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/* Invoke pipe, but avoid some glitches. 
   Copyright (C) 2005-2006, 2009-2013 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 Jim Meyering.  */ 
 
#include <config.h> 
 
#include "unistd-safer.h" 
 
#include <unistd.h> 
#include <errno.h> 
 
/* Like pipe, but ensure that neither of the file descriptors is 
   STDIN_FILENO, STDOUT_FILENO, or STDERR_FILENO.  Fail with ENOSYS on 
   platforms that lack pipe.  */ 
 
int 
pipe_safer (int fd[2]) 
{ 
#if HAVE_PIPE 
  if (pipe (fd) == 0) 
    { 
      int i; 
      for (i = 0; i < 2; i++) 
        { 
          fd[i] = fd_safer (fd[i]); 
          if (fd[i] < 0) 
            { 
              int e = errno; 
              close (fd[1 - i]); 
              errno = e; 
              return -1; 
            } 
        } 
 
      return 0; 
    } 
#else 
  errno = ENOSYS; 
#endif 
 
  return -1; 
}