forked from Mirrors/wine-wine
51 lines
1.5 KiB
C
51 lines
1.5 KiB
C
/*
|
|
* pread function
|
|
*
|
|
* Copyright 1996 Alexandre Julliard
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* This 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
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
|
|
*/
|
|
|
|
#include "config.h"
|
|
#include "wine/port.h"
|
|
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#ifdef HAVE_UNISTD_H
|
|
# include <unistd.h>
|
|
#endif
|
|
|
|
/* FIXME: this is not thread-safe */
|
|
|
|
#ifndef HAVE_PREAD
|
|
ssize_t pread( int fd, void *buf, size_t count, off_t offset )
|
|
{
|
|
ssize_t ret;
|
|
off_t old_pos;
|
|
|
|
if ((old_pos = lseek( fd, 0, SEEK_CUR )) == -1) return -1;
|
|
if (lseek( fd, offset, SEEK_SET ) == -1) return -1;
|
|
if ((ret = read( fd, buf, count )) == -1)
|
|
{
|
|
int err = errno; /* save errno */
|
|
lseek( fd, old_pos, SEEK_SET );
|
|
errno = err;
|
|
return -1;
|
|
}
|
|
if (lseek( fd, old_pos, SEEK_SET ) == -1) return -1;
|
|
return ret;
|
|
}
|
|
#endif /* HAVE_PREAD */
|