1 | /* Invoke pipe, but avoid some glitches. |
2 | Copyright (C) 2005-2006, 2009-2019 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 |
31 | pipe_safer (int fd[2]) |
32 | { |
33 | #if HAVE_PIPE |
34 | if (pipe (fd) == 0) |
35 | { |
36 | int i; |
37 | for (i = 0; i < 2; i++) |
38 | { |
39 | fd[i] = fd_safer (fd[i]); |
40 | if (fd[i] < 0) |
41 | { |
42 | int e = errno; |
43 | close (fd[1 - i]); |
44 | errno = e; |
45 | return -1; |
46 | } |
47 | } |
48 | |
49 | return 0; |
50 | } |
51 | #else |
52 | errno = ENOSYS; |
53 | #endif |
54 | |
55 | return -1; |
56 | } |
57 | |