1 /* File descriptor validity check for posix_spawn file actions.
2 Copyright (C) 2000-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include "spawn_int.h"
20
21 #include <unistd.h>
22
23 bool
__spawn_valid_fd(int fd)24 __spawn_valid_fd (int fd)
25 {
26 long maxfd = __sysconf (_SC_OPEN_MAX);
27 return __glibc_likely (fd >= 0)
28 && (__glibc_unlikely (maxfd < 0) /* No limit set. */
29 || __glibc_likely (fd < maxfd));
30 }
31