xref: /netbsd-src/external/gpl2/xcvs/dist/lib/pipe-safer.c (revision 5a6c14c844c4c665da5632061aebde7bb2cb5766)
1 /* Invoke pipe, but avoid some glitches.
2    Copyright (C) 2005 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 #include <sys/cdefs.h>
18 __RCSID("$NetBSD: pipe-safer.c,v 1.2 2016/05/17 14:00:09 christos Exp $");
19 
20 
21 /* Written by Jim Meyering.  */
22 
23 #ifdef HAVE_CONFIG_H
24 # include <config.h>
25 #endif
26 
27 #include "unistd-safer.h"
28 
29 #include <unistd.h>
30 
31 /* Like pipe, but ensure that neither of the file descriptors is
32    STDIN_FILENO, STDOUT_FILENO, or STDERR_FILENO.  */
33 
34 int
pipe_safer(int fd[2])35 pipe_safer (int fd[2])
36 {
37   int fail = pipe (fd);
38   if (fail)
39     return fail;
40 
41   {
42     int i;
43     for (i = 0; i < 2; i++)
44       {
45 	int f = fd_safer (fd[i]);
46 	if (f < 0)
47 	  return -1;
48 	fd[i] = f;
49       }
50   }
51 
52   return 0;
53 }
54