1/* Invoke dup, but avoid some glitches. 2 3 Copyright (C) 2001, 2004, 2005, 2006 Free Software Foundation, Inc. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program 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 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 17 18/* Written by Paul Eggert. */ 19 20#include <config.h> 21 22#include "unistd-safer.h" 23 24#include <fcntl.h> 25 26#include <unistd.h> 27#ifndef STDERR_FILENO 28# define STDERR_FILENO 2 29#endif 30 31/* Like dup, but do not return STDIN_FILENO, STDOUT_FILENO, or 32 STDERR_FILENO. */ 33 34int 35dup_safer (int fd) 36{ 37#if defined F_DUPFD && !defined FCHDIR_REPLACEMENT 38 return fcntl (fd, F_DUPFD, STDERR_FILENO + 1); 39#else 40 /* fd_safer calls us back, but eventually the recursion unwinds and 41 does the right thing. */ 42 return fd_safer (dup (fd)); 43#endif 44} 45