| 1 | /* Invoke pipe, but avoid some glitches. |
| 2 | Copyright (C) 2005-2006, 2009-2020 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 | } |