diff options
Diffstat (limited to 'secure/lib/libcrypto/man/BIO_read.3')
| -rw-r--r-- | secure/lib/libcrypto/man/BIO_read.3 | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/secure/lib/libcrypto/man/BIO_read.3 b/secure/lib/libcrypto/man/BIO_read.3 new file mode 100644 index 000000000000..9b0b5baa2690 --- /dev/null +++ b/secure/lib/libcrypto/man/BIO_read.3 @@ -0,0 +1,203 @@ +.\" Automatically generated by Pod::Man version 1.15 +.\" Thu May 9 13:15:48 2002 +.\" +.\" Standard preamble: +.\" ====================================================================== +.de Sh \" Subsection heading +.br +.if t .Sp +.ne 5 +.PP +\fB\\$1\fR +.PP +.. +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Ip \" List item +.br +.ie \\n(.$>=3 .ne \\$3 +.el .ne 3 +.IP "\\$1" \\$2 +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R + +.fi +.. +.\" Set up some character translations and predefined strings. \*(-- will +.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left +.\" double quote, and \*(R" will give a right double quote. | will give a +.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used +.\" to do unbreakable dashes and therefore won't be available. \*(C` and +.\" \*(C' expand to `' in nroff, nothing in troff, for use with C<> +.tr \(*W-|\(bv\*(Tr +.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' +.ie n \{\ +. ds -- \(*W- +. ds PI pi +. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch +. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch +. ds L" "" +. ds R" "" +. ds C` "" +. ds C' "" +'br\} +.el\{\ +. ds -- \|\(em\| +. ds PI \(*p +. ds L" `` +. ds R" '' +'br\} +.\" +.\" If the F register is turned on, we'll generate index entries on stderr +.\" for titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and +.\" index entries marked with X<> in POD. Of course, you'll have to process +.\" the output yourself in some meaningful fashion. +.if \nF \{\ +. de IX +. tm Index:\\$1\t\\n%\t"\\$2" +.. +. nr % 0 +. rr F +.\} +.\" +.\" For nroff, turn off justification. Always turn off hyphenation; it +.\" makes way too many mistakes in technical documents. +.hy 0 +.if n .na +.\" +.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). +.\" Fear. Run. Save yourself. No user-serviceable parts. +.bd B 3 +. \" fudge factors for nroff and troff +.if n \{\ +. ds #H 0 +. ds #V .8m +. ds #F .3m +. ds #[ \f1 +. ds #] \fP +.\} +.if t \{\ +. ds #H ((1u-(\\\\n(.fu%2u))*.13m) +. ds #V .6m +. ds #F 0 +. ds #[ \& +. ds #] \& +.\} +. \" simple accents for nroff and troff +.if n \{\ +. ds ' \& +. ds ` \& +. ds ^ \& +. ds , \& +. ds ~ ~ +. ds / +.\} +.if t \{\ +. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" +. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' +. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' +. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' +. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' +. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' +.\} +. \" troff and (daisy-wheel) nroff accents +.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' +.ds 8 \h'\*(#H'\(*b\h'-\*(#H' +.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] +.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' +.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' +.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] +.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] +.ds ae a\h'-(\w'a'u*4/10)'e +.ds Ae A\h'-(\w'A'u*4/10)'E +. \" corrections for vroff +.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' +.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' +. \" for low resolution devices (crt and lpr) +.if \n(.H>23 .if \n(.V>19 \ +\{\ +. ds : e +. ds 8 ss +. ds o a +. ds d- d\h'-1'\(ga +. ds D- D\h'-1'\(hy +. ds th \o'bp' +. ds Th \o'LP' +. ds ae ae +. ds Ae AE +.\} +.rm #[ #] #H #V #F C +.\" ====================================================================== +.\" +.IX Title "BIO_READ 1" +.TH BIO_READ 1 "perl v5.6.1" "2000-11-13" "User Contributed Perl Documentation" +.UC +.SH "NAME" +BIO_read, BIO_write, BIO_gets, BIO_puts \- \s-1BIO\s0 I/O functions +.SH "SYNOPSIS" +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/bio.h> +.Ve +.Vb 4 +\& int BIO_read(BIO *b, void *buf, int len); +\& int BIO_gets(BIO *b,char *buf, int size); +\& int BIO_write(BIO *b, const void *buf, int len); +\& int BIO_puts(BIO *b,const char *buf); +.Ve +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +\&\fIBIO_read()\fR attempts to read \fBlen\fR bytes from \s-1BIO\s0 \fBb\fR and places +the data in \fBbuf\fR. +.PP +\&\fIBIO_gets()\fR performs the BIOs \*(L"gets\*(R" operation and places the data +in \fBbuf\fR. Usually this operation will attempt to read a line of data +from the \s-1BIO\s0 of maximum length \fBlen\fR. There are exceptions to this +however, for example \fIBIO_gets()\fR on a digest \s-1BIO\s0 will calculate and +return the digest and other BIOs may not support \fIBIO_gets()\fR at all. +.PP +\&\fIBIO_write()\fR attempts to write \fBlen\fR bytes from \fBbuf\fR to \s-1BIO\s0 \fBb\fR. +.PP +\&\fIBIO_puts()\fR attempts to write a null terminated string \fBbuf\fR to \s-1BIO\s0 \fBb\fR +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +All these functions return either the amount of data successfully read or +written (if the return value is positive) or that no data was successfully +read or written if the result is 0 or \-1. If the return value is \-2 then +the operation is not implemented in the specific \s-1BIO\s0 type. +.SH "NOTES" +.IX Header "NOTES" +A 0 or \-1 return is not necessarily an indication of an error. In +particular when the source/sink is non-blocking or of a certain type +it may merely be an indication that no data is currently available and that +the application should retry the operation later. +.PP +One technique sometimes used with blocking sockets is to use a system call +(such as \fIselect()\fR, \fIpoll()\fR or equivalent) to determine when data is available +and then call \fIread()\fR to read the data. The equivalent with BIOs (that is call +\&\fIselect()\fR on the underlying I/O structure and then call \fIBIO_read()\fR to +read the data) should \fBnot\fR be used because a single call to \fIBIO_read()\fR +can cause several reads (and writes in the case of \s-1SSL\s0 BIOs) on the underlying +I/O structure and may block as a result. Instead \fIselect()\fR (or equivalent) +should be combined with non blocking I/O so successive reads will request +a retry instead of blocking. +.PP +See BIO_should_retry(3) for details of how to +determine the cause of a retry and other I/O issues. +.PP +If the \fIBIO_gets()\fR function is not supported by a \s-1BIO\s0 then it possible to +work around this by adding a buffering \s-1BIO\s0 BIO_f_buffer(3) +to the chain. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +BIO_should_retry(3) +.PP +\&\s-1TBA\s0 |