mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-14 09:01:07 +00:00
131c6eb7da
* sysdeps/generic/bits/ustat.h: Comment fix. * io/sys/sendfile.h: Comment fix. * sysdeps/posix/pread.c: Comment fix. * sysdeps/posix/pread64.c: Comment fix. * sysdeps/posix/pwrite.c: Comment fix. * sysdeps/posix/pwrite64.c: Comment fix.
65 lines
2.2 KiB
C
65 lines
2.2 KiB
C
/* Write block to given position in file without changing file pointer.
|
|
POSIX version.
|
|
Copyright (C) 1997, 1998, 1999, 2000, 2002 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
|
|
|
|
The GNU C 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.
|
|
|
|
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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
|
|
/* Note: This implementation of pwrite64 is not multithread-safe. */
|
|
|
|
ssize_t
|
|
__libc_pwrite64 (int fd, const void *buf, size_t nbyte, off64_t offset)
|
|
{
|
|
/* Since we must not change the file pointer preserve the value so that
|
|
we can restore it later. */
|
|
int save_errno;
|
|
ssize_t result;
|
|
off64_t old_offset = __libc_lseek64 (fd, 0, SEEK_CUR);
|
|
if (old_offset == (off64_t) -1)
|
|
return -1;
|
|
|
|
/* Set to wanted position. */
|
|
if (__libc_lseek64 (fd, offset, SEEK_SET) == (off64_t) -1)
|
|
return -1;
|
|
|
|
/* Write out the data. */
|
|
result = __libc_write (fd, buf, nbyte);
|
|
|
|
/* Now we have to restore the position. If this fails we have to
|
|
return this as an error. But if the writing also failed we
|
|
return this error. */
|
|
save_errno = errno;
|
|
if (__libc_lseek64 (fd, old_offset, SEEK_SET) == (off64_t) -1)
|
|
{
|
|
if (result == -1)
|
|
__set_errno (save_errno);
|
|
return -1;
|
|
}
|
|
__set_errno (save_errno);
|
|
|
|
return result;
|
|
}
|
|
#ifndef __libc_pwrite64
|
|
libc_hidden_def (__libc_pwrite64)
|
|
weak_alias (__libc_pwrite64, __pwrite64)
|
|
libc_hidden_weak (__pwrite64)
|
|
weak_alias (__libc_pwrite64, pwrite64)
|
|
#endif
|