1 /* Invoke pipe, but avoid some glitches.
2 Copyright (C) 2005-2006, 2009-2021 Free Software Foundation, Inc.
3
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
16
17 /* Written by Jim Meyering. */
18
19 #include <config.h>
20
21 #include "unistd-safer.h"
22
23 #include <unistd.h>
24 #include <errno.h>
25
26 /* Like pipe, but ensure that neither of the file descriptors is
27 STDIN_FILENO, STDOUT_FILENO, or STDERR_FILENO. Fail with ENOSYS on
28 platforms that lack pipe. */
29
30 int
pipe_safer(int fd[2])31 pipe_safer (int fd[2])
32 {
33 if (pipe (fd) == 0)
34 {
35 int i;
36 for (i = 0; i < 2; i++)
37 {
38 fd[i] = fd_safer (fd[i]);
39 if (fd[i] < 0)
40 {
41 int saved_errno = errno;
42 close (fd[1 - i]);
43 errno = saved_errno;
44 return -1;
45 }
46 }
47
48 return 0;
49 }
50
51 return -1;
52 }
53