glibc/stdio/fopen.c
Thomas Bushnell, BSG ebe3b3ebb7 Fri Nov 15 12:27:25 1996 Thomas Bushnell, n/BSG <thomas@gnu.ai.mit.edu>
* sysdeps/posix/readv.c (readv): Change return type to ssize_t.
  	Deansideclized.
	* sysdeps/posix/writev.c (writev): Likewise.
1996-11-15 19:50:04 +00:00

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/* Copyright (C) 1991, 1992, 1993, 1996 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 <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define badmode() return ((__set_errno (EINVAL)), 0)
/* Dissect the given mode string into an __io_mode. */
int
__getmode (const char *mode, __io_mode *mptr)
{
register unsigned char i;
if (mode == NULL)
badmode ();
memset ((void *) mptr, 0, sizeof (*mptr));
switch (*mode)
{
case 'a':
mptr->__write = mptr->__create = mptr->__append = 1;
break;
case 'w':
mptr->__write = mptr->__create = mptr->__truncate = 1;
break;
case 'r':
mptr->__read = 1;
break;
default:
badmode ();
}
for (i = 1; i < 3; ++i)
{
++mode;
if (*mode == '\0')
break;
switch (*mode)
{
case '+':
mptr->__read = mptr->__write = 1;
break;
case 'b':
mptr->__binary = 1;
break;
}
}
if (!mptr->__read && !mptr->__write)
badmode ();
mptr->__exclusive = *mode == 'x';
return 1;
}
/* Open a new stream on the given file. */
FILE *
fopen (filename, mode)
const char *filename;
const char *mode;
{
FILE *stream;
__io_mode m;
if (filename == NULL)
{
__set_errno (EINVAL);
return NULL;
}
if (!__getmode (mode, &m))
return NULL;
stream = __newstream ();
if (stream == NULL)
return NULL;
if (__stdio_open (filename, m, &stream->__cookie))
{
int save = errno;
(void) fclose (stream);
__set_errno (save);
return NULL;
}
stream->__mode = m;
return stream;
}