kc3-lang/gnulib/lib/fd-safer.c

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• Hash : 281b825e
  Author :
  Date : 2018-01-01T00:57:25
  

  maint: Run 'make update-copyright'
  

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• lib/fd-safer.c

• /* Return a safer copy of a file descriptor.
  
     Copyright (C) 2005-2006, 2009-2018 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 <https://www.gnu.org/licenses/>.  */
  
  /* Written by Paul Eggert.  */
  
  #include <config.h>
  
  #include "unistd-safer.h"
  
  #include <errno.h>
  #include <unistd.h>
  
  /* Return FD, unless FD would be a copy of standard input, output, or
     error; in that case, return a duplicate of FD, closing FD.  On
     failure to duplicate, close FD, set errno, and return -1.  Preserve
     errno if FD is negative, so that the caller can always inspect
     errno when the returned value is negative.
  
     This function is usefully wrapped around functions that return file
     descriptors, e.g., fd_safer (open ("file", O_RDONLY)).  */
  
  int
  fd_safer (int fd)
  {
    if (STDIN_FILENO <= fd && fd <= STDERR_FILENO)
      {
        int f = dup_safer (fd);
        int e = errno;
        close (fd);
        errno = e;
        fd = f;
      }
  
    return fd;
  }
  

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