1 /* closexec.c - set or clear the close-on-exec descriptor flag
2 Copyright (C) 1991, 2004 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 The code is taken from glibc/manual/llio.texi */
20 #if HAVE_CONFIG_H
21 # include <config.h>
22 #endif
24 #include "cloexec.h"
26 #if HAVE_UNISTD_H
27 # include <unistd.h>
28 #endif
30 #if HAVE_FCNTL_H
31 # include <fcntl.h>
32 #endif
34 #ifndef FD_CLOEXEC
35 # define FD_CLOEXEC 1
36 #endif
38 /* Set the `FD_CLOEXEC' flag of DESC if VALUE is true,
39 or clear the flag if VALUE is false.
40 Return true on success, or false on error with `errno' set. */
42 bool
43 set_cloexec_flag (int desc, bool value)
44 {
45 #if defined F_GETFD && defined F_SETFD
47 int flags = fcntl (desc, F_GETFD, 0);
48 int newflags;
50 if (flags < 0)
51 return false;
53 newflags = (value ? flags | FD_CLOEXEC : flags & ~FD_CLOEXEC);
55 return (flags == newflags
56 || fcntl (desc, F_SETFD, newflags) != -1);
58 #else
60 return true;
62 #endif
63 }