stdio-common/tst-fileno.c

   1 /* Copyright (C) 1994, 1997, 2000 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22
  23 static int
  24 check (const char *name, FILE *stream, int fd)
  25 {
  26   int sfd = fileno (stream);
  27   printf ("(fileno (%s) = %d) %c= %d\n", name, sfd,
  28           sfd == fd ? '=' : '!', fd);
  29   return sfd != fd;
  30 }
  31
  32 int
  33 main (void)
  34 {
  35   return (check ("stdin", stdin, STDIN_FILENO) ||
  36           check ("stdout", stdout, STDOUT_FILENO) ||
  37           check ("stderr", stderr, STDERR_FILENO));
  38 }