dup-safer-flag.c

/* dup-safer-flag.c: Duplicate a file descriptor result, while avoiding
 * clobbering STD{IN,OUT,ERR}_FILENO, with specific flags.
 *
 * Copyright (C) 2001, 2004-2006, 2009-2012 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
 */

/* Written by Paul Eggert and Eric Blake.  */

#include <config.h>

/* Specification: */
#include "unistd-safer.h"
/* also here: */
#include "dup.h"

#include <fcntl.h>
#include <unistd.h>

/* Like dup, but do not return STDIN_FILENO, STDOUT_FILENO, or
 * STDERR_FILENO.  If FLAG contains O_CLOEXEC, behave like
 * fcntl(F_DUPFD_CLOEXEC) rather than fcntl(F_DUPFD).
 */
int
dup_safer_flag(int fd, int flag)
{
  return fcntl(fd, ((flag & O_CLOEXEC) ? F_DUPFD_CLOEXEC : F_DUPFD),
			   (STDERR_FILENO + 1));
}

/* EOF */