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      1 /* Invoke pipe2, but avoid some glitches.
      2    Copyright (C) 2005-2006, 2009-2012 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 3 of the License, or
      7    (at your option) 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, see <http://www.gnu.org/licenses/>.  */
     16 
     17 /* Written by Eric Blake.  */
     18 
     19 #include <config.h>
     20 
     21 /* Specification.  */
     22 #include "unistd-safer.h"
     23 
     24 #include <unistd.h>
     25 #include <errno.h>
     26 
     27 /* Like pipe2, but ensure that neither of the file descriptors is
     28    STDIN_FILENO, STDOUT_FILENO, or STDERR_FILENO.  */
     29 
     30 int
     31 pipe2_safer (int fd[2], int flags)
     32 {
     33   /* This is a generalization of the pipe_safer implementation.  */
     34   if (pipe2 (fd, flags) == 0)
     35     {
     36       int i;
     37       for (i = 0; i < 2; i++)
     38         {
     39           fd[i] = fd_safer_flag (fd[i], flags);
     40           if (fd[i] < 0)
     41             {
     42               int e = errno;
     43               close (fd[1 - i]);
     44               errno = e;
     45               return -1;
     46             }
     47         }
     48 
     49       return 0;
     50     }
     51   return -1;
     52 }
     53