1 /* Invoke pipe, but avoid some glitches.
2 Copyright (C) 2005, 2006 Free Software Foundation, Inc.
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 2, or (at your option)
7 any later version.
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.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
18 /* Written by Jim Meyering. */
20 #include <config.h>
22 #include "unistd-safer.h"
24 #include <unistd.h>
25 #include <errno.h>
27 /* Like pipe, but ensure that neither of the file descriptors is
28 STDIN_FILENO, STDOUT_FILENO, or STDERR_FILENO. Fail with ENOSYS on
29 platforms that lack pipe. */
31 int
32 pipe_safer (int fd[2])
33 {
34 #if HAVE_PIPE
35 if (pipe (fd) == 0)
36 {
37 int i;
38 for (i = 0; i < 2; i++)
39 {
40 fd[i] = fd_safer (fd[i]);
41 if (fd[i] < 0)
42 {
43 int e = errno;
44 close (fd[1 - i]);
45 errno = e;
46 return -1;
47 }
48 }
50 return 0;
51 }
52 #else
53 errno = ENOSYS;
54 #endif
56 return -1;
57 }