tmate/compat/openat.c
2014-11-08 12:27:43 +00:00

62 lines
1.5 KiB
C

/*
* Copyright (c) 2013 Nicholas Marriott <nicm@users.sourceforge.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <unistd.h>
#include "tmux.h"
int
openat(int fd, const char *path, int flags, ...)
{
mode_t mode;
va_list ap;
int dotfd, retval, saved_errno;
if (flags & O_CREAT) {
va_start(ap, flags);
mode = va_arg(ap, mode_t);
va_end(ap);
} else
mode = 0;
dotfd = -1;
if (fd != AT_FDCWD) {
dotfd = open(".", O_RDONLY);
if (dotfd == -1)
return (-1);
if (fchdir(fd) != 0)
return (-1);
}
retval = open(path, flags, mode);
if (dotfd != -1) {
if (fchdir(dotfd) != 0) {
saved_errno = errno;
close(retval);
close(dotfd);
errno = saved_errno;
return (-1);
}
close(dotfd);
}
return (retval);
}