coreutils/lib/cloexec.c

62 lines
1.5 KiB
C

/* closexec.c - set or clear the close-on-exec descriptor flag
Copyright (C) 1991, 2004 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
The code is taken from glibc/manual/llio.texi */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include "cloexec.h"
#include <unistd.h>
#include <fcntl.h>
#ifndef FD_CLOEXEC
# define FD_CLOEXEC 1
#endif
/* Set the `FD_CLOEXEC' flag of DESC if VALUE is true,
or clear the flag if VALUE is false.
Return 0 on success, or -1 on error with `errno' set. */
int
set_cloexec_flag (int desc, bool value)
{
#if defined F_GETFD && defined F_SETFD
int flags = fcntl (desc, F_GETFD, 0);
if (0 <= flags)
{
int newflags = (value ? flags | FD_CLOEXEC : flags & ~FD_CLOEXEC);
if (flags == newflags
|| fcntl (desc, F_SETFD, newflags) != -1)
return 0;
}
return -1;
#else
return 0;
#endif
}