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Diffstat (limited to 'lib/libc/stdio/open_memstream.3')
| -rw-r--r-- | lib/libc/stdio/open_memstream.3 | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/lib/libc/stdio/open_memstream.3 b/lib/libc/stdio/open_memstream.3 new file mode 100644 index 00000000000..f081fd8849b --- /dev/null +++ b/lib/libc/stdio/open_memstream.3 @@ -0,0 +1,106 @@ +.\" $OpenBSD: open_memstream.3,v 1.1 2013/01/01 17:41:13 mpi Exp $ +.\" +.\" Copyright (c) 2011 Martin Pieuchot <mpi@openbsd.org> +.\" +.\" Permission to use, copy, modify, and distribute this software for any +.\" purpose with or without fee is hereby granted, provided that the above +.\" copyright notice and this permission notice appear in all copies. +.\" +.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +.\" +.Dd $Mdocdate: January 1 2013 $ +.Dt OPEN_MEMSTREAM 3 +.Os +.Sh NAME +.Nm open_memstream , +.Nm open_wmemstream +.Nd open a memory buffer stream +.Sh SYNOPSIS +.Fd #include <stdio.h> +.Ft FILE * +.Fn open_memstream "char **pbuf" "size_t *psize" +.Fd #include <wchar.h> +.Ft FILE * +.Fn open_wmemstream "wchar_t **pbuf" "size_t *psize" +.Sh DESCRIPTION +The +.Fn open_memstream +and +.Fn open_wmemstream +functions create a seekable byte-oriented, or respectively wide-oriented, +stream for writing. +A dynamically allocated buffer, using +.Xr malloc 3 , +is then wrapped to the pointer referenced by +.Fa pbuf +and grows automatically as required. +.Pp +When the stream is either closed or flushed, the address of the buffer is +stored in the pointer referenced by +.Fa pbuf . +At the same time the smaller of the current position and the buffer length is +written in the variable pointed to by +.Fa psize . +This value represents the number of bytes, or respectively wide characters, +contained in the buffer not including the terminating null character. +.Pp +The buffer memory should be release after the stream is closed. +.Sh RETURN VALUES +Upon successful completion, +.Fn open_memstream +and +.Fn open_wmemstream +return a +.Dv FILE +pointer. +Otherwise, +.Dv NULL +is returned and the global variable +.Va errno +is set to indicate the error. +.Sh ERRORS +.Bl -tag -width Er +.It Bq Er EINVAL +The +.Fa pbuf +or the +.Fa psize +argument is +.Dv NULL . +.El +.Pp +The +.Fn open_memstream +and +.Fn open_wmemstream +functions +may also fail and set +.Va errno +for any of the errors +specified for the routine +.Xr malloc 3 . +.Sh SEE ALSO +.Xr fmemopen 3 , +.Xr funopen 3 , +.Xr fopen 3 , +.Xr malloc 3 +.Sh STANDARDS +The functions +.Fn open_memstream +and +.Fn open_wmemstream , +conform to +.St -p1003.1-2008 . +.Sh HISTORY +The +.Fn open_memstream +and +.Fn open_wmemstream +functions first appeared in +.Ox 5.3 . |