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Diffstat (limited to 'secure/lib/libcrypto/man/BIO_s_mem.3')
| -rw-r--r-- | secure/lib/libcrypto/man/BIO_s_mem.3 | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/secure/lib/libcrypto/man/BIO_s_mem.3 b/secure/lib/libcrypto/man/BIO_s_mem.3 new file mode 100644 index 000000000000..779d83538bf6 --- /dev/null +++ b/secure/lib/libcrypto/man/BIO_s_mem.3 @@ -0,0 +1,256 @@ +.\" Automatically generated by Pod::Man version 1.15 +.\" Thu May 9 13:16:02 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. 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Data +written to a memory \s-1BIO\s0 is stored in a \s-1BUF_MEM\s0 structure which is extended +as appropriate to accommodate the stored data. +.PP +Any data written to a memory \s-1BIO\s0 can be recalled by reading from it. +Unless the memory \s-1BIO\s0 is read only any data read from it is deleted from +the \s-1BIO\s0. +.PP +Memory BIOs support \fIBIO_gets()\fR and \fIBIO_puts()\fR. +.PP +If the \s-1BIO_CLOSE\s0 flag is set when a memory \s-1BIO\s0 is freed then the underlying +\&\s-1BUF_MEM\s0 structure is also freed. +.PP +Calling \fIBIO_reset()\fR on a read write memory \s-1BIO\s0 clears any data in it. On a +read only \s-1BIO\s0 it restores the \s-1BIO\s0 to its original state and the read only +data can be read again. +.PP +\&\fIBIO_eof()\fR is true if no data is in the \s-1BIO\s0. +.PP +\&\fIBIO_ctrl_pending()\fR returns the number of bytes currently stored. +.PP +\&\fIBIO_set_mem_eof_return()\fR sets the behaviour of memory \s-1BIO\s0 \fBb\fR when it is +empty. If the \fBv\fR is zero then an empty memory \s-1BIO\s0 will return \s-1EOF\s0 (that is +it will return zero and \fIBIO_should_retry\fR\|(b) will be false. If \fBv\fR is non +zero then it will return \fBv\fR when it is empty and it will set the read retry +flag (that is \fIBIO_read_retry\fR\|(b) is true). To avoid ambiguity with a normal +positive return value \fBv\fR should be set to a negative value, typically \-1. +.PP +\&\fIBIO_get_mem_data()\fR sets \fBpp\fR to a pointer to the start of the memory BIOs data +and returns the total amount of data available. It is implemented as a macro. +.PP +\&\fIBIO_set_mem_buf()\fR sets the internal \s-1BUF_MEM\s0 structure to \fBbm\fR and sets the +close flag to \fBc\fR, that is \fBc\fR should be either \s-1BIO_CLOSE\s0 or \s-1BIO_NOCLOSE\s0. +It is a macro. +.PP +\&\fIBIO_get_mem_ptr()\fR places the underlying \s-1BUF_MEM\s0 structure in \fBpp\fR. It is +a macro. +.PP +\&\fIBIO_new_mem_buf()\fR creates a memory \s-1BIO\s0 using \fBlen\fR bytes of data at \fBbuf\fR, +if \fBlen\fR is \-1 then the \fBbuf\fR is assumed to be null terminated and its +length is determined by \fBstrlen\fR. The \s-1BIO\s0 is set to a read only state and +as a result cannot be written to. This is useful when some data needs to be +made available from a static area of memory in the form of a \s-1BIO\s0. The +supplied data is read directly from the supplied buffer: it is \fBnot\fR copied +first, so the supplied area of memory must be unchanged until the \s-1BIO\s0 is freed. +.SH "NOTES" +.IX Header "NOTES" +Writes to memory BIOs will always succeed if memory is available: that is +their size can grow indefinitely. +.PP +Every read from a read write memory \s-1BIO\s0 will remove the data just read with +an internal copy operation, if a \s-1BIO\s0 contains a lots of data and it is +read in small chunks the operation can be very slow. The use of a read only +memory \s-1BIO\s0 avoids this problem. If the \s-1BIO\s0 must be read write then adding +a buffering \s-1BIO\s0 to the chain will speed up the process. +.SH "BUGS" +.IX Header "BUGS" +There should be an option to set the maximum size of a memory \s-1BIO\s0. +.PP +There should be a way to \*(L"rewind\*(R" a read write \s-1BIO\s0 without destroying +its contents. +.PP +The copying operation should not occur after every small read of a large \s-1BIO\s0 +to improve efficiency. +.SH "EXAMPLE" +.IX Header "EXAMPLE" +Create a memory \s-1BIO\s0 and write some data to it: +.PP +.Vb 2 +\& BIO *mem = BIO_new(BIO_s_mem()); +\& BIO_puts(mem, "Hello World\en"); +.Ve +Create a read only memory \s-1BIO:\s0 +.PP +.Vb 3 +\& char data[] = "Hello World"; +\& BIO *mem; +\& mem = BIO_new_mem_buf(data, -1); +.Ve +Extract the \s-1BUF_MEM\s0 structure from a memory \s-1BIO\s0 and then free up the \s-1BIO:\s0 +.PP +.Vb 4 +\& BUF_MEM *bptr; +\& BIO_get_mem_ptr(mem, &bptr); +\& BIO_set_close(mem, BIO_NOCLOSE); /* So BIO_free() leaves BUF_MEM alone */ +\& BIO_free(mem); +.Ve +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\s-1TBA\s0 |