{
    struct stat st;

    /* The following makes sure that file descriptors 0 (stdin), 1
       (stdout) and 2 (stderr) will not be "reused", because if
       e.g. file descriptor 2 would be reused when opening a file, a
       write to stderr would write to that file and most likely
       corrupt it. */
    if ((fstat (0, &st) == -1 && open ("/dev/null", O_RDONLY) == -1) ||
        (fstat (1, &st) == -1 && open ("/dev/null", O_WRONLY) == -1) ||
        (fstat (2, &st) == -1 && open ("/dev/null", O_WRONLY) == -1))
      {
        fprintf(error_stream, "%s: error: cannot open '/dev/null'\n",
                progname);
        return EXIT_FAILURE;
      }
  }