n" +"\tadd\tesp, byte 12\n" +"\tjmp\tshort _start\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:677 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:780 +#, no-wrap +msgid "" +".done:\n" +"\tpush\tdword 0\n" +"\tsys.exit\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:685 +msgid "" +"In the data section we create an array called `hex`. It contains the 16 " +"hexadecimal digits in ascending order. The array is followed by a buffer " +"which we will use for both input and output. The first two bytes of the " +"buffer are initially set to `0`. This is where we will write the two " +"hexadecimal digits (the first byte also is where we will read the input). " +"The third byte is a space." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:687 +msgid "" +"The code section consists of four parts: Reading the byte, converting it to " +"a hexadecimal number, writing the result, and eventually exiting the program." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:693 +msgid "" +"To read the byte, we ask the system to read one byte from [." +"filename]#stdin#, and store it in the first byte of the `buffer`. The " +"system returns the number of bytes read in `EAX`. This will be `1` while " +"data is coming, or `0`, when no more input data is available. Therefore, we " +"check the value of `EAX`. If it is `0`, we jump to `.done`, otherwise we " +"continue." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:697 +msgid "" +"For simplicity sake, we are ignoring the possibility of an error condition " +"at this time." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:702 +msgid "" +"The hexadecimal conversion reads the byte from the `buffer` into `EAX`, or " +"actually just `AL`, while clearing the remaining bits of `EAX` to zeros. We " +"also copy the byte to `EDX` because we need to convert the upper four bits " +"(nibble) separately from the lower four bits. We store the result in the " +"first two bytes of the buffer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:705 +msgid "" +"Next, we ask the system to write the three bytes of the buffer, i.e., the " +"two hexadecimal digits and the blank space, to [.filename]#stdout#. We then " +"jump back to the beginning of the program and process the next byte." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:707 +msgid "" +"Once there is no more input left, we ask the system to exit our program, " +"returning a zero, which is the traditional value meaning the program was " +"successful." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:709 +msgid "" +"Go ahead, and save the code in a file named [.filename]#hex.asm#, then type " +"the following (the `^D` means press the control key and type `D` while " +"holding the control key down):" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:718 +#, no-wrap +msgid "" +"% nasm -f elf hex.asm\n" +"% ld -s -o hex hex.o\n" +"% ./hex\n" +"Hello, World!\n" +"48 65 6C 6C 6F 2C 20 57 6F 72 6C 64 21 0A Here I come!\n" +"48 65 72 65 20 49 20 63 6F 6D 65 21 0A ^D %\n" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:724 +msgid "" +"If you are migrating to UNIX(R) from MS-DOS(R), you may be wondering why " +"each line ends with `0A` instead of `0D 0A`. This is because UNIX(R) does " +"not use the cr/lf convention, but a \"new line\" convention, which is `0A` " +"in hexadecimal." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:729 +msgid "" +"Can we improve this? Well, for one, it is a bit confusing because once we " +"have converted a line of text, our input no longer starts at the beginning " +"of the line. We can modify it to print a new line instead of a space after " +"each `0A`:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:742 +#, no-wrap +msgid "" +"section\t.text\n" +"global\t_start\n" +"_start:\n" +"\tmov\tcl, ' '\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:752 +#, no-wrap +msgid "" +".loop:\n" +"\t; read a byte from stdin\n" +"\tpush\tdword 1\n" +"\tpush\tdword buffer\n" +"\tpush\tdword stdin\n" +"\tsys.read\n" +"\tadd\tesp, byte 12\n" +"\tor\teax, eax\n" +"\tje\t.done\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:759 +#, no-wrap +msgid "" +"\t; convert it to hex\n" +"\tmovzx\teax, byte [buffer]\n" +"\tmov\t[buffer+2], cl\n" +"\tcmp\tal, 0Ah\n" +"\tjne\t.hex\n" +"\tmov\t[buffer+2], al\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:768 +#, no-wrap +msgid "" +".hex:\n" +"\tmov\tedx, eax\n" +"\tshr\tdl, 4\n" +"\tmov\tdl, [hex+edx]\n" +"\tmov\t[buffer], dl\n" +"\tand\tal, 0Fh\n" +"\tmov\tal, [hex+eax]\n" +"\tmov\t[buffer+1], al\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:776 +#, no-wrap +msgid "" +"\t; print it\n" +"\tpush\tdword 3\n" +"\tpush\tdword buffer\n" +"\tpush\tdword stdout\n" +"\tsys.write\n" +"\tadd\tesp, byte 12\n" +"\tjmp\tshort .loop\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:784 +msgid "" +"We have stored the space in the `CL` register. We can do this safely " +"because, unlike Microsoft(R) Windows(R), UNIX(R) system calls do not modify " +"the value of any register they do not use to return a value in." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:788 +msgid "" +"That means we only need to set `CL` once. We have, therefore, added a new " +"label `.loop` and jump to it for the next byte instead of jumping at " +"`_start`. We have also added the `.hex` label so we can either have a blank " +"space or a new line as the third byte of the `buffer`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:790 +msgid "" +"Once you have changed [.filename]#hex.asm# to reflect these changes, type:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:801 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1060 +#, no-wrap +msgid "" +"% nasm -f elf hex.asm\n" +"% ld -s -o hex hex.o\n" +"% ./hex\n" +"Hello, World!\n" +"48 65 6C 6C 6F 2C 20 57 6F 72 6C 64 21 0A\n" +"Here I come!\n" +"48 65 72 65 20 49 20 63 6F 6D 65 21 0A\n" +"^D %\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:805 +msgid "" +"That looks better. But this code is quite inefficient! We are making a " +"system call for every single byte twice (once to read it, another time to " +"write the output)." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:807 +#, no-wrap +msgid "Buffered Input and Output" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:812 +msgid "" +"We can improve the efficiency of our code by buffering our input and " +"output. We create an input buffer and read a whole sequence of bytes at one " +"time. Then we fetch them one by one from the buffer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:815 +msgid "" +"We also create an output buffer. We store our output in it until it is " +"full. At that time we ask the kernel to write the contents of the buffer to " +"[.filename]#stdout#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:819 +msgid "" +"The program ends when there is no more input. But we still need to ask the " +"kernel to write the contents of our output buffer to [.filename]#stdout# one " +"last time, otherwise some of our output would make it to the output buffer, " +"but never be sent out. Do not forget that, or you will be wondering why " +"some of your output is missing." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:825 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:953 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1220 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2338 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3336 +#, no-wrap +msgid "%define\tBUFSIZE\t2048\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:828 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:956 +#, no-wrap +msgid "" +"section\t.data\n" +"hex\tdb\t'0123456789ABCDEF'\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:832 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:960 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1229 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2352 +#, no-wrap +msgid "" +"section .bss\n" +"ibuffer\tresb\tBUFSIZE\n" +"obuffer\tresb\tBUFSIZE\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:840 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:968 +#, no-wrap +msgid "" +"section\t.text\n" +"global\t_start\n" +"_start:\n" +"\tsub\teax, eax\n" +"\tsub\tebx, ebx\n" +"\tsub\tecx, ecx\n" +"\tmov\tedi, obuffer\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:844 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:972 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2500 +#, no-wrap +msgid "" +".loop:\n" +"\t; read a byte from stdin\n" +"\tcall\tgetchar\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:850 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:978 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1282 +#, no-wrap +msgid "" +"\t; convert it to hex\n" +"\tmov\tdl, al\n" +"\tshr\tal, 4\n" +"\tmov\tal, [hex+eax]\n" +"\tcall\tputchar\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:855 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:983 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1287 +#, no-wrap +msgid "" +"\tmov\tal, dl\n" +"\tand\tal, 0Fh\n" +"\tmov\tal, [hex+eax]\n" +"\tcall\tputchar\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:860 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:988 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1292 +#, no-wrap +msgid "" +"\tmov\tal, ' '\n" +"\tcmp\tdl, 0Ah\n" +"\tjne\t.put\n" +"\tmov\tal, dl\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:864 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2511 +#, no-wrap +msgid "" +".put:\n" +"\tcall\tputchar\n" +"\tjmp\tshort .loop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:869 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1000 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1304 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2533 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3847 +#, no-wrap +msgid "" +"align 4\n" +"getchar:\n" +"\tor\tebx, ebx\n" +"\tjne\t.fetch\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:871 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1002 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1306 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2535 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3849 +#, no-wrap +msgid "\tcall\tread\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:876 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1007 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1311 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2540 +#, no-wrap +msgid "" +".fetch:\n" +"\tlodsb\n" +"\tdec\tebx\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:889 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1020 +#, no-wrap +msgid "" +"read:\n" +"\tpush\tdword BUFSIZE\n" +"\tmov\tesi, ibuffer\n" +"\tpush\tesi\n" +"\tpush\tdword stdin\n" +"\tsys.read\n" +"\tadd\tesp, byte 12\n" +"\tmov\tebx, eax\n" +"\tor\teax, eax\n" +"\tje\t.done\n" +"\tsub\teax, eax\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:895 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1026 +#, no-wrap +msgid "" +"align 4\n" +".done:\n" +"\tcall\twrite\t\t; flush output buffer\n" +"\tpush\tdword 0\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:903 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1034 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1347 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2580 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3886 +#, no-wrap +msgid "" +"align 4\n" +"putchar:\n" +"\tstosb\n" +"\tinc\tecx\n" +"\tcmp\tecx, BUFSIZE\n" +"\tje\twrite\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:915 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1046 +#, no-wrap +msgid "" +"align 4\n" +"write:\n" +"\tsub\tedi, ecx\t; start of buffer\n" +"\tpush\tecx\n" +"\tpush\tedi\n" +"\tpush\tdword stdout\n" +"\tsys.write\n" +"\tadd\tesp, byte 12\n" +"\tsub\teax, eax\n" +"\tsub\tecx, ecx\t; buffer is empty now\n" +"\tret\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:921 +msgid "" +"We now have a third section in the source code, named `.bss`. This section " +"is not included in our executable file, and, therefore, cannot be " +"initialized. We use `resb` instead of `db`. It simply reserves the " +"requested size of uninitialized memory for our use." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:925 +msgid "" +"We take advantage of the fact that the system does not modify the registers: " +"We use registers for what, otherwise, would have to be global variables " +"stored in the `.data` section. This is also why the UNIX(R) convention of " +"passing parameters to system calls on the stack is superior to the Microsoft " +"convention of passing them in the registers: We can keep the registers for " +"our own use." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:929 +msgid "" +"We use `EDI` and `ESI` as pointers to the next byte to be read from or " +"written to. We use `EBX` and `ECX` to keep count of the number of bytes in " +"the two buffers, so we know when to dump the output to, or read more input " +"from, the system." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:931 +msgid "Let us see how it works now:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:942 +#, no-wrap +msgid "" +"% nasm -f elf hex.asm\n" +"% ld -s -o hex hex.o\n" +"% ./hex\n" +"Hello, World!\n" +"Here I come!\n" +"48 65 6C 6C 6F 2C 20 57 6F 72 6C 64 21 0A\n" +"48 65 72 65 20 49 20 63 6F 6D 65 21 0A\n" +"^D %\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:947 +msgid "" +"Not what you expected? The program did not print the output until we pressed " +"`^D`. That is easy to fix by inserting three lines of code to write the " +"output every time we have converted a new line to `0A`. I have marked the " +"three lines with > (do not copy the > in your [.filename]#hex.asm#)." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:995 +#, no-wrap +msgid "" +".put:\n" +"\tcall\tputchar\n" +">\tcmp\tal, 0Ah\n" +">\tjne\t.loop\n" +">\tcall\twrite\n" +"\tjmp\tshort .loop\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1049 +msgid "Now, let us see how it works:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1063 +msgid "Not bad for a 644-byte executable, is it!" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1068 +msgid "" +"This approach to buffered input/output still contains a hidden danger. I " +"will discuss-and fix-it later, when I talk about the <<x86-buffered-dark-" +"side,dark side of buffering>>." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1071 +#, no-wrap +msgid "How to Unread a Character" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1077 +msgid "" +"This may be a somewhat advanced topic, mostly of interest to programmers " +"familiar with the theory of compilers. If you wish, you may <<x86-command-" +"line,skip to the next section>>, and perhaps read this later." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1083 +msgid "" +"While our sample program does not require it, more sophisticated filters " +"often need to look ahead. In other words, they may need to see what the " +"next character is (or even several characters). If the next character is of " +"a certain value, it is part of the token currently being processed. " +"Otherwise, it is not." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1087 +msgid "" +"For example, you may be parsing the input stream for a textual string (e.g., " +"when implementing a language compiler): If a character is followed by " +"another character, or perhaps a digit, it is part of the token you are " +"processing. If it is followed by white space, or some other value, then it " +"is not part of the current token." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1089 +msgid "" +"This presents an interesting problem: How to return the next character back " +"to the input stream, so it can be read again later?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1093 +msgid "" +"One possible solution is to store it in a character variable, then set a " +"flag. We can modify `getchar` to check the flag, and if it is set, fetch " +"the byte from that variable instead of the input buffer, and reset the " +"flag. But, of course, that slows us down." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1098 +msgid "" +"The C language has an `ungetc()` function, just for that purpose. Is there " +"a quick way to implement it in our code? I would like you to scroll back up " +"and take a look at the `getchar` procedure and see if you can find a nice " +"and fast solution before reading the next paragraph. Then come back here " +"and see my own solution." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1100 +msgid "" +"The key to returning a character back to the stream is in how we are getting " +"the characters to start with:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1103 +msgid "" +"First we check if the buffer is empty by testing the value of `EBX`. If it " +"is zero, we call the `read` procedure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1106 +msgid "" +"If we do have a character available, we use `lodsb`, then decrease the value " +"of `EBX`. The `lodsb` instruction is effectively identical to:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1111 +#, no-wrap +msgid "" +"mov\tal, [esi]\n" +"\tinc\tesi\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1116 +msgid "" +"The byte we have fetched remains in the buffer until the next time `read` is " +"called. We do not know when that happens, but we do know it will not happen " +"until the next call to `getchar`. Hence, to \"return\" the last-read byte " +"back to the stream, all we have to do is decrease the value of `ESI` and " +"increase the value of `EBX`:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1123 +#, no-wrap +msgid "" +"ungetc:\n" +"\tdec\tesi\n" +"\tinc\tebx\n" +"\tret\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1127 +msgid "" +"But, be careful! We are perfectly safe doing this if our look-ahead is at " +"most one character at a time. If we are examining more than one upcoming " +"character and call `ungetc` several times in a row, it will work most of the " +"time, but not all the time (and will be tough to debug). Why?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1130 +msgid "" +"Because as long as `getchar` does not have to call `read`, all of the pre-" +"read bytes are still in the buffer, and our `ungetc` works without a " +"glitch. But the moment `getchar` calls `read`, the contents of the buffer " +"change." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1132 +msgid "" +"We can always rely on `ungetc` working properly on the last character we " +"have read with `getchar`, but not on anything we have read before that." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1134 +msgid "" +"If your program reads more than one byte ahead, you have at least two " +"choices:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1137 +msgid "" +"If possible, modify the program so it only reads one byte ahead. This is " +"the simplest solution." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1141 +msgid "" +"If that option is not available, first of all determine the maximum number " +"of characters your program needs to return to the input stream at one time. " +"Increase that number slightly, just to be sure, preferably to a multiple of " +"16-so it aligns nicely. Then modify the `.bss` section of your code, and " +"create a small \"spare\" buffer right before your input buffer, something " +"like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1148 +#, no-wrap +msgid "" +"section\t.bss\n" +"\tresb\t16\t; or whatever the value you came up with\n" +"ibuffer\tresb\tBUFSIZE\n" +"obuffer\tresb\tBUFSIZE\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1151 +msgid "" +"You also need to modify your `ungetc` to pass the value of the byte to unget " +"in `AL`:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1159 +#, no-wrap +msgid "" +"ungetc:\n" +"\tdec\tesi\n" +"\tinc\tebx\n" +"\tmov\t[esi], al\n" +"\tret\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1162 +msgid "" +"With this modification, you can call `ungetc` up to 17 times in a row safely " +"(the first call will still be within the buffer, the remaining 16 may be " +"either within the buffer or within the \"spare\")." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1164 +#, no-wrap +msgid "Command Line Arguments" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1168 +msgid "" +"Our hex program will be more useful if it can read the names of an input and " +"output file from its command line, i.e., if it can process the command line " +"arguments. But... Where are they?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1172 +msgid "" +"Before a UNIX(R) system starts a program, it ``push``es some data on the " +"stack, then jumps at the `_start` label of the program. Yes, I said jumps, " +"not calls. That means the data can be accessed by reading `[esp+offset]`, " +"or by simply ``pop``ping it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1175 +msgid "" +"The value at the top of the stack contains the number of command line " +"arguments. It is traditionally called `argc`, for \"argument count.\"" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1180 +msgid "" +"Command line arguments follow next, all `argc` of them. These are typically " +"referred to as `argv`, for \"argument value(s).\" That is, we get `argv[0]`, " +"`argv[1]`, `...`, `argv[argc-1]`. These are not the actual arguments, but " +"pointers to arguments, i.e., memory addresses of the actual arguments. The " +"arguments themselves are NUL-terminated character strings." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1182 +msgid "" +"The `argv` list is followed by a NULL pointer, which is simply a `0`. There " +"is more, but this is enough for our purposes right now." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1187 +msgid "" +"If you have come from the MS-DOS(R) programming environment, the main " +"difference is that each argument is in a separate string. The second " +"difference is that there is no practical limit on how many arguments there " +"can be." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1191 +msgid "" +"Armed with this knowledge, we are almost ready for the next version of [." +"filename]#hex.asm#. First, however, we need to add a few lines to [." +"filename]#system.inc#:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1193 +msgid "" +"First, we need to add two new entries to our list of system call numbers:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1198 +#, no-wrap +msgid "" +"%define\tSYS_open\t5\n" +"%define\tSYS_close\t6\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1201 +msgid "Then we add two new macros at the end of the file:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1207 +#, no-wrap +msgid "" +"%macro\tsys.open\t0\n" +"\tsystem\tSYS_open\n" +"%endmacro\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1211 +#, no-wrap +msgid "" +"%macro\tsys.close\t0\n" +"\tsystem\tSYS_close\n" +"%endmacro\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1214 +msgid "Here, then, is our modified source code:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1225 +#, no-wrap +msgid "" +"section\t.data\n" +"fd.in\tdd\tstdin\n" +"fd.out\tdd\tstdout\n" +"hex\tdb\t'0123456789ABCDEF'\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1235 +#, no-wrap +msgid "" +"section\t.text\n" +"align 4\n" +"err:\n" +"\tpush\tdword 1\t\t; return failure\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1240 +#, no-wrap +msgid "" +"align 4\n" +"global\t_start\n" +"_start:\n" +"\tadd\tesp, byte 8\t; discard argc and argv[0]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1243 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1255 +#, no-wrap +msgid "" +"\tpop\tecx\n" +"\tjecxz\t.init\t\t; no more arguments\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1249 +#, no-wrap +msgid "" +"\t; ECX contains the path to input file\n" +"\tpush\tdword 0\t\t; O_RDONLY\n" +"\tpush\tecx\n" +"\tsys.open\n" +"\tjc\terr\t\t; open failed\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1252 +#, no-wrap +msgid "" +"\tadd\tesp, byte 8\n" +"\tmov\t[fd.in], eax\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1263 +#, no-wrap +msgid "" +"\t; ECX contains the path to output file\n" +"\tpush\tdword 420\t; file mode (644 octal)\n" +"\tpush\tdword 0200h | 0400h | 01h\n" +"\t; O_CREAT | O_TRUNC | O_WRONLY\n" +"\tpush\tecx\n" +"\tsys.open\n" +"\tjc\terr\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1266 +#, no-wrap +msgid "" +"\tadd\tesp, byte 12\n" +"\tmov\t[fd.out], eax\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1272 +#, no-wrap +msgid "" +".init:\n" +"\tsub\teax, eax\n" +"\tsub\tebx, ebx\n" +"\tsub\tecx, ecx\n" +"\tmov\tedi, obuffer\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1276 +#, no-wrap +msgid "" +".loop:\n" +"\t; read a byte from input file or stdin\n" +"\tcall\tgetchar\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1299 +#, no-wrap +msgid "" +".put:\n" +"\tcall\tputchar\n" +"\tcmp\tal, dl\n" +"\tjne\t.loop\n" +"\tcall\twrite\n" +"\tjmp\tshort .loop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1324 +#, no-wrap +msgid "" +"read:\n" +"\tpush\tdword BUFSIZE\n" +"\tmov\tesi, ibuffer\n" +"\tpush\tesi\n" +"\tpush\tdword [fd.in]\n" +"\tsys.read\n" +"\tadd\tesp, byte 12\n" +"\tmov\tebx, eax\n" +"\tor\teax, eax\n" +"\tje\t.done\n" +"\tsub\teax, eax\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1328 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2561 +#, no-wrap +msgid "" +"align 4\n" +".done:\n" +"\tcall\twrite\t\t; flush output buffer\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1332 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2565 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3819 +#, no-wrap +msgid "" +"\t; close files\n" +"\tpush\tdword [fd.in]\n" +"\tsys.close\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1335 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2568 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3822 +#, no-wrap +msgid "" +"\tpush\tdword [fd.out]\n" +"\tsys.close\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1339 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2572 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3828 +#, no-wrap +msgid "" +"\t; return success\n" +"\tpush\tdword 0\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1359 +#, no-wrap +msgid "" +"align 4\n" +"write:\n" +"\tsub\tedi, ecx\t; start of buffer\n" +"\tpush\tecx\n" +"\tpush\tedi\n" +"\tpush\tdword [fd.out]\n" +"\tsys.write\n" +"\tadd\tesp, byte 12\n" +"\tsub\teax, eax\n" +"\tsub\tecx, ecx\t; buffer is empty now\n" +"\tret\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1363 +msgid "" +"In our `.data` section we now have two new variables, `fd.in` and `fd.out`. " +"We store the input and output file descriptors here." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1365 +msgid "" +"In the `.text` section we have replaced the references to `stdin` and " +"`stdout` with `[fd.in]` and `[fd.out]`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1368 +msgid "" +"The `.text` section now starts with a simple error handler, which does " +"nothing but exit the program with a return value of `1`. The error handler " +"is before `_start` so we are within a short distance from where the errors " +"occur." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1371 +msgid "" +"Naturally, the program execution still begins at `_start`. First, we remove " +"`argc` and `argv[0]` from the stack: They are of no interest to us (in this " +"program, that is)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1377 +msgid "" +"We pop `argv[1]` to `ECX`. This register is particularly suited for " +"pointers, as we can handle NULL pointers with `jecxz`. If `argv[1]` is not " +"NULL, we try to open the file named in the first argument. Otherwise, we " +"continue the program as before: Reading from `stdin`, writing to `stdout`. " +"If we fail to open the input file (e.g., it does not exist), we jump to the " +"error handler and quit." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1382 +msgid "" +"If all went well, we now check for the second argument. If it is there, we " +"open the output file. Otherwise, we send the output to `stdout`. If we " +"fail to open the output file (e.g., it exists and we do not have the write " +"permission), we, again, jump to the error handler." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1384 +msgid "" +"The rest of the code is the same as before, except we close the input and " +"output files before exiting, and, as mentioned, we use `[fd.in]` and `[fd." +"out]`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1386 +msgid "Our executable is now a whopping 768 bytes long." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1389 +msgid "" +"Can we still improve it? Of course! Every program can be improved. Here are " +"a few ideas of what we could do:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1391 +msgid "Have our error handler print a message to `stderr`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1392 +msgid "Add error handlers to the `read` and `write` functions." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1393 +msgid "" +"Close `stdin` when we open an input file, `stdout` when we open an output " +"file." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1394 +msgid "" +"Add command line switches, such as `-i` and `-o`, so we can list the input " +"and output files in any order, or perhaps read from `stdin` and write to a " +"file." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1395 +msgid "Print a usage message if command line arguments are incorrect." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1397 +msgid "" +"I shall leave these enhancements as an exercise to the reader: You already " +"know everything you need to know to implement them." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1399 +#, no-wrap +msgid "UNIX(R) Environment" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1403 +msgid "" +"An important UNIX(R) concept is the environment, which is defined by " +"_environment variables_. Some are set by the system, others by you, yet " +"others by the shell, or any program that loads another program." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1405 +#, no-wrap +msgid "How to Find Environment Variables" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1410 +msgid "" +"I said earlier that when a program starts executing, the stack contains " +"`argc` followed by the NULL-terminated `argv` array, followed by something " +"else. The \"something else\" is the _environment_, or, to be more precise, " +"a NULL-terminated array of pointers to _environment variables_. This is " +"often referred to as `env`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1413 +msgid "" +"The structure of `env` is the same as that of `argv`, a list of memory " +"addresses followed by a NULL (`0`). In this case, there is no `\"envc\"`-we " +"figure out where the array ends by searching for the final NULL." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1416 +msgid "" +"The variables usually come in the `name=value` format, but sometimes the " +"`=value` part may be missing. We need to account for that possibility." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1418 +#, no-wrap +msgid "webvars" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1422 +msgid "" +"I could just show you some code that prints the environment the same way the " +"UNIX(R) env command does. But I thought it would be more interesting to " +"write a simple assembly language CGI utility." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1424 +#, no-wrap +msgid "CGI: a Quick Overview" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1427 +msgid "" +"I have a http://www.whizkidtech.redprince.net/cgi-bin/tutorial[detailed CGI " +"tutorial] on my web site, but here is a very quick overview of CGI:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1429 +msgid "" +"The web server communicates with the CGI program by setting _environment " +"variables_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1430 +msgid "" +"The CGI program sends its output to [.filename]#stdout#. The web server " +"reads it from there." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1431 +msgid "It must start with an HTTP header followed by two blank lines." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1432 +msgid "" +"It then prints the HTML code, or whatever other type of data it is producing." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1437 +msgid "" +"While certain _environment variables_ use standard names, others vary, " +"depending on the web server. That makes webvars quite a useful diagnostic " +"tool." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1440 +#, no-wrap +msgid "The Code" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1444 +msgid "" +"Our webvars program, then, must send out the HTTP header followed by some " +"HTML mark-up. It then must read the _environment variables_ one by one and " +"send them out as part of the HTML page." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1447 +msgid "" +"The code follows. I placed comments and explanations right inside the code:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1484 +#, no-wrap +msgid "" +";;;;;;; webvars.asm ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n" +";\n" +"; Copyright (c) 2000 G. Adam Stanislav\n" +"; All rights reserved.\n" +";\n" +"; Redistribution and use in source and binary forms, with or without\n" +"; modification, are permitted provided that the following conditions\n" +"; are met:\n" +"; 1. Redistributions of source code must retain the above copyright\n" +"; notice, this list of conditions and the following disclaimer.\n" +"; 2. Redistributions in binary form must reproduce the above copyright\n" +"; notice, this list of conditions and the following disclaimer in the\n" +"; documentation and/or other materials provided with the distribution.\n" +";\n" +"; THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND\n" +"; ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE\n" +"; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE\n" +"; ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE\n" +"; FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL\n" +"; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS\n" +"; OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)\n" +"; HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT\n" +"; LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY\n" +"; OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF\n" +"; SUCH DAMAGE.\n" +";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n" +";\n" +"; Version 1.0\n" +";\n" +"; Started:\t 8-Dec-2000\n" +"; Updated:\t 8-Dec-2000\n" +";\n" +";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n" +"%include\t'system.inc'\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1521 +#, no-wrap +msgid "" +"section\t.data\n" +"http\tdb\t'Content-type: text/html', 0Ah, 0Ah\n" +"\tdb\t'<?xml version=\"1.0\" encoding=\"utf-8\"?>', 0Ah\n" +"\tdb\t'<!DOCTYPE html PUBLIC \"-//W3C/DTD XHTML Strict//EN\" '\n" +"\tdb\t'\"DTD/xhtml1-strict.dtd\">', 0Ah\n" +"\tdb\t'<html xmlns=\"http://www.w3.org/1999/xhtml\" '\n" +"\tdb\t'xml.lang=\"en\" lang=\"en\">', 0Ah\n" +"\tdb\t'<head>', 0Ah\n" +"\tdb\t'<title>Web Environment</title>', 0Ah\n" +"\tdb\t'<meta name=\"author\" content=\"G. Adam Stanislav\" />', 0Ah\n" +"\tdb\t'</head>', 0Ah, 0Ah\n" +"\tdb\t'<body bgcolor=\"#ffffff\" text=\"#000000\" link=\"#0000ff\" '\n" +"\tdb\t'vlink=\"#840084\" alink=\"#0000ff\">', 0Ah\n" +"\tdb\t'<div class=\"webvars\">', 0Ah\n" +"\tdb\t'<h1>Web Environment</h1>', 0Ah\n" +"\tdb\t'<p>The following <b>environment variables</b> are defined '\n" +"\tdb\t'on this web server:</p>', 0Ah, 0Ah\n" +"\tdb\t'<table align=\"center\" width=\"80\" border=\"0\" cellpadding=\"10\" '\n" +"\tdb\t'cellspacing=\"0\" class=\"webvars\">', 0Ah\n" +"httplen\tequ\t$-http\n" +"left\tdb\t'<tr>', 0Ah\n" +"\tdb\t'<td class=\"name\"><tt>'\n" +"leftlen\tequ\t$-left\n" +"middle\tdb\t'</tt></td>', 0Ah\n" +"\tdb\t'<td class=\"value\"><tt><b>'\n" +"midlen\tequ\t$-middle\n" +"undef\tdb\t'<i>(undefined)</i>'\n" +"undeflen\tequ\t$-undef\n" +"right\tdb\t'</b></tt></td>', 0Ah\n" +"\tdb\t'</tr>', 0Ah\n" +"rightlen\tequ\t$-right\n" +"wrap\tdb\t'</table>', 0Ah\n" +"\tdb\t'</div>', 0Ah\n" +"\tdb\t'</body>', 0Ah\n" +"\tdb\t'</html>', 0Ah, 0Ah\n" +"wraplen\tequ\t$-wrap\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1531 +#, no-wrap +msgid "" +"section\t.text\n" +"global\t_start\n" +"_start:\n" +"\t; First, send out all the http and xhtml stuff that is\n" +"\t; needed before we start showing the environment\n" +"\tpush\tdword httplen\n" +"\tpush\tdword http\n" +"\tpush\tdword stdout\n" +"\tsys.write\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1535 +#, no-wrap +msgid "" +"\t; Now find how far on the stack the environment pointers\n" +"\t; are. We have 12 bytes we have pushed before \"argc\"\n" +"\tmov\teax, [esp+12]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1550 +#, no-wrap +msgid "" +"\t; We need to remove the following from the stack:\n" +"\t;\n" +"\t;\tThe 12 bytes we pushed for sys.write\n" +"\t;\tThe 4 bytes of argc\n" +"\t;\tThe EAX*4 bytes of argv\n" +"\t;\tThe 4 bytes of the NULL after argv\n" +"\t;\n" +"\t; Total:\n" +"\t;\t20 + eax * 4\n" +"\t;\n" +"\t; Because stack grows down, we need to ADD that many bytes\n" +"\t; to ESP.\n" +"\tlea\tesp, [esp+20+eax*4]\n" +"\tcld\t\t; This should already be the case, but let's be sure.\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1556 +#, no-wrap +msgid "" +"\t; Loop through the environment, printing it out\n" +".loop:\n" +"\tpop\tedi\n" +"\tor\tedi, edi\t; Done yet?\n" +"\tje\tnear .wrap\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1562 +#, no-wrap +msgid "" +"\t; Print the left part of HTML\n" +"\tpush\tdword leftlen\n" +"\tpush\tdword left\n" +"\tpush\tdword stdout\n" +"\tsys.write\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1573 +#, no-wrap +msgid "" +"\t; It may be tempting to search for the '=' in the env string next.\n" +"\t; But it is possible there is no '=', so we search for the\n" +"\t; terminating NUL first.\n" +"\tmov\tesi, edi\t; Save start of string\n" +"\tsub\tecx, ecx\n" +"\tnot\tecx\t\t; ECX = FFFFFFFF\n" +"\tsub\teax, eax\n" +"repne\tscasb\n" +"\tnot\tecx\t\t; ECX = string length + 1\n" +"\tmov\tebx, ecx\t; Save it in EBX\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1580 +#, no-wrap +msgid "" +"\t; Now is the time to find '='\n" +"\tmov\tedi, esi\t; Start of string\n" +"\tmov\tal, '='\n" +"repne\tscasb\n" +"\tnot\tecx\n" +"\tadd\tecx, ebx\t; Length of name\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1585 +#, no-wrap +msgid "" +"\tpush\tecx\n" +"\tpush\tesi\n" +"\tpush\tdword stdout\n" +"\tsys.write\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1591 +#, no-wrap +msgid "" +"\t; Print the middle part of HTML table code\n" +"\tpush\tdword midlen\n" +"\tpush\tdword middle\n" +"\tpush\tdword stdout\n" +"\tsys.write\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1595 +#, no-wrap +msgid "" +"\t; Find the length of the value\n" +"\tnot\tecx\n" +"\tlea\tebx, [ebx+ecx-1]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1599 +#, no-wrap +msgid "" +"\t; Print \"undefined\" if 0\n" +"\tor\tebx, ebx\n" +"\tjne\t.value\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1602 +#, no-wrap +msgid "" +"\tmov\tebx, undeflen\n" +"\tmov\tedi, undef\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1608 +#, no-wrap +msgid "" +".value:\n" +"\tpush\tebx\n" +"\tpush\tedi\n" +"\tpush\tdword stdout\n" +"\tsys.write\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1614 +#, no-wrap +msgid "" +"\t; Print the right part of the table row\n" +"\tpush\tdword rightlen\n" +"\tpush\tdword right\n" +"\tpush\tdword stdout\n" +"\tsys.write\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1617 +#, no-wrap +msgid "" +"\t; Get rid of the 60 bytes we have pushed\n" +"\tadd\tesp, byte 60\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1620 +#, no-wrap +msgid "" +"\t; Get the next variable\n" +"\tjmp\t.loop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1627 +#, no-wrap +msgid "" +".wrap:\n" +"\t; Print the rest of HTML\n" +"\tpush\tdword wraplen\n" +"\tpush\tdword wrap\n" +"\tpush\tdword stdout\n" +"\tsys.write\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1631 +#, no-wrap +msgid "" +"\t; Return success\n" +"\tpush\tdword 0\n" +"\tsys.exit\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1635 +msgid "" +"This code produces a 1,396-byte executable. Most of it is data, i.e., the " +"HTML mark-up we need to send out." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1637 +msgid "Assemble and link it as usual:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1642 +#, no-wrap +msgid "" +"% nasm -f elf webvars.asm\n" +"% ld -s -o webvars webvars.o\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1646 +msgid "" +"To use it, you need to upload [.filename]#webvars# to your web server. " +"Depending on how your web server is set up, you may have to store it in a " +"special [.filename]#cgi-bin# directory, or perhaps rename it with a [." +"filename]#.cgi# extension." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1650 +msgid "" +"Then you need to use your browser to view its output. To see its output on " +"my web server, please go to http://www.int80h.org/webvars/[http://www.int80h." +"org/webvars/]. If curious about the additional environment variables " +"present in a password protected web directory, go to http://www.int80h.org/" +"private/[http://www.int80h.org/private/], using the name `asm` and password " +"`programmer`." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1652 +#, no-wrap +msgid "Working with Files" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1657 +msgid "" +"We have already done some basic file work: We know how to open and close " +"them, how to read and write them using buffers. But UNIX(R) offers much " +"more functionality when it comes to files. We will examine some of it in " +"this section, and end up with a nice file conversion utility." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1660 +msgid "" +"Indeed, let us start at the end, that is, with the file conversion utility. " +"It always makes programming easier when we know from the start what the end " +"product is supposed to do." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1666 +msgid "" +"One of the first programs I wrote for UNIX(R) was link:ftp://ftp.int80h.org/" +"unix/tuc/[tuc], a text-to-UNIX(R) file converter. It converts a text file " +"from other operating systems to a UNIX(R) text file. In other words, it " +"changes from different kind of line endings to the newline convention of " +"UNIX(R). It saves the output in a different file. Optionally, it converts " +"a UNIX(R) text file to a DOS text file." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1670 +msgid "" +"I have used tuc extensively, but always only to convert from some other OS " +"to UNIX(R), never the other way. I have always wished it would just " +"overwrite the file instead of me having to send the output to a different " +"file. Most of the time, I end up using it like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1675 +#, no-wrap +msgid "" +"% tuc myfile tempfile\n" +"% mv tempfile myfile\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1678 +msgid "" +"It would be nice to have a ftuc, i.e., _fast tuc_, and use it like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1682 +#, no-wrap +msgid "% ftuc myfile\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1685 +msgid "" +"In this chapter, then, we will write ftuc in assembly language (the original " +"tuc is in C), and study various file-oriented kernel services in the process." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1687 +msgid "" +"At first sight, such a file conversion is very simple: All you have to do is " +"strip the carriage returns, right?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1689 +msgid "" +"If you answered yes, think again: That approach will work most of the time " +"(at least with MS DOS text files), but will fail occasionally." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1694 +msgid "" +"The problem is that not all non UNIX(R) text files end their line with the " +"carriage return / line feed sequence. Some use carriage returns without " +"line feeds. Others combine several blank lines into a single carriage " +"return followed by several line feeds. And so on." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1696 +msgid "" +"A text file converter, then, must be able to handle any possible line " +"endings:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1698 +msgid "carriage return / line feed" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1699 +msgid "carriage return" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1700 +msgid "line feed / carriage return" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1701 +msgid "line feed" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1703 +msgid "" +"It should also handle files that use some kind of a combination of the above " +"(e.g., carriage return followed by several line feeds)." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1705 +#, no-wrap +msgid "Finite State Machine" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1712 +msgid "" +"The problem is easily solved by the use of a technique called _finite state " +"machine_, originally developed by the designers of digital electronic " +"circuits. A _finite state machine_ is a digital circuit whose output is " +"dependent not only on its input but on its previous input, i.e., on its " +"state. The microprocessor is an example of a _finite state machine_: Our " +"assembly language code is assembled to machine language in which some " +"assembly language code produces a single byte of machine language, while " +"others produce several bytes. As the microprocessor fetches the bytes from " +"the memory one by one, some of them simply change its state rather than " +"produce some output. When all the bytes of the op code are fetched, the " +"microprocessor produces some output, or changes the value of a register, etc." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1715 +msgid "" +"Because of that, all software is essentially a sequence of state " +"instructions for the microprocessor. Nevertheless, the concept of _finite " +"state machine_ is useful in software design as well." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1718 +msgid "" +"Our text file converter can be designer as a _finite state machine_ with " +"three possible states. We could call them states 0-2, but it will make our " +"life easier if we give them symbolic names:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1720 +msgid "ordinary" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1721 +msgid "cr" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1722 +msgid "lf" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1724 +msgid "" +"Our program will start in the ordinary state. During this state, the program " +"action depends on its input as follows:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1727 +msgid "" +"If the input is anything other than a carriage return or line feed, the " +"input is simply passed on to the output. The state remains unchanged." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1729 +msgid "" +"If the input is a carriage return, the state is changed to cr. The input is " +"then discarded, i.e., no output is made." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1731 +msgid "" +"If the input is a line feed, the state is changed to lf. The input is then " +"discarded." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1734 +msgid "" +"Whenever we are in the cr state, it is because the last input was a carriage " +"return, which was unprocessed. What our software does in this state again " +"depends on the current input:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1736 +msgid "" +"If the input is anything other than a carriage return or line feed, output a " +"line feed, then output the input, then change the state to ordinary." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1737 +msgid "" +"If the input is a carriage return, we have received two (or more) carriage " +"returns in a row. We discard the input, we output a line feed, and leave the " +"state unchanged." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1738 +msgid "" +"If the input is a line feed, we output the line feed and change the state to " +"ordinary. Note that this is not the same as the first case above - if we " +"tried to combine them, we would be outputting two line feeds instead of one." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1742 +msgid "" +"Finally, we are in the lf state after we have received a line feed that was " +"not preceded by a carriage return. This will happen when our file already " +"is in UNIX(R) format, or whenever several lines in a row are expressed by a " +"single carriage return followed by several line feeds, or when line ends " +"with a line feed / carriage return sequence. Here is how we need to handle " +"our input in this state:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1744 +msgid "" +"If the input is anything other than a carriage return or line feed, we " +"output a line feed, then output the input, then change the state to " +"ordinary. This is exactly the same action as in the cr state upon receiving " +"the same kind of input." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1745 +msgid "" +"If the input is a carriage return, we discard the input, we output a line " +"feed, then change the state to ordinary." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1746 +msgid "" +"If the input is a line feed, we output the line feed, and leave the state " +"unchanged." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1748 +#, no-wrap +msgid "The Final State" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1753 +msgid "" +"The above _finite state machine_ works for the entire file, but leaves the " +"possibility that the final line end will be ignored. That will happen " +"whenever the file ends with a single carriage return or a single line feed. " +"I did not think of it when I wrote tuc, just to discover that occasionally " +"it strips the last line ending." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1756 +msgid "" +"This problem is easily fixed by checking the state after the entire file was " +"processed. If the state is not ordinary, we simply need to output one last " +"line feed." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1762 +msgid "" +"Now that we have expressed our algorithm as a _finite state machine_, we " +"could easily design a dedicated digital electronic circuit (a \"chip\") to " +"do the conversion for us. Of course, doing so would be considerably more " +"expensive than writing an assembly language program." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1765 +#, no-wrap +msgid "The Output Counter" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1770 +msgid "" +"Because our file conversion program may be combining two characters into " +"one, we need to use an output counter. We initialize it to `0`, and " +"increase it every time we send a character to the output. At the end of the " +"program, the counter will tell us what size we need to set the file to." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1772 +#, no-wrap +msgid "Implementing FSM in Software" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1776 +msgid "" +"The hardest part of working with a _finite state machine_ is analyzing the " +"problem and expressing it as a _finite state machine_. That accomplished, " +"the software almost writes itself." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1779 +msgid "" +"In a high-level language, such as C, there are several main approaches. One " +"is to use a `switch` statement which chooses what function should be run. " +"For example," +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1794 +#, no-wrap +msgid "" +"switch (state) {\n" +"\tdefault:\n" +"\tcase REGULAR:\n" +"\t\tregular(inputchar);\n" +"\t\tbreak;\n" +"\tcase CR:\n" +"\t\tcr(inputchar);\n" +"\t\tbreak;\n" +"\tcase LF:\n" +"\t\tlf(inputchar);\n" +"\t\tbreak;\n" +"\t}\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1797 +msgid "" +"Another approach is by using an array of function pointers, something like " +"this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1801 +#, no-wrap +msgid "(output[state])(inputchar);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1804 +msgid "" +"Yet another is to have `state` be a function pointer, set to point at the " +"appropriate function:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1808 +#, no-wrap +msgid "(*state)(inputchar);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1812 +msgid "" +"This is the approach we will use in our program because it is very easy to " +"do in assembly language, and very fast, too. We will simply keep the " +"address of the right procedure in `EBX`, and then just issue:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1816 +#, no-wrap +msgid "call\tebx\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1820 +msgid "" +"This is possibly faster than hardcoding the address in the code because the " +"microprocessor does not have to fetch the address from the memory-it is " +"already stored in one of its registers. I said _possibly_ because with the " +"caching modern microprocessors do, either way may be equally fast." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1822 +#, no-wrap +msgid "Memory Mapped Files" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1826 +msgid "" +"Because our program works on a single file, we cannot use the approach that " +"worked for us before, i.e., to read from an input file and to write to an " +"output file." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1834 +msgid "" +"UNIX(R) allows us to map a file, or a section of a file, into memory. To do " +"that, we first need to open the file with the appropriate read/write flags. " +"Then we use the `mmap` system call to map it into the memory. One nice " +"thing about `mmap` is that it automatically works with virtual memory: We " +"can map more of the file into the memory than we have physical memory " +"available, yet still access it through regular memory op codes, such as " +"`mov`, `lods`, and `stos`. Whatever changes we make to the memory image of " +"the file will be written to the file by the system. We do not even have to " +"keep the file open: As long as it stays mapped, we can read from it and " +"write to it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1837 +msgid "" +"The 32-bit Intel microprocessors can access up to four gigabytes of memory - " +"physical or virtual. The FreeBSD system allows us to use up to a half of it " +"for file mapping." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1841 +msgid "" +"For simplicity sake, in this tutorial we will only convert files that can be " +"mapped into the memory in their entirety. There are probably not too many " +"text files that exceed two gigabytes in size. If our program encounters " +"one, it will simply display a message suggesting we use the original tuc " +"instead." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1847 +msgid "" +"If you examine your copy of [.filename]#syscalls.master#, you will find two " +"separate syscalls named `mmap`. This is because of evolution of UNIX(R): " +"There was the traditional BSD `mmap`, syscall 71. That one was superseded " +"by the POSIX(R) `mmap`, syscall 197. The FreeBSD system supports both " +"because older programs were written by using the original BSD version. But " +"new software uses the POSIX(R) version, which is what we will use." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1849 +msgid "The [.filename]#syscalls.master# lists the POSIX(R) version like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1854 +#, no-wrap +msgid "" +"197\tSTD\tBSD\t{ caddr_t mmap(caddr_t addr, size_t len, int prot, \\\n" +"\t\t\t int flags, int fd, long pad, off_t pos); }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1858 +msgid "" +"This differs slightly from what man:mmap[2] says. That is because man:" +"mmap[2] describes the C version." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1862 +msgid "" +"The difference is in the `long pad` argument, which is not present in the C " +"version. However, the FreeBSD syscalls add a 32-bit pad after ``push``ing a " +"64-bit argument. In this case, `off_t` is a 64-bit value." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1864 +msgid "" +"When we are finished working with a memory-mapped file, we unmap it with the " +"`munmap` syscall:" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1868 +msgid "" +"For an in-depth treatment of `mmap`, see W. Richard Stevens' http://www." +"int80h.org/cgi-bin/isbn?isbn=0130810819[Unix Network Programming, Volume 2, " +"Chapter 12]." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1871 +#, no-wrap +msgid "Determining File Size" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1874 +msgid "" +"Because we need to tell `mmap` how many bytes of the file to map into the " +"memory, and because we want to map the entire file, we need to determine the " +"size of the file." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1877 +msgid "" +"We can use the `fstat` syscall to get all the information about an open file " +"that the system can give us. That includes the file size." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1880 +msgid "" +"Again, [.filename]#syscalls.master# lists two versions of `fstat`, a " +"traditional one (syscall 62), and a POSIX(R) one (syscall 189). Naturally, " +"we will use the POSIX(R) version:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1884 +#, no-wrap +msgid "189\tSTD\tPOSIX\t{ int fstat(int fd, struct stat *sb); }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1888 +msgid "" +"This is a very straightforward call: We pass to it the address of a `stat` " +"structure and the descriptor of an open file. It will fill out the contents " +"of the `stat` structure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1891 +msgid "" +"I do, however, have to say that I tried to declare the `stat` structure in " +"the `.bss` section, and `fstat` did not like it: It set the carry flag " +"indicating an error. After I changed the code to allocate the structure on " +"the stack, everything was working fine." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1893 +#, no-wrap +msgid "Changing the File Size" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1897 +msgid "" +"Because our program may combine carriage return / line feed sequences into " +"straight line feeds, our output may be smaller than our input. However, " +"since we are placing our output into the same file we read the input from, " +"we may have to change the size of the file." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1900 +msgid "" +"The `ftruncate` system call allows us to do just that. Despite its somewhat " +"misleading name, the `ftruncate` system call can be used to both truncate " +"the file (make it smaller) and to grow it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1903 +msgid "" +"And yes, we will find two versions of `ftruncate` in [.filename]#syscalls." +"master#, an older one (130), and a newer one (201). We will use the newer " +"one:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1907 +#, no-wrap +msgid "201\tSTD\tBSD\t{ int ftruncate(int fd, int pad, off_t length); }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1910 +msgid "Please note that this one contains a `int pad` again." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1912 +#, no-wrap +msgid "ftuc" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1917 +msgid "" +"We now know everything we need to write ftuc. We start by adding some new " +"lines in [.filename]#system.inc#. First, we define some constants and " +"structures, somewhere at or near the beginning of the file:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1924 +#, no-wrap +msgid "" +";;;;;;; open flags\n" +"%define\tO_RDONLY\t0\n" +"%define\tO_WRONLY\t1\n" +"%define\tO_RDWR\t2\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1933 +#, no-wrap +msgid "" +";;;;;;; mmap flags\n" +"%define\tPROT_NONE\t0\n" +"%define\tPROT_READ\t1\n" +"%define\tPROT_WRITE\t2\n" +"%define\tPROT_EXEC\t4\n" +";;\n" +"%define\tMAP_SHARED\t0001h\n" +"%define\tMAP_PRIVATE\t0002h\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1957 +#, no-wrap +msgid "" +";;;;;;; stat structure\n" +"struc\tstat\n" +"st_dev\t\tresd\t1\t; = 0\n" +"st_ino\t\tresd\t1\t; = 4\n" +"st_mode\t\tresw\t1\t; = 8, size is 16 bits\n" +"st_nlink\tresw\t1\t; = 10, ditto\n" +"st_uid\t\tresd\t1\t; = 12\n" +"st_gid\t\tresd\t1\t; = 16\n" +"st_rdev\t\tresd\t1\t; = 20\n" +"st_atime\tresd\t1\t; = 24\n" +"st_atimensec\tresd\t1\t; = 28\n" +"st_mtime\tresd\t1\t; = 32\n" +"st_mtimensec\tresd\t1\t; = 36\n" +"st_ctime\tresd\t1\t; = 40\n" +"st_ctimensec\tresd\t1\t; = 44\n" +"st_size\t\tresd\t2\t; = 48, size is 64 bits\n" +"st_blocks\tresd\t2\t; = 56, ditto\n" +"st_blksize\tresd\t1\t; = 64\n" +"st_flags\tresd\t1\t; = 68\n" +"st_gen\t\tresd\t1\t; = 72\n" +"st_lspare\tresd\t1\t; = 76\n" +"st_qspare\tresd\t4\t; = 80\n" +"endstruc\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1960 +msgid "We define the new syscalls:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1967 +#, no-wrap +msgid "" +"%define\tSYS_mmap\t197\n" +"%define\tSYS_munmap\t73\n" +"%define\tSYS_fstat\t189\n" +"%define\tSYS_ftruncate\t201\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1970 +msgid "We add the macros for their use:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1976 +#, no-wrap +msgid "" +"%macro\tsys.mmap\t0\n" +"\tsystem\tSYS_mmap\n" +"%endmacro\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1980 +#, no-wrap +msgid "" +"%macro\tsys.munmap\t0\n" +"\tsystem\tSYS_munmap\n" +"%endmacro\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1984 +#, no-wrap +msgid "" +"%macro\tsys.ftruncate\t0\n" +"\tsystem\tSYS_ftruncate\n" +"%endmacro\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1988 +#, no-wrap +msgid "" +"%macro\tsys.fstat\t0\n" +"\tsystem\tSYS_fstat\n" +"%endmacro\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:1991 +msgid "And here is our code:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2004 +#, no-wrap +msgid "" +";;;;;;; Fast Text-to-Unix Conversion (ftuc.asm) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n" +";;\n" +";; Started:\t21-Dec-2000\n" +";; Updated:\t22-Dec-2000\n" +";;\n" +";; Copyright 2000 G. Adam Stanislav.\n" +";; All rights reserved.\n" +";;\n" +";;;;;;; v.1 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n" +"%include\t'system.inc'\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2018 +#, no-wrap +msgid "" +"section\t.data\n" +"\tdb\t'Copyright 2000 G. Adam Stanislav.', 0Ah\n" +"\tdb\t'All rights reserved.', 0Ah\n" +"usg\tdb\t'Usage: ftuc filename', 0Ah\n" +"usglen\tequ\t$-usg\n" +"co\tdb\t\"ftuc: Can't open file.\", 0Ah\n" +"colen\tequ\t$-co\n" +"fae\tdb\t'ftuc: File access error.', 0Ah\n" +"faelen\tequ\t$-fae\n" +"ftl\tdb\t'ftuc: File too long, use regular tuc instead.', 0Ah\n" +"ftllen\tequ\t$-ftl\n" +"mae\tdb\t'ftuc: Memory allocation error.', 0Ah\n" +"maelen\tequ\t$-mae\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2020 +#, no-wrap +msgid "section\t.text\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2026 +#, no-wrap +msgid "" +"align 4\n" +"memerr:\n" +"\tpush\tdword maelen\n" +"\tpush\tdword mae\n" +"\tjmp\tshort error\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2032 +#, no-wrap +msgid "" +"align 4\n" +"toolong:\n" +"\tpush\tdword ftllen\n" +"\tpush\tdword ftl\n" +"\tjmp\tshort error\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2038 +#, no-wrap +msgid "" +"align 4\n" +"facerr:\n" +"\tpush\tdword faelen\n" +"\tpush\tdword fae\n" +"\tjmp\tshort error\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2044 +#, no-wrap +msgid "" +"align 4\n" +"cantopen:\n" +"\tpush\tdword colen\n" +"\tpush\tdword co\n" +"\tjmp\tshort error\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2049 +#, no-wrap +msgid "" +"align 4\n" +"usage:\n" +"\tpush\tdword usglen\n" +"\tpush\tdword usg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2053 +#, no-wrap +msgid "" +"error:\n" +"\tpush\tdword stderr\n" +"\tsys.write\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2056 +#, no-wrap +msgid "" +"\tpush\tdword 1\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2064 +#, no-wrap +msgid "" +"align 4\n" +"global\t_start\n" +"_start:\n" +"\tpop\teax\t\t; argc\n" +"\tpop\teax\t\t; program name\n" +"\tpop\tecx\t\t; file to convert\n" +"\tjecxz\tusage\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2068 +#, no-wrap +msgid "" +"\tpop\teax\n" +"\tor\teax, eax\t; Too many arguments?\n" +"\tjne\tusage\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2074 +#, no-wrap +msgid "" +"\t; Open the file\n" +"\tpush\tdword O_RDWR\n" +"\tpush\tecx\n" +"\tsys.open\n" +"\tjc\tcantopen\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2076 +#, no-wrap +msgid "\tmov\tebp, eax\t; Save fd\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2079 +#, no-wrap +msgid "" +"\tsub\tesp, byte stat_size\n" +"\tmov\tebx, esp\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2085 +#, no-wrap +msgid "" +"\t; Find file size\n" +"\tpush\tebx\n" +"\tpush\tebp\t\t; fd\n" +"\tsys.fstat\n" +"\tjc\tfacerr\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2087 +#, no-wrap +msgid "\tmov\tedx, [ebx + st_size + 4]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2095 +#, no-wrap +msgid "" +"\t; File is too long if EDX != 0 ...\n" +"\tor\tedx, edx\n" +"\tjne\tnear toolong\n" +"\tmov\tecx, [ebx + st_size]\n" +"\t; ... or if it is above 2 GB\n" +"\tor\tecx, ecx\n" +"\tjs\tnear toolong\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2098 +#, no-wrap +msgid "" +"\t; Do nothing if the file is 0 bytes in size\n" +"\tjecxz\t.quit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2110 +#, no-wrap +msgid "" +"\t; Map the entire file in memory\n" +"\tpush\tedx\n" +"\tpush\tedx\t\t; starting at offset 0\n" +"\tpush\tedx\t\t; pad\n" +"\tpush\tebp\t\t; fd\n" +"\tpush\tdword MAP_SHARED\n" +"\tpush\tdword PROT_READ | PROT_WRITE\n" +"\tpush\tecx\t\t; entire file size\n" +"\tpush\tedx\t\t; let system decide on the address\n" +"\tsys.mmap\n" +"\tjc\tnear memerr\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2115 +#, no-wrap +msgid "" +"\tmov\tedi, eax\n" +"\tmov\tesi, eax\n" +"\tpush\tecx\t\t; for SYS_munmap\n" +"\tpush\tedi\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2120 +#, no-wrap +msgid "" +"\t; Use EBX for state machine\n" +"\tmov\tebx, ordinary\n" +"\tmov\tah, 0Ah\n" +"\tcld\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2125 +#, no-wrap +msgid "" +".loop:\n" +"\tlodsb\n" +"\tcall\tebx\n" +"\tloop\t.loop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2128 +#, no-wrap +msgid "" +"\tcmp\tebx, ordinary\n" +"\tje\t.filesize\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2133 +#, no-wrap +msgid "" +"\t; Output final lf\n" +"\tmov\tal, ah\n" +"\tstosb\n" +"\tinc\tedx\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2141 +#, no-wrap +msgid "" +".filesize:\n" +"\t; truncate file to new size\n" +"\tpush\tdword 0\t\t; high dword\n" +"\tpush\tedx\t\t; low dword\n" +"\tpush\teax\t\t; pad\n" +"\tpush\tebp\n" +"\tsys.ftruncate\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2144 +#, no-wrap +msgid "" +"\t; close it (ebp still pushed)\n" +"\tsys.close\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2147 +#, no-wrap +msgid "" +"\tadd\tesp, byte 16\n" +"\tsys.munmap\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2151 +#, no-wrap +msgid "" +".quit:\n" +"\tpush\tdword 0\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2156 +#, no-wrap +msgid "" +"align 4\n" +"ordinary:\n" +"\tcmp\tal, 0Dh\n" +"\tje\t.cr\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2159 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2181 +#, no-wrap +msgid "" +"\tcmp\tal, ah\n" +"\tje\t.lf\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2163 +#, no-wrap +msgid "" +"\tstosb\n" +"\tinc\tedx\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2168 +#, no-wrap +msgid "" +"align 4\n" +".cr:\n" +"\tmov\tebx, cr\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2173 +#, no-wrap +msgid "" +"align 4\n" +".lf:\n" +"\tmov\tebx, lf\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2178 +#, no-wrap +msgid "" +"align 4\n" +"cr:\n" +"\tcmp\tal, 0Dh\n" +"\tje\t.cr\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2185 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2213 +#, no-wrap +msgid "" +"\txchg\tal, ah\n" +"\tstosb\n" +"\tinc\tedx\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2188 +#, no-wrap +msgid "" +"\txchg\tal, ah\n" +"\t; fall through\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2194 +#, no-wrap +msgid "" +".lf:\n" +"\tstosb\n" +"\tinc\tedx\n" +"\tmov\tebx, ordinary\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2201 +#, no-wrap +msgid "" +"align 4\n" +".cr:\n" +"\tmov\tal, ah\n" +"\tstosb\n" +"\tinc\tedx\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2206 +#, no-wrap +msgid "" +"align 4\n" +"lf:\n" +"\tcmp\tal, ah\n" +"\tje\t.lf\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2209 +#, no-wrap +msgid "" +"\tcmp\tal, 0Dh\n" +"\tje\t.cr\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2219 +#, no-wrap +msgid "" +"\txchg\tal, ah\n" +"\tstosb\n" +"\tinc\tedx\n" +"\tmov\tebx, ordinary\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2225 +#, no-wrap +msgid "" +"align 4\n" +".cr:\n" +"\tmov\tebx, ordinary\n" +"\tmov\tal, ah\n" +"\t; fall through\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2230 +#, no-wrap +msgid "" +".lf:\n" +"\tstosb\n" +"\tinc\tedx\n" +"\tret\n" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2237 +msgid "" +"Do not use this program on files stored on a disk formatted by MS-DOS(R) or " +"Windows(R). There seems to be a subtle bug in the FreeBSD code when using " +"`mmap` on these drives mounted under FreeBSD: If the file is over a certain " +"size, `mmap` will just fill the memory with zeros, and then copy them to the " +"file overwriting its contents." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2240 +#, no-wrap +msgid "One-Pointed Mind" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2243 +msgid "" +"As a student of Zen, I like the idea of a one-pointed mind: Do one thing at " +"a time, and do it well." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2246 +msgid "" +"This, indeed, is very much how UNIX(R) works as well. While a typical " +"Windows(R) application is attempting to do everything imaginable (and is, " +"therefore, riddled with bugs), a typical UNIX(R) program does only one " +"thing, and it does it well." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2248 +msgid "" +"The typical UNIX(R) user then essentially assembles his own applications by " +"writing a shell script which combines the various existing programs by " +"piping the output of one program to the input of another." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2250 +msgid "" +"When writing your own UNIX(R) software, it is generally a good idea to see " +"what parts of the problem you need to solve can be handled by existing " +"programs, and only write your own programs for that part of the problem that " +"you do not have an existing solution for." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2252 +#, no-wrap +msgid "CSV" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2255 +msgid "" +"I will illustrate this principle with a specific real-life example I was " +"faced with recently:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2259 +msgid "" +"I needed to extract the 11th field of each record from a database I " +"downloaded from a web site. The database was a CSV file, i.e., a list of " +"_comma-separated values_. That is quite a standard format for sharing data " +"among people who may be using different database software." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2262 +msgid "" +"The first line of the file contains the list of various fields separated by " +"commas. The rest of the file contains the data listed line by line, with " +"values separated by commas." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2264 +msgid "" +"I tried awk, using the comma as a separator. But because several lines " +"contained a quoted comma, awk was extracting the wrong field from those " +"lines." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2267 +msgid "" +"Therefore, I needed to write my own software to extract the 11th field from " +"the CSV file. However, going with the UNIX(R) spirit, I only needed to " +"write a simple filter that would do the following:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2269 +msgid "Remove the first line from the file;" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2270 +msgid "Change all unquoted commas to a different character;" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2271 +msgid "Remove all quotation marks." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2273 +msgid "" +"Strictly speaking, I could use sed to remove the first line from the file, " +"but doing so in my own program was very easy, so I decided to do it and " +"reduce the size of the pipeline." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2277 +msgid "" +"At any rate, writing a program like this took me about 20 minutes. Writing " +"a program that extracts the 11th field from the CSV file would take a lot " +"longer, and I could not reuse it to extract some other field from some other " +"database." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2279 +msgid "" +"This time I decided to let it do a little more work than a typical tutorial " +"program would:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2281 +msgid "It parses its command line for options;" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2282 +msgid "It displays proper usage if it finds wrong arguments;" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2283 +msgid "It produces meaningful error messages." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2285 +msgid "Here is its usage message:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2289 +#, no-wrap +msgid "Usage: csv [-t<delim>] [-c<comma>] [-p] [-o <outfile>] [-i <infile>]\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2292 +msgid "All parameters are optional, and can appear in any order." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2296 +msgid "" +"The `-t` parameter declares what to replace the commas with. The `tab` is " +"the default here. For example, `-t;` will replace all unquoted commas with " +"semicolons." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2300 +msgid "" +"I did not need the `-c` option, but it may come in handy in the future. It " +"lets me declare that I want a character other than a comma replaced with " +"something else. For example, `-c@` will replace all at signs (useful if you " +"want to split a list of email addresses to their user names and domains)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2303 +msgid "" +"The `-p` option preserves the first line, i.e., it does not delete it. By " +"default, we delete the first line because in a CSV file it contains the " +"field names rather than data." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2306 +msgid "" +"The `-i` and `-o` options let me specify the input and the output files. " +"Defaults are [.filename]#stdin# and [.filename]#stdout#, so this is a " +"regular UNIX(R) filter." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2309 +msgid "" +"I made sure that both `-i filename` and `-ifilename` are accepted. I also " +"made sure that only one input and one output files may be specified." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2311 +msgid "To get the 11th field of each record, I can now do:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2315 +#, no-wrap +msgid "% csv '-t;' data.csv | awk '-F;' '{print $11}'\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2318 +msgid "" +"The code stores the options (except for the file descriptors) in `EDX`: The " +"comma in `DH`, the new separator in `DL`, and the flag for the `-p` option " +"in the highest bit of `EDX`, so a check for its sign will give us a quick " +"decision what to do." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2320 +msgid "Here is the code:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2334 +#, no-wrap +msgid "" +";;;;;;; csv.asm ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n" +";\n" +"; Convert a comma-separated file to a something-else separated file.\n" +";\n" +"; Started:\t31-May-2001\n" +"; Updated:\t 1-Jun-2001\n" +";\n" +"; Copyright (c) 2001 G. Adam Stanislav\n" +"; All rights reserved.\n" +";\n" +";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2348 +#, no-wrap +msgid "" +"section\t.data\n" +"fd.in\tdd\tstdin\n" +"fd.out\tdd\tstdout\n" +"usg\tdb\t'Usage: csv [-t<delim>] [-c<comma>] [-p] [-o <outfile>] [-i <infile>]', 0Ah\n" +"usglen\tequ\t$-usg\n" +"iemsg\tdb\t\"csv: Can't open input file\", 0Ah\n" +"iemlen\tequ\t$-iemsg\n" +"oemsg\tdb\t\"csv: Can't create output file\", 0Ah\n" +"oemlen\tequ\t$-oemsg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2362 +#, no-wrap +msgid "" +"section\t.text\n" +"align 4\n" +"ierr:\n" +"\tpush\tdword iemlen\n" +"\tpush\tdword iemsg\n" +"\tpush\tdword stderr\n" +"\tsys.write\n" +"\tpush\tdword 1\t\t; return failure\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2371 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3420 +#, no-wrap +msgid "" +"align 4\n" +"oerr:\n" +"\tpush\tdword oemlen\n" +"\tpush\tdword oemsg\n" +"\tpush\tdword stderr\n" +"\tsys.write\n" +"\tpush\tdword 2\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2380 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3429 +#, no-wrap +msgid "" +"align 4\n" +"usage:\n" +"\tpush\tdword usglen\n" +"\tpush\tdword usg\n" +"\tpush\tdword stderr\n" +"\tsys.write\n" +"\tpush\tdword 3\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2386 +#, no-wrap +msgid "" +"align 4\n" +"global\t_start\n" +"_start:\n" +"\tadd\tesp, byte 8\t; discard argc and argv[0]\n" +"\tmov\tedx, (',' << 8) | 9\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2391 +#, no-wrap +msgid "" +".arg:\n" +"\tpop\tecx\n" +"\tor\tecx, ecx\n" +"\tje\tnear .init\t\t; no more arguments\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2395 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3444 +#, no-wrap +msgid "" +"\t; ECX contains the pointer to an argument\n" +"\tcmp\tbyte [ecx], '-'\n" +"\tjne\tusage\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2398 +#, no-wrap +msgid "" +"\tinc\tecx\n" +"\tmov\tax, [ecx]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2402 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3452 +#, no-wrap +msgid "" +".o:\n" +"\tcmp\tal, 'o'\n" +"\tjne\t.i\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2406 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3456 +#, no-wrap +msgid "" +"\t; Make sure we are not asked for the output file twice\n" +"\tcmp\tdword [fd.out], stdout\n" +"\tjne\tusage\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2411 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3461 +#, no-wrap +msgid "" +"\t; Find the path to output file - it is either at [ECX+1],\n" +"\t; i.e., -ofile --\n" +"\t; or in the next argument,\n" +"\t; i.e., -o file\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2417 +#, no-wrap +msgid "" +"\tinc\tecx\n" +"\tor\tah, ah\n" +"\tjne\t.openoutput\n" +"\tpop\tecx\n" +"\tjecxz\tusage\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2425 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3474 +#, no-wrap +msgid "" +".openoutput:\n" +"\tpush\tdword 420\t; file mode (644 octal)\n" +"\tpush\tdword 0200h | 0400h | 01h\n" +"\t; O_CREAT | O_TRUNC | O_WRONLY\n" +"\tpush\tecx\n" +"\tsys.open\n" +"\tjc\tnear oerr\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2429 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3478 +#, no-wrap +msgid "" +"\tadd\tesp, byte 12\n" +"\tmov\t[fd.out], eax\n" +"\tjmp\tshort .arg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2433 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3482 +#, no-wrap +msgid "" +".i:\n" +"\tcmp\tal, 'i'\n" +"\tjne\t.p\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2437 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3486 +#, no-wrap +msgid "" +"\t; Make sure we are not asked twice\n" +"\tcmp\tdword [fd.in], stdin\n" +"\tjne\tnear usage\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2445 +#, no-wrap +msgid "" +"\t; Find the path to the input file\n" +"\tinc\tecx\n" +"\tor\tah, ah\n" +"\tjne\t.openinput\n" +"\tpop\tecx\n" +"\tor\tecx, ecx\n" +"\tje near usage\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2451 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3499 +#, no-wrap +msgid "" +".openinput:\n" +"\tpush\tdword 0\t\t; O_RDONLY\n" +"\tpush\tecx\n" +"\tsys.open\n" +"\tjc\tnear ierr\t\t; open failed\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2455 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3503 +#, no-wrap +msgid "" +"\tadd\tesp, byte 8\n" +"\tmov\t[fd.in], eax\n" +"\tjmp\t.arg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2463 +#, no-wrap +msgid "" +".p:\n" +"\tcmp\tal, 'p'\n" +"\tjne\t.t\n" +"\tor\tah, ah\n" +"\tjne\tnear usage\n" +"\tor\tedx, 1 << 31\n" +"\tjmp\t.arg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2471 +#, no-wrap +msgid "" +".t:\n" +"\tcmp\tal, 't'\t\t; redefine output delimiter\n" +"\tjne\t.c\n" +"\tor\tah, ah\n" +"\tje\tnear usage\n" +"\tmov\tdl, ah\n" +"\tjmp\t.arg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2479 +#, no-wrap +msgid "" +".c:\n" +"\tcmp\tal, 'c'\n" +"\tjne\tnear usage\n" +"\tor\tah, ah\n" +"\tje\tnear usage\n" +"\tmov\tdh, ah\n" +"\tjmp\t.arg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2486 +#, no-wrap +msgid "" +"align 4\n" +".init:\n" +"\tsub\teax, eax\n" +"\tsub\tebx, ebx\n" +"\tsub\tecx, ecx\n" +"\tmov\tedi, obuffer\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2490 +#, no-wrap +msgid "" +"\t; See if we are to preserve the first line\n" +"\tor\tedx, edx\n" +"\tjs\t.loop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2496 +#, no-wrap +msgid "" +".firstline:\n" +"\t; get rid of the first line\n" +"\tcall\tgetchar\n" +"\tcmp\tal, 0Ah\n" +"\tjne\t.firstline\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2504 +#, no-wrap +msgid "" +"\t; is it a comma (or whatever the user asked for)?\n" +"\tcmp\tal, dh\n" +"\tjne\t.quote\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2507 +#, no-wrap +msgid "" +"\t; Replace the comma with a tab (or whatever the user wants)\n" +"\tmov\tal, dl\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2515 +#, no-wrap +msgid "" +".quote:\n" +"\tcmp\tal, '\"'\n" +"\tjne\t.put\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2522 +#, no-wrap +msgid "" +"\t; Print everything until you get another quote or EOL. If it\n" +"\t; is a quote, skip it. If it is EOL, print it.\n" +".qloop:\n" +"\tcall\tgetchar\n" +"\tcmp\tal, '\"'\n" +"\tje\t.loop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2525 +#, no-wrap +msgid "" +"\tcmp\tal, 0Ah\n" +"\tje\t.put\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2528 +#, no-wrap +msgid "" +"\tcall\tputchar\n" +"\tjmp\tshort .qloop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2544 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3859 +#, no-wrap +msgid "" +"read:\n" +"\tjecxz\t.read\n" +"\tcall\twrite\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2557 +#, no-wrap +msgid "" +".read:\n" +"\tpush\tdword BUFSIZE\n" +"\tmov\tesi, ibuffer\n" +"\tpush\tesi\n" +"\tpush\tdword [fd.in]\n" +"\tsys.read\n" +"\tadd\tesp, byte 12\n" +"\tmov\tebx, eax\n" +"\tor\teax, eax\n" +"\tje\t.done\n" +"\tsub\teax, eax\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2594 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3900 +#, no-wrap +msgid "" +"align 4\n" +"write:\n" +"\tjecxz\t.ret\t; nothing to write\n" +"\tsub\tedi, ecx\t; start of buffer\n" +"\tpush\tecx\n" +"\tpush\tedi\n" +"\tpush\tdword [fd.out]\n" +"\tsys.write\n" +"\tadd\tesp, byte 12\n" +"\tsub\teax, eax\n" +"\tsub\tecx, ecx\t; buffer is empty now\n" +".ret:\n" +"\tret\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2599 +msgid "" +"Much of it is taken from [.filename]#hex.asm# above. But there is one " +"important difference: I no longer call `write` whenever I am outputting a " +"line feed. Yet, the code can be used interactively." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2603 +msgid "" +"I have found a better solution for the interactive problem since I first " +"started writing this chapter. I wanted to make sure each line is printed " +"out separately only when needed. After all, there is no need to flush out " +"every line when used non-interactively." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2607 +msgid "" +"The new solution I use now is to call `write` every time I find the input " +"buffer empty. That way, when running in the interactive mode, the program " +"reads one line from the user's keyboard, processes it, and sees its input " +"buffer is empty. It flushes its output and reads the next line." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2609 +#, no-wrap +msgid "The Dark Side of Buffering" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2613 +msgid "" +"This change prevents a mysterious lockup in a very specific case. I refer " +"to it as the _dark side of buffering_, mostly because it presents a danger " +"that is not quite obvious." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2617 +msgid "" +"It is unlikely to happen with a program like the csv above, so let us " +"consider yet another filter: In this case we expect our input to be raw data " +"representing color values, such as the _red_, _green_, and _blue_ " +"intensities of a pixel. Our output will be the negative of our input." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2620 +msgid "" +"Such a filter would be very simple to write. Most of it would look just " +"like all the other filters we have written so far, so I am only going to " +"show you its inner loop:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2628 +#, no-wrap +msgid "" +".loop:\n" +"\tcall\tgetchar\n" +"\tnot\tal\t\t; Create a negative\n" +"\tcall\tputchar\n" +"\tjmp\tshort .loop\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2631 +msgid "" +"Because this filter works with raw data, it is unlikely to be used " +"interactively." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2634 +msgid "" +"But it could be called by image manipulation software. And, unless it calls " +"`write` before each call to `read`, chances are it will lock up." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2636 +msgid "Here is what might happen:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2639 +msgid "The image editor will load our filter using the C function `popen()`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2640 +msgid "It will read the first row of pixels from a bitmap or pixmap." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2641 +msgid "" +"It will write the first row of pixels to the _pipe_ leading to the `fd.in` " +"of our filter." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2642 +msgid "" +"Our filter will read each pixel from its input, turn it to a negative, and " +"write it to its output buffer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2643 +msgid "Our filter will call `getchar` to fetch the next pixel." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2644 +msgid "`getchar` will find an empty input buffer, so it will call `read`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2645 +msgid "`read` will call the `SYS_read` system call." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2646 +msgid "" +"The _kernel_ will suspend our filter until the image editor sends more data " +"to the pipe." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2647 +msgid "" +"The image editor will read from the other pipe, connected to the `fd.out` of " +"our filter so it can set the first row of the output image _before_ it sends " +"us the second row of the input." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2648 +msgid "" +"The _kernel_ suspends the image editor until it receives some output from " +"our filter, so it can pass it on to the image editor." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2652 +msgid "" +"At this point our filter waits for the image editor to send it more data to " +"process, while the image editor is waiting for our filter to send it the " +"result of the processing of the first row. But the result sits in our " +"output buffer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2655 +msgid "" +"The filter and the image editor will continue waiting for each other forever " +"(or, at least, until they are killed). Our software has just entered a " +"crossref:secure[secure-race-conditions,race condition]." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2657 +msgid "" +"This problem does not exist if our filter flushes its output buffer _before_ " +"asking the _kernel_ for more input data." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2659 +#, no-wrap +msgid "Using the FPU" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2662 +msgid "" +"Strangely enough, most of assembly language literature does not even mention " +"the existence of the FPU, or _floating point unit_, let alone discuss " +"programming it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2664 +msgid "" +"Yet, never does assembly language shine more than when we create highly " +"optimized FPU code by doing things that can be done _only_ in assembly " +"language." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2666 +#, no-wrap +msgid "Organization of the FPU" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2670 +msgid "" +"The FPU consists of 8 80-bit floating-point registers. These are organized " +"in a stack fashion-you can `push` a value on TOS (_top of stack_) and you " +"can `pop` it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2672 +msgid "" +"That said, the assembly language op codes are not `push` and `pop` because " +"those are already taken." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2675 +msgid "" +"You can `push` a value on TOS by using `fld`, `fild`, and `fbld`. Several " +"other op codes let you `push` many common _constants_-such as _pi_-on the " +"TOS." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2678 +msgid "" +"Similarly, you can `pop` a value by using `fst`, `fstp`, `fist`, `fistp`, " +"and `fbstp`. Actually, only the op codes that end with a _p_ will literally " +"`pop` the value, the rest will `store` it somewhere else without removing it " +"from the TOS." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2680 +msgid "" +"We can transfer the data between the TOS and the computer memory either as a " +"32-bit, 64-bit, or 80-bit _real_, a 16-bit, 32-bit, or 64-bit _integer_, or " +"an 80-bit _packed decimal_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2683 +msgid "" +"The 80-bit _packed decimal_ is a special case of _binary coded decimal_ " +"which is very convenient when converting between the ASCII representation of " +"data and the internal data of the FPU. It allows us to use 18 significant " +"digits." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2685 +msgid "" +"No matter how we represent data in the memory, the FPU always stores it in " +"the 80-bit _real_ format in its registers." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2687 +msgid "" +"Its internal precision is at least 19 decimal digits, so even if we choose " +"to display results as ASCII in the full 18-digit precision, we are still " +"showing correct results." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2689 +msgid "" +"We can perform mathematical operations on the TOS: We can calculate its " +"_sine_, we can _scale_ it (i.e., we can multiply or divide it by a power of " +"2), we can calculate its base-2 _logarithm_, and many other things." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2691 +msgid "" +"We can also _multiply_ or _divide_ it by, _add_ it to, or _subtract_ it " +"from, any of the FPU registers (including itself)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2694 +msgid "" +"The official Intel op code for the TOS is `st`, and for the _registers_ " +"`st(0)`-`st(7)`. `st` and `st(0)`, then, refer to the same register." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2697 +msgid "" +"For whatever reasons, the original author of nasm has decided to use " +"different op codes, namely `st0`-`st7`. In other words, there are no " +"parentheses, and the TOS is always `st0`, never just `st`." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2699 +#, no-wrap +msgid "The Packed Decimal Format" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2703 +msgid "" +"The _packed decimal_ format uses 10 bytes (80 bits) of memory to represent " +"18 digits. The number represented there is always an _integer_." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2707 +msgid "" +"You can use it to get decimal places by multiplying the TOS by a power of 10 " +"first." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2711 +msgid "" +"The highest bit of the highest byte (byte 9) is the _sign bit_: If it is " +"set, the number is _negative_, otherwise, it is _positive_. The rest of the " +"bits of this byte are unused/ignored." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2713 +msgid "" +"The remaining 9 bytes store the 18 digits of the number: 2 digits per byte." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2715 +msgid "" +"The _more significant digit_ is stored in the high _nibble_ (4 bits), the " +"_less significant digit_ in the low _nibble_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2717 +msgid "" +"That said, you might think that `-1234567` would be stored in the memory " +"like this (using hexadecimal notation):" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2721 +#, no-wrap +msgid "80 00 00 00 00 00 01 23 45 67\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2724 +msgid "" +"Alas it is not! As with everything else of Intel make, even the _packed " +"decimal_ is _little-endian_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2726 +msgid "That means our `-1234567` is stored like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2730 +#, no-wrap +msgid "67 45 23 01 00 00 00 00 00 80\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2733 +msgid "Remember that, or you will be pulling your hair out in desperation!" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2739 +msgid "" +"The book to read-if you can find it-is Richard Startz' http://www.amazon.com/" +"exec/obidos/ASIN/013246604X/whizkidtechnomag[8087/80287/80387 for the IBM PC " +"& Compatibles]. Though it does seem to take the fact about the little-" +"endian storage of the _packed decimal_ for granted. I kid you not about the " +"desperation of trying to figure out what was wrong with the filter I show " +"below _before_ it occurred to me I should try the little-endian order even " +"for this type of data." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2742 +#, no-wrap +msgid "Excursion to Pinhole Photography" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2745 +msgid "" +"To write meaningful software, we must not only understand our programming " +"tools, but also the field we are creating software for." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2747 +msgid "" +"Our next filter will help us whenever we want to build a _pinhole camera_, " +"so, we need some background in _pinhole photography_ before we can continue." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2749 +#, no-wrap +msgid "The Camera" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2752 +msgid "" +"The easiest way to describe any camera ever built is as some empty space " +"enclosed in some lightproof material, with a small hole in the enclosure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2757 +msgid "" +"The enclosure is usually sturdy (e.g., a box), though sometimes it is " +"flexible (the bellows). It is quite dark inside the camera. However, the " +"hole lets light rays in through a single point (though in some cases there " +"may be several). These light rays form an image, a representation of " +"whatever is outside the camera, in front of the hole." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2759 +msgid "" +"If some light sensitive material (such as film) is placed inside the camera, " +"it can capture the image." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2761 +msgid "" +"The hole often contains a _lens_, or a lens assembly, often called the " +"_objective_." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2763 +#, no-wrap +msgid "The Pinhole" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2767 +msgid "" +"But, strictly speaking, the lens is not necessary: The original cameras did " +"not use a lens but a _pinhole_. Even today, _pinholes_ are used, both as a " +"tool to study how cameras work, and to achieve a special kind of image." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2771 +msgid "" +"The image produced by the _pinhole_ is all equally sharp. Or _blurred_. " +"There is an ideal size for a pinhole: If it is either larger or smaller, the " +"image loses its sharpness." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2773 +#, no-wrap +msgid "Focal Length" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2776 +msgid "" +"This ideal pinhole diameter is a function of the square root of _focal " +"length_, which is the distance of the pinhole from the film." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2780 +#, no-wrap +msgid "D = PC * sqrt(FL)\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2786 +msgid "" +"In here, `D` is the ideal diameter of the pinhole, `FL` is the focal length, " +"and `PC` is a pinhole constant. According to Jay Bender, its value is " +"`0.04`, while Kenneth Connors has determined it to be `0.037`. Others have " +"proposed other values. Plus, this value is for the daylight only: Other " +"types of light will require a different constant, whose value can only be " +"determined by experimentation." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2788 +#, no-wrap +msgid "The F-Number" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2792 +msgid "" +"The f-number is a very useful measure of how much light reaches the film. A " +"light meter can determine that, for example, to expose a film of specific " +"sensitivity with f5.6 mkay require the exposure to last 1/1000 sec." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2795 +msgid "" +"It does not matter whether it is a 35-mm camera, or a 6x9cm camera, etc. As " +"long as we know the f-number, we can determine the proper exposure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2797 +msgid "The f-number is easy to calculate:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2801 +#, no-wrap +msgid "F = FL / D\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2806 +msgid "" +"In other words, the f-number equals the focal length divided by the diameter " +"of the pinhole. It also means a higher f-number either implies a smaller " +"pinhole or a larger focal distance, or both. That, in turn, implies, the " +"higher the f-number, the longer the exposure has to be." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2809 +msgid "" +"Furthermore, while pinhole diameter and focal distance are one-dimensional " +"measurements, both, the film and the pinhole, are two-dimensional. That " +"means that if you have measured the exposure at f-number `A` as `t`, then " +"the exposure at f-number `B` is:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2813 +#, no-wrap +msgid "t * (B / A)²\n" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2816 +#, no-wrap +msgid "Normalized F-Number" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2819 +msgid "" +"While many modern cameras can change the diameter of their pinhole, and thus " +"their f-number, quite smoothly and gradually, such was not always the case." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2821 +msgid "" +"To allow for different f-numbers, cameras typically contained a metal plate " +"with several holes of different sizes drilled to them." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2824 +msgid "" +"Their sizes were chosen according to the above formula in such a way that " +"the resultant f-number was one of standard f-numbers used on all cameras " +"everywhere. For example, a very old Kodak Duaflex IV camera in my " +"possession has three such holes for f-numbers 8, 11, and 16." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2827 +msgid "" +"A more recently made camera may offer f-numbers of 2.8, 4, 5.6, 8, 11, 16, " +"22, and 32 (as well as others). These numbers were not chosen arbitrarily: " +"They all are powers of the square root of 2, though they may be rounded " +"somewha." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2829 +#, no-wrap +msgid "The F-Stop" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2833 +msgid "" +"A typical camera is designed in such a way that setting any of the " +"normalized f-numbers changes the feel of the dial. It will naturally _stop_ " +"in that position. Because of that, these positions of the dial are called f-" +"stops." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2837 +msgid "" +"Since the f-numbers at each stop are powers of the square root of 2, moving " +"the dial by 1 stop will double the amount of light required for proper " +"exposure. Moving it by 2 stops will quadruple the required exposure. " +"Moving the dial by 3 stops will require the increase in exposure 8 times, " +"etc." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2839 +#, no-wrap +msgid "Designing the Pinhole Software" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2842 +msgid "" +"We are now ready to decide what exactly we want our pinhole software to do." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2844 +#, no-wrap +msgid "Processing Program Input" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2848 +msgid "" +"Since its main purpose is to help us design a working pinhole camera, we " +"will use the _focal length_ as the input to the program. This is something " +"we can determine without software: Proper focal length is determined by the " +"size of the film and by the need to shoot \"regular\" pictures, wide angle " +"pictures, or telephoto pictures." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2850 +msgid "" +"Most of the programs we have written so far worked with individual " +"characters, or bytes, as their input: The hex program converted individual " +"bytes into a hexadecimal number, the csv program either let a character " +"through, or deleted it, or changed it to a different character, etc." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2852 +msgid "" +"One program, ftuc used the state machine to consider at most two input bytes " +"at a time." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2854 +msgid "" +"But our pinhole program cannot just work with individual characters, it has " +"to deal with larger syntactic units." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2856 +msgid "" +"For example, if we want the program to calculate the pinhole diameter (and " +"other values we will discuss later) at the focal lengths of `100 mm`, `150 " +"mm`, and `210 mm`, we may want to enter something like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2860 +#, no-wrap +msgid " 100, 150, 210\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2865 +msgid "" +"Our program needs to consider more than a single byte of input at a time. " +"When it sees the first `1`, it must understand it is seeing the first digit " +"of a decimal number. When it sees the `0` and the other `0`, it must know " +"it is seeing more digits of the same number." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2870 +msgid "" +"When it encounters the first comma, it must know it is no longer receiving " +"the digits of the first number. It must be able to convert the digits of " +"the first number into the value of `100`. And the digits of the second " +"number into the value of `150`. And, of course, the digits of the third " +"number into the numeric value of `210`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2872 +msgid "" +"We need to decide what delimiters to accept: Do the input numbers have to be " +"separated by a comma? If so, how do we treat two numbers separated by " +"something else?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2877 +msgid "" +"Personally, I like to keep it simple. Something either is a number, so I " +"process it. Or it is not a number, so I discard it. I do not like the " +"computer complaining about me typing in an extra character when it is " +"_obvious_ that it is an extra character. Duh!" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2879 +msgid "" +"Plus, it allows me to break up the monotony of computing and type in a query " +"instead of just a number:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2884 +#, no-wrap +msgid "" +"What is the best pinhole diameter for the\n" +"\t focal length of 150?\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2887 +msgid "There is no reason for the computer to spit out a number of complaints:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2894 +#, no-wrap +msgid "" +"Syntax error: What\n" +"Syntax error: is\n" +"Syntax error: the\n" +"Syntax error: best\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2897 +msgid "Et cetera, et cetera, et cetera." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2900 +msgid "" +"Secondly, I like the `+#+` character to denote the start of a comment which " +"extends to the end of the line. This does not take too much effort to code, " +"and lets me treat input files for my software as executable scripts." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2902 +msgid "" +"In our case, we also need to decide what units the input should come in: We " +"choose _millimeters_ because that is how most photographers measure the " +"focus length." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2904 +msgid "" +"Finally, we need to decide whether to allow the use of the decimal point (in " +"which case we must also consider the fact that much of the world uses a " +"decimal _comma_)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2908 +msgid "" +"In our case allowing for the decimal point/comma would offer a false sense " +"of precision: There is little if any noticeable difference between the focus " +"lengths of `50` and `51`, so allowing the user to input something like " +"`50.5` is not a good idea. This is my opinion, mind you, but I am the one " +"writing this program. You can make other choices in yours, of course." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2910 +#, no-wrap +msgid "Offering Options" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2915 +msgid "" +"The most important thing we need to know when building a pinhole camera is " +"the diameter of the pinhole. Since we want to shoot sharp images, we will " +"use the above formula to calculate the pinhole diameter from focal length. " +"As experts are offering several different values for the `PC` constant, we " +"will need to have the choice." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2917 +msgid "" +"It is traditional in UNIX(R) programming to have two main ways of choosing " +"program parameters, plus to have a default for the time the user does not " +"make a choice." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2919 +msgid "Why have two ways of choosing?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2921 +msgid "" +"One is to allow a (relatively) _permanent_ choice that applies automatically " +"each time the software is run without us having to tell it over and over " +"what we want it to do." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2926 +msgid "" +"The permanent choices may be stored in a configuration file, typically found " +"in the user's home directory. The file usually has the same name as the " +"application but is started with a dot. Often _\"rc\"_ is added to the file " +"name. So, ours could be [.filename]#~/.pinhole# or [.filename]#~/." +"pinholerc#. (The [.filename]#~/# means current user's home directory.)" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2931 +msgid "" +"The configuration file is used mostly by programs that have many " +"configurable parameters. Those that have only one (or a few) often use a " +"different method: They expect to find the parameter in an _environment " +"variable_. In our case, we might look at an environment variable named " +"`PINHOLE`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2934 +msgid "" +"Usually, a program uses one or the other of the above methods. Otherwise, " +"if a configuration file said one thing, but an environment variable another, " +"the program might get confused (or just too complicated)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2936 +msgid "" +"Because we only need to choose _one_ such parameter, we will go with the " +"second method and search the environment for a variable named `PINHOLE`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2939 +msgid "" +"The other way allows us to make _ad hoc_ decisions: _\"Though I usually want " +"you to use 0.039, this time I want 0.03872.\"_ In other words, it allows us " +"to _override_ the permanent choice." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2941 +msgid "This type of choice is usually done with command line parameters." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2949 +msgid "" +"Finally, a program _always_ needs a _default_. The user may not make any " +"choices. Perhaps he does not know what to choose. Perhaps he is \"just " +"browsing.\" Preferably, the default will be the value most users would " +"choose anyway. That way they do not need to choose. Or, rather, they can " +"choose the default without an additional effort." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2951 +msgid "" +"Given this system, the program may find conflicting options, and handle them " +"this way:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2954 +msgid "" +"If it finds an _ad hoc_ choice (e.g., command line parameter), it should " +"accept that choice. It must ignore any permanent choice and any default." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2955 +msgid "" +"_Otherwise_, if it finds a permanent option (e.g., an environment variable), " +"it should accept it, and ignore the default." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2956 +msgid "_Otherwise_, it should use the default." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2958 +msgid "We also need to decide what _format_ our `PC` option should have." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2960 +msgid "" +"At first site, it seems obvious to use the `PINHOLE=0.04` format for the " +"environment variable, and `-p0.04` for the command line." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2964 +msgid "" +"Allowing that is actually a security risk. The `PC` constant is a very small " +"number. Naturally, we will test our software using various small values of " +"`PC`. But what will happen if someone runs the program choosing a huge " +"value?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2966 +msgid "" +"It may crash the program because we have not designed it to handle huge " +"numbers." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2969 +msgid "" +"Or, we may spend more time on the program so it can handle huge numbers. We " +"might do that if we were writing commercial software for computer illiterate " +"audience." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2971 +msgid "Or, we might say, _\"Tough! The user should know better.\"\"_" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2974 +msgid "" +"Or, we just may make it impossible for the user to enter a huge number. " +"This is the approach we will take: We will use an _implied 0._ prefix." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2977 +msgid "" +"In other words, if the user wants `0.04`, we will expect him to type `-p04`, " +"or set `PINHOLE=04` in his environment. So, if he says `-p9999999`, we will " +"interpret it as ``0.9999999``-still ridiculous but at least safer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2980 +msgid "" +"Secondly, many users will just want to go with either Bender's constant or " +"Connors' constant. To make it easier on them, we will interpret `-b` as " +"identical to `-p04`, and `-c` as identical to `-p037`." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2982 +#, no-wrap +msgid "The Output" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2985 +msgid "" +"We need to decide what we want our software to send to the output, and in " +"what format." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2987 +msgid "" +"Since our input allows for an unspecified number of focal length entries, it " +"makes sense to use a traditional database-style output of showing the result " +"of the calculation for each focal length on a separate line, while " +"separating all values on one line by a `tab` character." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2990 +msgid "" +"Optionally, we should also allow the user to specify the use of the CSV " +"format we have studied earlier. In this case, we will print out a line of " +"comma-separated names describing each field of every line, then show our " +"results as before, but substituting a `comma` for the `tab`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2995 +msgid "" +"We need a command line option for the CSV format. We cannot use `-c` " +"because that already means _use Connors' constant_. For some strange " +"reason, many web sites refer to CSV files as _\"Excel spreadsheet\"_ (though " +"the CSV format predates Excel). We will, therefore, use the `-e` switch to " +"inform our software we want the output in the CSV format." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:2999 +msgid "" +"We will start each line of the output with the focal length. This may sound " +"repetitious at first, especially in the interactive mode: The user types in " +"the focal length, and we are repeating it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3003 +msgid "" +"But the user can type several focal lengths on one line. The input can also " +"come in from a file or from the output of another program. In that case the " +"user does not see the input at all." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3005 +msgid "" +"By the same token, the output can go to a file which we will want to examine " +"later, or it could go to the printer, or become the input of another program." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3007 +msgid "" +"So, it makes perfect sense to start each line with the focal length as " +"entered by the user." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3010 +msgid "" +"No, wait! Not as entered by the user. What if the user types in something " +"like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3014 +#, no-wrap +msgid " 00000000150\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3017 +msgid "Clearly, we need to strip those leading zeros." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3019 +msgid "" +"So, we might consider reading the user input as is, converting it to binary " +"inside the FPU, and printing it out from there." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3021 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3206 +msgid "But..." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3023 +msgid "What if the user types something like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3027 +#, no-wrap +msgid " 17459765723452353453534535353530530534563507309676764423\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3032 +msgid "" +"Ha! The packed decimal FPU format lets us input 18-digit numbers. But the " +"user has entered more than 18 digits. How do we handle that?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3034 +msgid "" +"Well, we _could_ modify our code to read the first 18 digits, enter it to " +"the FPU, then read more, multiply what we already have on the TOS by 10 " +"raised to the number of additional digits, then `add` to it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3038 +msgid "" +"Yes, we could do that. But in _this_ program it would be ridiculous (in a " +"different one it may be just the thing to do): Even the circumference of the " +"Earth expressed in millimeters only takes 11 digits. Clearly, we cannot " +"build a camera that large (not yet, anyway)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3040 +msgid "" +"So, if the user enters such a huge number, he is either bored, or testing " +"us, or trying to break into the system, or playing games-doing anything but " +"designing a pinhole camera." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3042 +msgid "What will we do?" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3044 +msgid "We will slap him in the face, in a manner of speaking:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3048 +#, no-wrap +msgid "17459765723452353453534535353530530534563507309676764423\t???\t???\t???\t???\t???\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3052 +msgid "" +"To achieve that, we will simply ignore any leading zeros. Once we find a " +"non-zero digit, we will initialize a counter to `0` and start taking three " +"steps:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3055 +msgid "Send the digit to the output." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3056 +msgid "" +"Append the digit to a buffer we will use later to produce the packed decimal " +"we can send to the FPU." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3057 +msgid "Increase the counter." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3059 +msgid "" +"Now, while we are taking these three steps, we also need to watch out for " +"one of two conditions:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3061 +msgid "" +"If the counter grows above 18, we stop appending to the buffer. We continue " +"reading the digits and sending them to the output." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3062 +msgid "" +"If, or rather _when_, the next input character is not a digit, we are done " +"inputting for now." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3065 +msgid "" +"Incidentally, we can simply discard the non-digit, unless it is a `+#+`, " +"which we must return to the input stream. It starts a comment, so we must " +"see it after we are done producing output and start looking for more input." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3067 +msgid "" +"That still leaves one possibility uncovered: If all the user enters is a " +"zero (or several zeros), we will never find a non-zero to display." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3070 +msgid "" +"We can determine this has happened whenever our counter stays at `0`. In " +"that case we need to send `0` to the output, and perform another \"slap in " +"the face\":" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3074 +#, no-wrap +msgid "0\t???\t???\t???\t???\t???\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3077 +msgid "" +"Once we have displayed the focal length and determined it is valid (greater " +"than `0` but not exceeding 18 digits), we can calculate the pinhole diameter." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3080 +msgid "" +"It is not by coincidence that _pinhole_ contains the word _pin_. Indeed, " +"many a pinhole literally is a _pin hole_, a hole carefully punched with the " +"tip of a pin." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3083 +msgid "" +"That is because a typical pinhole is very small. Our formula gets the result " +"in millimeters. We will multiply it by `1000`, so we can output the result " +"in _microns_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3085 +msgid "At this point we have yet another trap to face: _Too much precision._" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3089 +msgid "" +"Yes, the FPU was designed for high precision mathematics. But we are not " +"dealing with high precision mathematics. We are dealing with physics " +"(optics, specifically)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3093 +msgid "" +"Suppose we want to convert a truck into a pinhole camera (we would not be " +"the first ones to do that!). Suppose its box is `12` meters long, so we " +"have the focal length of `12000`. Well, using Bender's constant, it gives " +"us square root of `12000` multiplied by `0.04`, which is `4.381780460` " +"millimeters, or `4381.780460` microns." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3098 +msgid "" +"Put either way, the result is absurdly precise. Our truck is not _exactly_ " +"`12000` millimeters long. We did not measure its length with such a " +"precision, so stating we need a pinhole with the diameter of `4.381780460` " +"millimeters is, well, deceiving. `4.4` millimeters would do just fine." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3103 +msgid "" +"I \"only\" used ten digits in the above example. Imagine the absurdity of " +"going for all 18!" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3109 +msgid "" +"We need to limit the number of significant digits of our result. One way of " +"doing it is by using an integer representing microns. So, our truck would " +"need a pinhole with the diameter of `4382` microns. Looking at that number, " +"we still decide that `4400` microns, or `4.4` millimeters is close enough." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3112 +msgid "" +"Additionally, we can decide that no matter how big a result we get, we only " +"want to display four significant digits (or any other number of them, of " +"course). Alas, the FPU does not offer rounding to a specific number of " +"digits (after all, it does not view the numbers as decimal but as binary)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3114 +msgid "" +"We, therefore, must devise an algorithm to reduce the number of significant " +"digits." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3116 +msgid "" +"Here is mine (I think it is awkward-if you know a better one, _please_, let " +"me know):" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3119 +msgid "Initialize a counter to `0`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3120 +msgid "" +"While the number is greater than or equal to `10000`, divide it by `10` and " +"increase the counter." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3121 +msgid "Output the result." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3122 +msgid "" +"While the counter is greater than `0`, output `0` and decrease the counter." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3127 +msgid "" +"The `10000` is only good if you want _four_ significant digits. For any " +"other number of significant digits, replace `10000` with `10` raised to the " +"number of significant digits." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3130 +msgid "" +"We will, then, output the pinhole diameter in microns, rounded off to four " +"significant digits." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3133 +msgid "" +"At this point, we know the _focal length_ and the _pinhole diameter_. That " +"means we have enough information to also calculate the _f-number_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3137 +msgid "" +"We will display the f-number, rounded to four significant digits. Chances " +"are the f-number will tell us very little. To make it more meaningful, we " +"can find the nearest _normalized f-number_, i.e., the nearest power of the " +"square root of 2." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3143 +msgid "" +"We do that by multiplying the actual f-number by itself, which, of course, " +"will give us its `square`. We will then calculate its base-2 logarithm, " +"which is much easier to do than calculating the base-square-root-of-2 " +"logarithm! We will round the result to the nearest integer. Next, we will " +"raise 2 to the result. Actually, the FPU gives us a good shortcut to do " +"that: We can use the `fscale` op code to \"scale\" 1, which is analogous to " +"``shift``ing an integer left. Finally, we calculate the square root of it " +"all, and we have the nearest normalized f-number." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3146 +msgid "" +"If all that sounds overwhelming-or too much work, perhaps-it may become much " +"clearer if you see the code. It takes 9 op codes altogether:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3158 +#, no-wrap +msgid "" +"fmul\tst0, st0\n" +"\tfld1\n" +"\tfld\tst1\n" +"\tfyl2x\n" +"\tfrndint\n" +"\tfld1\n" +"\tfscale\n" +"\tfsqrt\n" +"\tfstp\tst1\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3162 +msgid "" +"The first line, `fmul st0, st0`, squares the contents of the TOS (top of the " +"stack, same as `st`, called `st0` by nasm). The `fld1` pushes `1` on the " +"TOS." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3166 +msgid "" +"The next line, `fld st1`, pushes the square back to the TOS. At this point " +"the square is both in `st` and `st(2)` (it will become clear why we leave a " +"second copy on the stack in a moment). `st(1)` contains `1`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3169 +msgid "" +"Next, `fyl2x` calculates base-2 logarithm of `st` multiplied by `st(1)`. " +"That is why we placed `1` on `st(1)` before." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3171 +msgid "" +"At this point, `st` contains the logarithm we have just calculated, `st(1)` " +"contains the square of the actual f-number we saved for later." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3175 +msgid "" +"`frndint` rounds the TOS to the nearest integer. `fld1` pushes a `1`. " +"`fscale` shifts the `1` we have on the TOS by the value in `st(1)`, " +"effectively raising 2 to `st(1)`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3177 +msgid "" +"Finally, `fsqrt` calculates the square root of the result, i.e., the nearest " +"normalized f-number." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3180 +msgid "" +"We now have the nearest normalized f-number on the TOS, the base-2 logarithm " +"rounded to the nearest integer in `st(1)`, and the square of the actual f-" +"number in `st(2)`. We are saving the value in `st(2)` for later." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3186 +msgid "" +"But we do not need the contents of `st(1)` anymore. The last line, `fstp " +"st1`, places the contents of `st` to `st(1)`, and pops. As a result, what " +"was `st(1)` is now `st`, what was `st(2)` is now `st(1)`, etc. The new `st` " +"contains the normalized f-number. The new `st(1)` contains the square of " +"the actual f-number we have stored there for posterity." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3189 +msgid "" +"At this point, we are ready to output the normalized f-number. Because it " +"is normalized, we will not round it off to four significant digits, but will " +"send it out in its full precision." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3192 +msgid "" +"The normalized f-number is useful as long as it is reasonably small and can " +"be found on our light meter. Otherwise we need a different method of " +"determining proper exposure." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3194 +msgid "" +"Earlier we have figured out the formula of calculating proper exposure at an " +"arbitrary f-number from that measured at a different f-number." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3197 +msgid "" +"Every light meter I have ever seen can determine proper exposure at f5.6. " +"We will, therefore, calculate an _\"f5.6 multiplier,\"_ i.e., by how much we " +"need to multiply the exposure measured at f5.6 to determine the proper " +"exposure for our pinhole camera." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3199 +msgid "" +"From the above formula we know this factor can be calculated by dividing our " +"f-number (the actual one, not the normalized one) by `5.6`, and squaring the " +"result." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3201 +msgid "" +"Mathematically, dividing the square of our f-number by the square of `5.6` " +"will give us the same result." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3204 +msgid "" +"Computationally, we do not want to square two numbers when we can only " +"square one. So, the first solution seems better at first." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3212 +msgid "" +"`5.6` is a _constant_. We do not have to have our FPU waste precious " +"cycles. We can just tell it to divide the square of the f-number by " +"whatever `5.6²` equals to. Or we can divide the f-number by `5.6`, and then " +"square the result. The two ways now seem equal." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3214 +msgid "But, they are not!" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3218 +msgid "" +"Having studied the principles of photography above, we remember that the " +"`5.6` is actually square root of 2 raised to the fifth power. An " +"_irrational_ number. The square of this number is _exactly_ `32`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3224 +msgid "" +"Not only is `32` an integer, it is a power of 2. We do not need to divide " +"the square of the f-number by `32`. We only need to use `fscale` to shift " +"it right by five positions. In the FPU lingo it means we will `fscale` it " +"with `st(1)` equal to `-5`. That is _much faster_ than a division." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3227 +msgid "" +"So, now it has become clear why we have saved the square of the f-number on " +"the top of the FPU stack. The calculation of the f5.6 multiplier is the " +"easiest calculation of this entire program! We will output it rounded to " +"four significant digits." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3230 +msgid "" +"There is one more useful number we can calculate: The number of stops our f-" +"number is from f5.6. This may help us if our f-number is just outside the " +"range of our light meter, but we have a shutter which lets us set various " +"speeds, and this shutter uses stops." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3233 +msgid "" +"Say, our f-number is 5 stops from f5.6, and the light meter says we should " +"use 1/1000 sec. Then we can set our shutter speed to 1/1000 first, then " +"move the dial by 5 stops." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3238 +msgid "" +"This calculation is quite easy as well. All we have to do is to calculate " +"the base-2 logarithm of the f5.6 multiplier we had just calculated (though " +"we need its value from before we rounded it off). We then output the result " +"rounded to the nearest integer. We do not need to worry about having more " +"than four significant digits in this one: The result is most likely to have " +"only one or two digits anyway." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3240 +#, no-wrap +msgid "FPU Optimizations" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3243 +msgid "" +"In assembly language we can optimize the FPU code in ways impossible in high " +"languages, including C." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3247 +msgid "" +"Whenever a C function needs to calculate a floating-point value, it loads " +"all necessary variables and constants into FPU registers. It then does " +"whatever calculation is required to get the correct result. Good C " +"compilers can optimize that part of the code really well." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3251 +msgid "" +"It \"returns\" the value by leaving the result on the TOS. However, before " +"it returns, it cleans up. Any variables and constants it used in its " +"calculation are now gone from the FPU." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3253 +msgid "" +"It cannot do what we just did above: We calculated the square of the f-" +"number and kept it on the stack for later use by another function." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3256 +msgid "" +"We _knew_ we would need that value later on. We also knew we had enough " +"room on the stack (which only has room for 8 numbers) to store it there." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3258 +msgid "" +"A C compiler has no way of knowing that a value it has on the stack will be " +"required again in the very near future." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3261 +msgid "" +"Of course, the C programmer may know it. But the only recourse he has is to " +"store the value in a memory variable." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3263 +msgid "" +"That means, for one, the value will be changed from the 80-bit precision " +"used internally by the FPU to a C _double_ (64 bits) or even _single_ (32 " +"bits)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3266 +msgid "" +"That also means that the value must be moved from the TOS into the memory, " +"and then back again. Alas, of all FPU operations, the ones that access the " +"computer memory are the slowest." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3268 +msgid "" +"So, whenever programming the FPU in assembly language, look for the ways of " +"keeping intermediate results on the FPU stack." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3270 +msgid "" +"We can take that idea even further! In our program we are using a _constant_ " +"(the one we named `PC`)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3273 +msgid "" +"It does not matter how many pinhole diameters we are calculating: 1, 10, 20, " +"1000, we are always using the same constant. Therefore, we can optimize our " +"program by keeping the constant on the stack all the time." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3276 +msgid "" +"Early on in our program, we are calculating the value of the above " +"constant. We need to divide our input by `10` for every digit in the " +"constant." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3279 +msgid "" +"It is much faster to multiply than to divide. So, at the start of our " +"program, we divide `10` into `1` to obtain `0.1`, which we then keep on the " +"stack: Instead of dividing the input by `10` for every digit, we multiply it " +"by `0.1`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3283 +msgid "" +"By the way, we do not input `0.1` directly, even though we could. We have a " +"reason for that: While `0.1` can be expressed with just one decimal place, " +"we do not know how many _binary_ places it takes. We, therefore, let the " +"FPU calculate its binary value to its own high precision." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3288 +msgid "" +"We are using other constants: We multiply the pinhole diameter by `1000` to " +"convert it from millimeters to microns. We compare numbers to `10000` when " +"we are rounding them off to four significant digits. So, we keep both, " +"`1000` and `10000`, on the stack. And, of course, we reuse the `0.1` when " +"rounding off numbers to four digits." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3294 +msgid "" +"Last but not least, we keep `-5` on the stack. We need it to scale the " +"square of the f-number, instead of dividing it by `32`. It is not by " +"coincidence we load this constant last. That makes it the top of the stack " +"when only the constants are on it. So, when the square of the f-number is " +"being scaled, the `-5` is at `st(1)`, precisely where `fscale` expects it to " +"be." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3297 +msgid "" +"It is common to create certain constants from scratch instead of loading " +"them from the memory. That is what we are doing with `-5`:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3306 +#, no-wrap +msgid "" +"\tfld1\t\t\t; TOS = 1\n" +"\tfadd\tst0, st0\t; TOS = 2\n" +"\tfadd\tst0, st0\t; TOS = 4\n" +"\tfld1\t\t\t; TOS = 1\n" +"\tfaddp\tst1, st0\t; TOS = 5\n" +"\tfchs\t\t\t; TOS = -5\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3309 +msgid "" +"We can generalize all these optimizations into one rule: _Keep repeat values " +"on the stack!_" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3314 +msgid "" +"_PostScript(R)_ is a stack-oriented programming language. There are many " +"more books available about PostScript(R) than about the FPU assembly " +"language: Mastering PostScript(R) will help you master the FPU." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3317 +#, no-wrap +msgid "pinhole-The Code" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3332 +#, no-wrap +msgid "" +";;;;;;; pinhole.asm ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n" +";\n" +"; Find various parameters of a pinhole camera construction and use\n" +";\n" +"; Started:\t 9-Jun-2001\n" +"; Updated:\t10-Jun-2001\n" +";\n" +"; Copyright (c) 2001 G. Adam Stanislav\n" +"; All rights reserved.\n" +";\n" +";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3367 +#, no-wrap +msgid "" +"section\t.data\n" +"align 4\n" +"ten\tdd\t10\n" +"thousand\tdd\t1000\n" +"tthou\tdd\t10000\n" +"fd.in\tdd\tstdin\n" +"fd.out\tdd\tstdout\n" +"envar\tdb\t'PINHOLE='\t; Exactly 8 bytes, or 2 dwords long\n" +"pinhole\tdb\t'04,', \t\t; Bender's constant (0.04)\n" +"connors\tdb\t'037', 0Ah\t; Connors' constant\n" +"usg\tdb\t'Usage: pinhole [-b] [-c] [-e] [-p <value>] [-o <outfile>] [-i <infile>]', 0Ah\n" +"usglen\tequ\t$-usg\n" +"iemsg\tdb\t\"pinhole: Can't open input file\", 0Ah\n" +"iemlen\tequ\t$-iemsg\n" +"oemsg\tdb\t\"pinhole: Can't create output file\", 0Ah\n" +"oemlen\tequ\t$-oemsg\n" +"pinmsg\tdb\t\"pinhole: The PINHOLE constant must not be 0\", 0Ah\n" +"pinlen\tequ\t$-pinmsg\n" +"toobig\tdb\t\"pinhole: The PINHOLE constant may not exceed 18 decimal places\", 0Ah\n" +"biglen\tequ\t$-toobig\n" +"huhmsg\tdb\t9, '???'\n" +"separ\tdb\t9, '???'\n" +"sep2\tdb\t9, '???'\n" +"sep3\tdb\t9, '???'\n" +"sep4\tdb\t9, '???', 0Ah\n" +"huhlen\tequ\t$-huhmsg\n" +"header\tdb\t'focal length in millimeters,pinhole diameter in microns,'\n" +"\tdb\t'F-number,normalized F-number,F-5.6 multiplier,stops '\n" +"\tdb\t'from F-5.6', 0Ah\n" +"headlen\tequ\t$-header\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3373 +#, no-wrap +msgid "" +"section .bss\n" +"ibuffer\tresb\tBUFSIZE\n" +"obuffer\tresb\tBUFSIZE\n" +"dbuffer\tresb\t20\t\t; decimal input buffer\n" +"bbuffer\tresb\t10\t\t; BCD buffer\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3384 +#, no-wrap +msgid "" +"section\t.text\n" +"align 4\n" +"huh:\n" +"\tcall\twrite\n" +"\tpush\tdword huhlen\n" +"\tpush\tdword huhmsg\n" +"\tpush\tdword [fd.out]\n" +"\tsys.write\n" +"\tadd\tesp, byte 12\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3393 +#, no-wrap +msgid "" +"align 4\n" +"perr:\n" +"\tpush\tdword pinlen\n" +"\tpush\tdword pinmsg\n" +"\tpush\tdword stderr\n" +"\tsys.write\n" +"\tpush\tdword 4\t\t; return failure\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3402 +#, no-wrap +msgid "" +"align 4\n" +"consttoobig:\n" +"\tpush\tdword biglen\n" +"\tpush\tdword toobig\n" +"\tpush\tdword stderr\n" +"\tsys.write\n" +"\tpush\tdword 5\t\t; return failure\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3411 +#, no-wrap +msgid "" +"align 4\n" +"ierr:\n" +"\tpush\tdword iemlen\n" +"\tpush\tdword iemsg\n" +"\tpush\tdword stderr\n" +"\tsys.write\n" +"\tpush\tdword 1\t\t; return failure\n" +"\tsys.exit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3435 +#, no-wrap +msgid "" +"align 4\n" +"global\t_start\n" +"_start:\n" +"\tadd\tesp, byte 8\t; discard argc and argv[0]\n" +"\tsub\tesi, esi\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3440 +#, no-wrap +msgid "" +".arg:\n" +"\tpop\tecx\n" +"\tor\tecx, ecx\n" +"\tje\tnear .getenv\t\t; no more arguments\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3448 +#, no-wrap +msgid "" +"\tinc\tecx\n" +"\tmov\tax, [ecx]\n" +"\tinc\tecx\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3466 +#, no-wrap +msgid "" +"\tor\tah, ah\n" +"\tjne\t.openoutput\n" +"\tpop\tecx\n" +"\tjecxz\tusage\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3493 +#, no-wrap +msgid "" +"\t; Find the path to the input file\n" +"\tor\tah, ah\n" +"\tjne\t.openinput\n" +"\tpop\tecx\n" +"\tor\tecx, ecx\n" +"\tje near usage\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3509 +#, no-wrap +msgid "" +".p:\n" +"\tcmp\tal, 'p'\n" +"\tjne\t.c\n" +"\tor\tah, ah\n" +"\tjne\t.pcheck\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3513 +#, no-wrap +msgid "" +"\tpop\tecx\n" +"\tor\tecx, ecx\n" +"\tje\tnear usage\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3515 +#, no-wrap +msgid "\tmov\tah, [ecx]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3523 +#, no-wrap +msgid "" +".pcheck:\n" +"\tcmp\tah, '0'\n" +"\tjl\tnear usage\n" +"\tcmp\tah, '9'\n" +"\tja\tnear usage\n" +"\tmov\tesi, ecx\n" +"\tjmp\t.arg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3531 +#, no-wrap +msgid "" +".c:\n" +"\tcmp\tal, 'c'\n" +"\tjne\t.b\n" +"\tor\tah, ah\n" +"\tjne\tnear usage\n" +"\tmov\tesi, connors\n" +"\tjmp\t.arg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3539 +#, no-wrap +msgid "" +".b:\n" +"\tcmp\tal, 'b'\n" +"\tjne\t.e\n" +"\tor\tah, ah\n" +"\tjne\tnear usage\n" +"\tmov\tesi, pinhole\n" +"\tjmp\t.arg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3552 +#, no-wrap +msgid "" +".e:\n" +"\tcmp\tal, 'e'\n" +"\tjne\tnear usage\n" +"\tor\tah, ah\n" +"\tjne\tnear usage\n" +"\tmov\tal, ','\n" +"\tmov\t[huhmsg], al\n" +"\tmov\t[separ], al\n" +"\tmov\t[sep2], al\n" +"\tmov\t[sep3], al\n" +"\tmov\t[sep4], al\n" +"\tjmp\t.arg\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3559 +#, no-wrap +msgid "" +"align 4\n" +".getenv:\n" +"\t; If ESI = 0, we did not have a -p argument,\n" +"\t; and need to check the environment for \"PINHOLE=\"\n" +"\tor\tesi, esi\n" +"\tjne\t.init\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3561 +#, no-wrap +msgid "\tsub\tecx, ecx\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3566 +#, no-wrap +msgid "" +".nextenv:\n" +"\tpop\tesi\n" +"\tor\tesi, esi\n" +"\tje\t.default\t; no PINHOLE envar found\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3572 +#, no-wrap +msgid "" +"\t; check if this envar starts with 'PINHOLE='\n" +"\tmov\tedi, envar\n" +"\tmov\tcl, 2\t\t; 'PINHOLE=' is 2 dwords long\n" +"rep\tcmpsd\n" +"\tjne\t.nextenv\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3580 +#, no-wrap +msgid "" +"\t; Check if it is followed by a digit\n" +"\tmov\tal, [esi]\n" +"\tcmp\tal, '0'\n" +"\tjl\t.default\n" +"\tcmp\tal, '9'\n" +"\tjbe\t.init\n" +"\t; fall through\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3587 +#, no-wrap +msgid "" +"align 4\n" +".default:\n" +"\t; We got here because we had no -p argument,\n" +"\t; and did not find the PINHOLE envar.\n" +"\tmov\tesi, pinhole\n" +"\t; fall through\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3596 +#, no-wrap +msgid "" +"align 4\n" +".init:\n" +"\tsub\teax, eax\n" +"\tsub\tebx, ebx\n" +"\tsub\tecx, ecx\n" +"\tsub\tedx, edx\n" +"\tmov\tedi, dbuffer+1\n" +"\tmov\tbyte [dbuffer], '0'\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3605 +#, no-wrap +msgid "" +"\t; Convert the pinhole constant to real\n" +".constloop:\n" +"\tlodsb\n" +"\tcmp\tal, '9'\n" +"\tja\t.setconst\n" +"\tcmp\tal, '0'\n" +"\tje\t.processconst\n" +"\tjb\t.setconst\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3607 +#, no-wrap +msgid "\tinc\tdl\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3614 +#, no-wrap +msgid "" +".processconst:\n" +"\tinc\tcl\n" +"\tcmp\tcl, 18\n" +"\tja\tnear consttoobig\n" +"\tstosb\n" +"\tjmp\tshort .constloop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3619 +#, no-wrap +msgid "" +"align 4\n" +".setconst:\n" +"\tor\tdl, dl\n" +"\tje\tnear perr\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3622 +#, no-wrap +msgid "" +"\tfinit\n" +"\tfild\tdword [tthou]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3626 +#, no-wrap +msgid "" +"\tfld1\n" +"\tfild\tdword [ten]\n" +"\tfdivp\tst1, st0\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3629 +#, no-wrap +msgid "" +"\tfild\tdword [thousand]\n" +"\tmov\tedi, obuffer\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3632 +#, no-wrap +msgid "" +"\tmov\tebp, ecx\n" +"\tcall\tbcdload\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3636 +#, no-wrap +msgid "" +".constdiv:\n" +"\tfmul\tst0, st2\n" +"\tloop\t.constdiv\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3643 +#, no-wrap +msgid "" +"\tfld1\n" +"\tfadd\tst0, st0\n" +"\tfadd\tst0, st0\n" +"\tfld1\n" +"\tfaddp\tst1, st0\n" +"\tfchs\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3648 +#, no-wrap +msgid "" +"\t; If we are creating a CSV file,\n" +"\t; print header\n" +"\tcmp\tbyte [separ], ','\n" +"\tjne\t.bigloop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3653 +#, no-wrap +msgid "" +"\tpush\tdword headlen\n" +"\tpush\tdword header\n" +"\tpush\tdword [fd.out]\n" +"\tsys.write\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3657 +#, no-wrap +msgid "" +".bigloop:\n" +"\tcall\tgetchar\n" +"\tjc\tnear done\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3663 +#, no-wrap +msgid "" +"\t; Skip to the end of the line if you got '#'\n" +"\tcmp\tal, '#'\n" +"\tjne\t.num\n" +"\tcall\tskiptoeol\n" +"\tjmp\tshort .bigloop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3670 +#, no-wrap +msgid "" +".num:\n" +"\t; See if you got a number\n" +"\tcmp\tal, '0'\n" +"\tjl\t.bigloop\n" +"\tcmp\tal, '9'\n" +"\tja\t.bigloop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3674 +#, no-wrap +msgid "" +"\t; Yes, we have a number\n" +"\tsub\tebp, ebp\n" +"\tsub\tedx, edx\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3679 +#, no-wrap +msgid "" +".number:\n" +"\tcmp\tal, '0'\n" +"\tje\t.number0\n" +"\tmov\tdl, 1\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3690 +#, no-wrap +msgid "" +".number0:\n" +"\tor\tdl, dl\t\t; Skip leading 0's\n" +"\tje\t.nextnumber\n" +"\tpush\teax\n" +"\tcall\tputchar\n" +"\tpop\teax\n" +"\tinc\tebp\n" +"\tcmp\tebp, 19\n" +"\tjae\t.nextnumber\n" +"\tmov\t[dbuffer+ebp], al\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3701 +#, no-wrap +msgid "" +".nextnumber:\n" +"\tcall\tgetchar\n" +"\tjc\t.work\n" +"\tcmp\tal, '#'\n" +"\tje\t.ungetc\n" +"\tcmp\tal, '0'\n" +"\tjl\t.work\n" +"\tcmp\tal, '9'\n" +"\tja\t.work\n" +"\tjmp\tshort .number\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3705 +#, no-wrap +msgid "" +".ungetc:\n" +"\tdec\tesi\n" +"\tinc\tebx\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3710 +#, no-wrap +msgid "" +".work:\n" +"\t; Now, do all the work\n" +"\tor\tdl, dl\n" +"\tje\tnear .work0\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3713 +#, no-wrap +msgid "" +"\tcmp\tebp, 19\n" +"\tjae\tnear .toobig\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3715 +#, no-wrap +msgid "\tcall\tbcdload\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3717 +#, no-wrap +msgid "\t; Calculate pinhole diameter\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3724 +#, no-wrap +msgid "" +"\tfld\tst0\t; save it\n" +"\tfsqrt\n" +"\tfmul\tst0, st3\n" +"\tfld\tst0\n" +"\tfmul\tst5\n" +"\tsub\tebp, ebp\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3734 +#, no-wrap +msgid "" +"\t; Round off to 4 significant digits\n" +".diameter:\n" +"\tfcom\tst0, st7\n" +"\tfstsw\tax\n" +"\tsahf\n" +"\tjb\t.printdiameter\n" +"\tfmul\tst0, st6\n" +"\tinc\tebp\n" +"\tjmp\tshort .diameter\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3737 +#, no-wrap +msgid "" +".printdiameter:\n" +"\tcall\tprintnumber\t; pinhole diameter\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3739 +#, no-wrap +msgid "\t; Calculate F-number\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3742 +#, no-wrap +msgid "" +"\tfdivp\tst1, st0\n" +"\tfld\tst0\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3744 +#, no-wrap +msgid "\tsub\tebp, ebp\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3753 +#, no-wrap +msgid "" +".fnumber:\n" +"\tfcom\tst0, st6\n" +"\tfstsw\tax\n" +"\tsahf\n" +"\tjb\t.printfnumber\n" +"\tfmul\tst0, st5\n" +"\tinc\tebp\n" +"\tjmp\tshort .fnumber\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3756 +#, no-wrap +msgid "" +".printfnumber:\n" +"\tcall\tprintnumber\t; F number\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3767 +#, no-wrap +msgid "" +"\t; Calculate normalized F-number\n" +"\tfmul\tst0, st0\n" +"\tfld1\n" +"\tfld\tst1\n" +"\tfyl2x\n" +"\tfrndint\n" +"\tfld1\n" +"\tfscale\n" +"\tfsqrt\n" +"\tfstp\tst1\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3770 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3798 +#, no-wrap +msgid "" +"\tsub\tebp, ebp\n" +"\tcall\tprintnumber\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3772 +#, no-wrap +msgid "\t; Calculate time multiplier from F-5.6\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3775 +#, no-wrap +msgid "" +"\tfscale\n" +"\tfld\tst0\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3781 +#, no-wrap +msgid "" +"\t; Round off to 4 significant digits\n" +".fmul:\n" +"\tfcom\tst0, st6\n" +"\tfstsw\tax\n" +"\tsahf\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3786 +#, no-wrap +msgid "" +"\tjb\t.printfmul\n" +"\tinc\tebp\n" +"\tfmul\tst0, st5\n" +"\tjmp\tshort .fmul\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3789 +#, no-wrap +msgid "" +".printfmul:\n" +"\tcall\tprintnumber\t; F multiplier\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3791 +#, no-wrap +msgid "\t; Calculate F-stops from 5.6\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3795 +#, no-wrap +msgid "" +"\tfld1\n" +"\tfxch\tst1\n" +"\tfyl2x\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3802 +#, no-wrap +msgid "" +"\tmov\tal, 0Ah\n" +"\tcall\tputchar\n" +"\tjmp\t.bigloop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3806 +#, no-wrap +msgid "" +".work0:\n" +"\tmov\tal, '0'\n" +"\tcall\tputchar\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3811 +#, no-wrap +msgid "" +"align 4\n" +".toobig:\n" +"\tcall\thuh\n" +"\tjmp\t.bigloop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3815 +#, no-wrap +msgid "" +"align 4\n" +"done:\n" +"\tcall\twrite\t\t; flush output buffer\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3824 +#, no-wrap +msgid "\tfinit\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3837 +#, no-wrap +msgid "" +"align 4\n" +"skiptoeol:\n" +"\t; Keep reading until you come to cr, lf, or eof\n" +"\tcall\tgetchar\n" +"\tjc\tdone\n" +"\tcmp\tal, 0Ah\n" +"\tjne\t.cr\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3842 +#, no-wrap +msgid "" +".cr:\n" +"\tcmp\tal, 0Dh\n" +"\tjne\tskiptoeol\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3855 +#, no-wrap +msgid "" +".fetch:\n" +"\tlodsb\n" +"\tdec\tebx\n" +"\tclc\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3872 +#, no-wrap +msgid "" +".read:\n" +"\tpush\tdword BUFSIZE\n" +"\tmov\tesi, ibuffer\n" +"\tpush\tesi\n" +"\tpush\tdword [fd.in]\n" +"\tsys.read\n" +"\tadd\tesp, byte 12\n" +"\tmov\tebx, eax\n" +"\tor\teax, eax\n" +"\tje\t.empty\n" +"\tsub\teax, eax\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3878 +#, no-wrap +msgid "" +"align 4\n" +".empty:\n" +"\tadd\tesp, byte 4\n" +"\tstc\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3907 +#, no-wrap +msgid "" +"align 4\n" +"bcdload:\n" +"\t; EBP contains the number of chars in dbuffer\n" +"\tpush\tecx\n" +"\tpush\tesi\n" +"\tpush\tedi\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3911 +#, no-wrap +msgid "" +"\tlea\tecx, [ebp+1]\n" +"\tlea\tesi, [dbuffer+ebp-1]\n" +"\tshr\tecx, 1\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3913 +#, no-wrap +msgid "\tstd\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3919 +#, no-wrap +msgid "" +"\tmov\tedi, bbuffer\n" +"\tsub\teax, eax\n" +"\tmov\t[edi], eax\n" +"\tmov\t[edi+4], eax\n" +"\tmov\t[edi+2], ax\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3928 +#, no-wrap +msgid "" +".loop:\n" +"\tlodsw\n" +"\tsub\tax, 3030h\n" +"\tshl\tal, 4\n" +"\tor\tal, ah\n" +"\tmov\t[edi], al\n" +"\tinc\tedi\n" +"\tloop\t.loop\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3930 +#, no-wrap +msgid "\tfbld\t[bbuffer]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3937 +#, no-wrap +msgid "" +"\tcld\n" +"\tpop\tedi\n" +"\tpop\tesi\n" +"\tpop\tecx\n" +"\tsub\teax, eax\n" +"\tret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3943 +#, no-wrap +msgid "" +"align 4\n" +"printnumber:\n" +"\tpush\tebp\n" +"\tmov\tal, [separ]\n" +"\tcall\tputchar\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3947 +#, no-wrap +msgid "" +"\t; Print the integer at the TOS\n" +"\tmov\tebp, bbuffer+9\n" +"\tfbstp\t[bbuffer]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3953 +#, no-wrap +msgid "" +"\t; Check the sign\n" +"\tmov\tal, [ebp]\n" +"\tdec\tebp\n" +"\tor\tal, al\n" +"\tjns\t.leading\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3957 +#, no-wrap +msgid "" +"\t; We got a negative number (should never happen)\n" +"\tmov\tal, '-'\n" +"\tcall\tputchar\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3966 +#, no-wrap +msgid "" +".leading:\n" +"\t; Skip leading zeros\n" +"\tmov\tal, [ebp]\n" +"\tdec\tebp\n" +"\tor\tal, al\n" +"\tjne\t.first\n" +"\tcmp\tebp, bbuffer\n" +"\tjae\t.leading\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3971 +#, no-wrap +msgid "" +"\t; We are here because the result was 0.\n" +"\t; Print '0' and return\n" +"\tmov\tal, '0'\n" +"\tjmp\tputchar\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3983 +#, no-wrap +msgid "" +".first:\n" +"\t; We have found the first non-zero.\n" +"\t; But it is still packed\n" +"\ttest\tal, 0F0h\n" +"\tjz\t.second\n" +"\tpush\teax\n" +"\tshr\tal, 4\n" +"\tadd\tal, '0'\n" +"\tcall\tputchar\n" +"\tpop\teax\n" +"\tand\tal, 0Fh\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3987 +#, no-wrap +msgid "" +".second:\n" +"\tadd\tal, '0'\n" +"\tcall\tputchar\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:3991 +#, no-wrap +msgid "" +".next:\n" +"\tcmp\tebp, bbuffer\n" +"\tjb\t.done\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4001 +#, no-wrap +msgid "" +"\tmov\tal, [ebp]\n" +"\tpush\teax\n" +"\tshr\tal, 4\n" +"\tadd\tal, '0'\n" +"\tcall\tputchar\n" +"\tpop\teax\n" +"\tand\tal, 0Fh\n" +"\tadd\tal, '0'\n" +"\tcall\tputchar\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4004 +#, no-wrap +msgid "" +"\tdec\tebp\n" +"\tjmp\tshort .next\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4009 +#, no-wrap +msgid "" +".done:\n" +"\tpop\tebp\n" +"\tor\tebp, ebp\n" +"\tje\t.ret\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4015 +#, no-wrap +msgid "" +".zeros:\n" +"\tmov\tal, '0'\n" +"\tcall\tputchar\n" +"\tdec\tebp\n" +"\tjne\t.zeros\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4018 +#, no-wrap +msgid "" +".ret:\n" +"\tret\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4021 +msgid "" +"The code follows the same format as all the other filters we have seen " +"before, with one subtle exception:" +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4024 +msgid "" +"We are no longer assuming that the end of input implies the end of things to " +"do, something we took for granted in the _character-oriented_ filters." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4026 +msgid "" +"This filter does not process characters. It processes a _language_ (albeit a " +"very simple one, consisting only of numbers)." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4028 +msgid "When we have no more input, it can mean one of two things:" +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4030 +msgid "We are done and can quit. This is the same as before." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4031 +msgid "" +"The last character we have read was a digit. We have stored it at the end of " +"our ASCII-to-float conversion buffer. We now need to convert the contents of " +"that buffer into a number and write the last line of our output." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4033 +msgid "" +"For that reason, we have modified our `getchar` and our `read` routines to " +"return with the `carry flag` _clear_ whenever we are fetching another " +"character from the input, or the `carry flag` _set_ whenever there is no " +"more input." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4036 +msgid "" +"Of course, we are still using assembly language magic to do that! Take a " +"good look at `getchar`. It _always_ returns with the `carry flag` _clear_." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4038 +msgid "" +"Yet, our main code relies on the `carry flag` to tell it when to quit-and it " +"works." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4041 +msgid "" +"The magic is in `read`. Whenever it receives more input from the system, it " +"just returns to `getchar`, which fetches a character from the input buffer, " +"_clears_ the `carry flag` and returns." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4044 +msgid "" +"But when `read` receives no more input from the system, it does _not_ return " +"to `getchar` at all. Instead, the `add esp, byte 4` op code adds `4` to " +"`ESP`, _sets_ the `carry flag`, and returns." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4048 +msgid "" +"So, where does it return to? Whenever a program uses the `call` op code, the " +"microprocessor ``push``es the return address, i.e., it stores it on the top " +"of the stack (not the FPU stack, the system stack, which is in the memory). " +"When a program uses the `ret` op code, the microprocessor ``pop``s the " +"return value from the stack, and jumps to the address that was stored there." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4050 +msgid "" +"But since we added `4` to `ESP` (which is the stack pointer register), we " +"have effectively given the microprocessor a minor case of _amnesia_: It no " +"longer remembers it was `getchar` that ``call``ed `read`." +msgstr "" + +#. type: delimited block _ 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4052 +msgid "" +"And since `getchar` never ``push``ed anything before ``call``ing `read`, the " +"top of the stack now contains the return address to whatever or whoever " +"``call``ed `getchar`. As far as that caller is concerned, he ``call``ed " +"`getchar`, which ``ret``urned with the `carry flag` set!" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4055 +msgid "" +"Other than that, the `bcdload` routine is caught up in the middle of a " +"Lilliputian conflict between the Big-Endians and the Little-Endians." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4057 +msgid "" +"It is converting the text representation of a number into that number: The " +"text is stored in the big-endian order, but the _packed decimal_ is little-" +"endian." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4060 +msgid "" +"To solve the conflict, we use the `std` op code early on. We cancel it with " +"`cld` later on: It is quite important we do not `call` anything that may " +"depend on the default setting of the _direction flag_ while `std` is active." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4062 +msgid "" +"Everything else in this code should be quit eclear, providing you have read " +"the entire chapter that precedes it." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4065 +msgid "" +"It is a classical example of the adage that programming requires a lot of " +"thought and only a little coding. Once we have thought through every tiny " +"detail, the code almost writes itself." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4067 +#, no-wrap +msgid "Using pinhole" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4071 +msgid "" +"Because we have decided to make the program _ignore_ any input except for " +"numbers (and even those inside a comment), we can actually perform _textual " +"queries_. We do not _have to_, but we _can_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4073 +msgid "" +"In my humble opinion, forming a textual query, instead of having to follow a " +"very strict syntax, makes software much more user friendly." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4079 +msgid "" +"Suppose we want to build a pinhole camera to use the 4x5 inch film. The " +"standard focal length for that film is about 150mm. We want to _fine-tune_ " +"our focal length so the pinhole diameter is as round a number as possible. " +"Let us also suppose we are quite comfortable with cameras but somewhat " +"intimidated by computers. Rather than just have to type in a bunch of " +"numbers, we want to _ask_ a couple of questions." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4081 +msgid "Our session might look like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4085 +#, no-wrap +msgid "% pinhole\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4087 +#, no-wrap +msgid "Computer,\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4100 +#, no-wrap +msgid "" +"What size pinhole do I need for the focal length of 150?\n" +"150\t490\t306\t362\t2930\t12\n" +"Hmmm... How about 160?\n" +"160\t506\t316\t362\t3125\t12\n" +"Let's make it 155, please.\n" +"155\t498\t311\t362\t3027\t12\n" +"Ah, let's try 157...\n" +"157\t501\t313\t362\t3066\t12\n" +"156?\n" +"156\t500\t312\t362\t3047\t12\n" +"That's it! Perfect! Thank you very much!\n" +"^D\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4103 +msgid "" +"We have found that while for the focal length of 150, our pinhole diameter " +"should be 490 microns, or 0.49 mm, if we go with the almost identical focal " +"length of 156 mm, we can get away with a pinhole diameter of exactly one " +"half of a millimeter." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4105 +#, no-wrap +msgid "Scripting" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4108 +msgid "" +"Because we have chosen the `+#+` character to denote the start of a comment, " +"we can treat our pinhole software as a _scripting language_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4110 +msgid "You have probably seen shell _scripts_ that start with:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4114 +#, no-wrap +msgid "#! /bin/sh\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4117 +msgid "...or..." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4121 +#, no-wrap +msgid "#!/bin/sh\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4124 +msgid "...because the blank space after the `#!` is optional." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4127 +msgid "" +"Whenever UNIX(R) is asked to run an executable file which starts with the `#!" +"`, it assumes the file is a script. It adds the command to the rest of the " +"first line of the script, and tries to execute that." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4129 +msgid "" +"Suppose now that we have installed pinhole in /usr/local/bin/, we can now " +"write a script to calculate various pinhole diameters suitable for various " +"focal lengths commonly used with the 120 film." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4131 +msgid "The script might look something like this:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4137 +#, no-wrap +msgid "" +"#! /usr/local/bin/pinhole -b -i\n" +"# Find the best pinhole diameter\n" +"# for the 120 film\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4140 +#, no-wrap +msgid "" +"### Standard\n" +"80\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4143 +#, no-wrap +msgid "" +"### Wide angle\n" +"30, 40, 50, 60, 70\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4146 +#, no-wrap +msgid "" +"### Telephoto\n" +"100, 120, 140\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4149 +msgid "Because 120 is a medium size film, we may name this file medium." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4151 +msgid "" +"We can set its permissions to execute, and run it as if it were a program:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4156 +#, no-wrap +msgid "" +"% chmod 755 medium\n" +"% ./medium\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4159 +msgid "UNIX(R) will interpret that last command as:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4163 +#, no-wrap +msgid "% /usr/local/bin/pinhole -b -i ./medium\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4166 +msgid "It will run that command and display:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4178 +#, no-wrap +msgid "" +"80\t358\t224\t256\t1562\t11\n" +"30\t219\t137\t128\t586\t9\n" +"40\t253\t158\t181\t781\t10\n" +"50\t283\t177\t181\t977\t10\n" +"60\t310\t194\t181\t1172\t10\n" +"70\t335\t209\t181\t1367\t10\n" +"100\t400\t250\t256\t1953\t11\n" +"120\t438\t274\t256\t2344\t11\n" +"140\t473\t296\t256\t2734\t11\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4181 +msgid "Now, let us enter:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4185 +#, no-wrap +msgid "% ./medium -c\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4188 +msgid "UNIX(R) will treat that as:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4192 +#, no-wrap +msgid "% /usr/local/bin/pinhole -b -i ./medium -c\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4196 +msgid "" +"That gives it two conflicting options: `-b` and `-c` (Use Bender's constant " +"and use Connors' constant). We have programmed it so later options override " +"early ones-our program will calculate everything using Connors' constant:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4208 +#, no-wrap +msgid "" +"80\t331\t242\t256\t1826\t11\n" +"30\t203\t148\t128\t685\t9\n" +"40\t234\t171\t181\t913\t10\n" +"50\t262\t191\t181\t1141\t10\n" +"60\t287\t209\t181\t1370\t10\n" +"70\t310\t226\t256\t1598\t11\n" +"100\t370\t270\t256\t2283\t11\n" +"120\t405\t296\t256\t2739\t11\n" +"140\t438\t320\t362\t3196\t12\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4212 +msgid "" +"We decide we want to go with Bender's constant after all. We want to save " +"its values as a comma-separated file:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4228 +#, no-wrap +msgid "" +"% ./medium -b -e > bender\n" +"% cat bender\n" +"focal length in millimeters,pinhole diameter in microns,F-number,normalized F-number,F-5.6 multiplier,stops from F-5.6\n" +"80,358,224,256,1562,11\n" +"30,219,137,128,586,9\n" +"40,253,158,181,781,10\n" +"50,283,177,181,977,10\n" +"60,310,194,181,1172,10\n" +"70,335,209,181,1367,10\n" +"100,400,250,256,1953,11\n" +"120,438,274,256,2344,11\n" +"140,473,296,256,2734,11\n" +"%\n" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4231 +#, no-wrap +msgid "Caveats" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4235 +msgid "" +"Assembly language programmers who \"grew up\" under MS-DOS(R) and Windows(R) " +"often tend to take shortcuts. Reading the keyboard scan codes and writing " +"directly to video memory are two classical examples of practices which, " +"under MS-DOS(R) are not frowned upon but considered the right thing to do." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4237 +msgid "" +"The reason? Both the PC BIOS and MS-DOS(R) are notoriously slow when " +"performing these operations." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4240 +msgid "" +"You may be tempted to continue similar practices in the UNIX(R) " +"environment. For example, I have seen a web site which explains how to " +"access the keyboard scan codes on a popular UNIX(R) clone." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4242 +msgid "" +"That is generally a _very bad idea_ in UNIX(R) environment! Let me explain " +"why." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4244 +#, no-wrap +msgid "UNIX(R) Is Protected" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4251 +msgid "" +"For one thing, it may simply not be possible. UNIX(R) runs in protected " +"mode. Only the kernel and device drivers are allowed to access hardware " +"directly. Perhaps a particular UNIX(R) clone will let you read the keyboard " +"scan codes, but chances are a real UNIX(R) operating system will not. And " +"even if one version may let you do it, the next one may not, so your " +"carefully crafted software may become a dinosaur overnight." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4253 +#, no-wrap +msgid "UNIX(R) Is an Abstraction" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4256 +msgid "" +"But there is a much more important reason not to try accessing the hardware " +"directly (unless, of course, you are writing a device driver), even on the " +"UNIX(R) like systems that let you do it:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4258 +msgid "_UNIX(R) is an abstraction!_" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4264 +msgid "" +"There is a major difference in the philosophy of design between MS-DOS(R) " +"and UNIX(R). MS-DOS(R) was designed as a single-user system. It is run on " +"a computer with a keyboard and a video screen attached directly to that " +"computer. User input is almost guaranteed to come from that keyboard. Your " +"program's output virtually always ends up on that screen." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4267 +msgid "" +"This is NEVER guaranteed under UNIX(R). It is quite common for a UNIX(R) " +"user to pipe and redirect program input and output:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4271 +#, no-wrap +msgid "% program1 | program2 | program3 > file1\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4275 +msgid "" +"If you have written program2, your input does not come from the keyboard but " +"from the output of program1. Similarly, your output does not go to the " +"screen but becomes the input for program3 whose output, in turn, goes to [." +"filename]#file1#." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4278 +msgid "" +"But there is more! Even if you made sure that your input comes from, and " +"your output goes to, the terminal, there is no guarantee the terminal is a " +"PC: It may not have its video memory where you expect it, nor may its " +"keyboard be producing PC-style scan codes. It may be a Macintosh(R), or any " +"other computer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4280 +msgid "" +"Now you may be shaking your head: My software is in PC assembly language, " +"how can it run on a Macintosh(R)? But I did not say your software would be " +"running on a Macintosh(R), only that its terminal may be a Macintosh(R)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4284 +msgid "" +"Under UNIX(R), the terminal does not have to be directly attached to the " +"computer that runs your software, it can even be on another continent, or, " +"for that matter, on another planet. It is perfectly possible that a " +"Macintosh(R) user in Australia connects to a UNIX(R) system in North America " +"(or anywhere else) via telnet. The software then runs on one computer, " +"while the terminal is on a different computer: If you try to read the scan " +"codes, you will get the wrong input!" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4287 +msgid "" +"Same holds true about any other hardware: A file you are reading may be on a " +"disk you have no direct access to. A camera you are reading images from may " +"be on a space shuttle, connected to you via satellites." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4290 +msgid "" +"That is why under UNIX(R) you must never make any assumptions about where " +"your data is coming from and going to. Always let the system handle the " +"physical access to the hardware." +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4298 +msgid "" +"These are caveats, not absolute rules. Exceptions are possible. For " +"example, if a text editor has determined it is running on a local machine, " +"it may want to read the scan codes directly for improved control. I am not " +"mentioning these caveats to tell you what to do or what not to do, just to " +"make you aware of certain pitfalls that await you if you have just arrived " +"to UNIX(R) form MS-DOS(R). Of course, creative people often break rules, " +"and it is OK as long as they know they are breaking them and why." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4301 +#, no-wrap +msgid "Acknowledgements" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4304 +msgid "" +"This tutorial would never have been possible without the help of many " +"experienced FreeBSD programmers from the {freebsd-hackers}, many of whom " +"have patiently answered my questions, and pointed me in the right direction " +"in my attempts to explore the inner workings of UNIX(R) system programming " +"in general and FreeBSD in particular." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4307 +msgid "" +"Thomas M. Sommers opened the door for me . His https://web.archive.org/" +"web/20090914064615/http://www.codebreakers-journal.com/content/" +"view/262/27[How do I write \"Hello, world\" in FreeBSD assembler?] web page " +"was my first encounter with an example of assembly language programming " +"under FreeBSD." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/developers-handbook/x86/_index.adoc:4309 +msgid "" +"Jake Burkholder has kept the door open by willingly answering all of my " +"questions and supplying me with example assembly language source code." +msgstr "" |