mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-14 01:00:07 +00:00
109 lines
3.2 KiB
C
109 lines
3.2 KiB
C
/* Copyright (C) 1991, 1992, 1993 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public License as
|
|
published by the Free Software Foundation; either version 2 of the
|
|
License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If
|
|
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
|
|
Cambridge, MA 02139, USA. */
|
|
|
|
#include <ansidecl.h>
|
|
#include <errno.h>
|
|
#include <stddef.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
|
|
/* Defined in fopen.c. */
|
|
extern int EXFUN(__getmode, (CONST char *mode, __io_mode *mptr));
|
|
|
|
/* Open a new stream that will read and/or write from the buffer in
|
|
S, which is of LEN bytes. If the mode indicates appending, the
|
|
buffer pointer is set to point to the first '\0' in the buffer.
|
|
If S is NULL, the buffer is allocated by malloc and will be freed
|
|
when the stream is closed. The only purpose of this is to write
|
|
things and then read what's been written. If LEN is zero, writes will
|
|
always return errors and reads will always return end-of-file.
|
|
|
|
The stream is set up such that seeks and tells will always fail and
|
|
once the buffer is full of written characters or empty of characters
|
|
to read, attempted writes always return an output error and attempted
|
|
reads always return end-of-file. */
|
|
FILE *
|
|
DEFUN(fmemopen, (s, len, mode),
|
|
PTR s AND size_t len AND CONST char *mode)
|
|
{
|
|
__io_mode m;
|
|
register FILE *stream;
|
|
|
|
if (!__getmode (mode, &m))
|
|
return NULL;
|
|
|
|
stream = __newstream ();
|
|
if (stream == NULL)
|
|
return NULL;
|
|
|
|
stream->__mode = m;
|
|
|
|
/* Input gets EOF. */
|
|
stream->__room_funcs.__input = NULL;
|
|
/* Output gets error. */
|
|
stream->__room_funcs.__output = NULL;
|
|
|
|
/* Do nothing for close. */
|
|
stream->__io_funcs.__close = NULL;
|
|
/* Can't seek outside the buffer. */
|
|
stream->__io_funcs.__seek = NULL;
|
|
/* There is no associated file descriptor to fetch. */
|
|
stream->__io_funcs.__fileno = NULL;
|
|
|
|
stream->__seen = 1;
|
|
|
|
stream->__userbuf = s != NULL && len > 0;
|
|
if (s == NULL)
|
|
{
|
|
s = malloc (len);
|
|
if (s == NULL)
|
|
{
|
|
int save = errno;
|
|
(void) fclose (stream);
|
|
errno = save;
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
stream->__buffer = (char *) s;
|
|
stream->__bufsize = len;
|
|
|
|
stream->__bufp = stream->__buffer;
|
|
stream->__get_limit = (stream->__buffer +
|
|
(stream->__mode.__read ? stream->__bufsize : 0));
|
|
stream->__put_limit = (stream->__buffer +
|
|
(stream->__mode.__write ? stream->__bufsize : 0));
|
|
stream->__cookie = NULL;
|
|
|
|
if (stream->__mode.__append)
|
|
{
|
|
char *p = memchr (stream->__bufp, '\0',
|
|
stream->__get_limit - stream->__bufp);
|
|
if (p == NULL)
|
|
stream->__bufp = stream->__get_limit;
|
|
else
|
|
stream->__bufp = p;
|
|
}
|
|
else if (stream->__mode.__truncate)
|
|
memset ((PTR) stream->__buffer, 0, len);
|
|
|
|
return stream;
|
|
}
|