1/* Invoke pipe, but avoid some glitches. 2 Copyright (C) 2005, 2006 Free Software Foundation, Inc. 3 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. 8 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. 13 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ 17 18/* Written by Jim Meyering. */ 19 20#include <config.h> 21 22#include "unistd-safer.h" 23 24#include <unistd.h> 25#include <errno.h> 26 27/* Like pipe, but ensure that neither of the file descriptors is 28 STDIN_FILENO, STDOUT_FILENO, or STDERR_FILENO. Fail with ENOSYS on 29 platforms that lack pipe. */ 30 31int 32pipe_safer (int fd[2]) 33{ 34#if HAVE_PIPE 35 if (pipe (fd) == 0) 36 { 37 int i; 38 for (i = 0; i < 2; i++) 39 { 40 fd[i] = fd_safer (fd[i]); 41 if (fd[i] < 0) 42 { 43 int e = errno; 44 close (fd[1 - i]); 45 errno = e; 46 return -1; 47 } 48 } 49 50 return 0; 51 } 52#else 53 errno = ENOSYS; 54#endif 55 56 return -1; 57} 58