mirror of
https://github.com/coreutils/coreutils.git
synced 2024-11-24 18:33:47 +08:00
49 lines
1.4 KiB
C
49 lines
1.4 KiB
C
/* Invoke open, but return either a desired file descriptor or -1.
|
|
|
|
Copyright (C) 2005, 2006 Free Software Foundation, Inc.
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
/* Written by Paul Eggert. */
|
|
|
|
#include <config.h>
|
|
|
|
#include "fd-reopen.h"
|
|
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <unistd.h>
|
|
|
|
/* Open a file to a particular file descriptor. This is like standard
|
|
`open', except it always returns DESIRED_FD if successful. */
|
|
|
|
int
|
|
fd_reopen (int desired_fd, char const *file, int flags, mode_t mode)
|
|
{
|
|
int fd;
|
|
|
|
close (desired_fd);
|
|
fd = open (file, flags, mode);
|
|
if (fd == desired_fd || fd < 0)
|
|
return fd;
|
|
else
|
|
{
|
|
int fd2 = fcntl (fd, F_DUPFD, desired_fd);
|
|
int saved_errno = errno;
|
|
close (fd);
|
|
errno = saved_errno;
|
|
return fd2;
|
|
}
|
|
}
|