stdio-common/tst-fileno.c

   1 /* Copyright (C) 1994-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library 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 GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21
  22 static int
  23 check (const char *name, FILE *stream, int fd)
  24 {
  25   int sfd = fileno (stream);
  26   printf ("(fileno (%s) = %d) %c= %d\n", name, sfd,
  27           sfd == fd ? '=' : '!', fd);
  28   return sfd != fd;
  29 }
  30
  31 int
  32 main (void)
  33 {
  34   return (check ("stdin", stdin, STDIN_FILENO) ||
  35           check ("stdout", stdout, STDOUT_FILENO) ||
  36           check ("stderr", stderr, STDERR_FILENO));
  37 }