sysdeps/generic/det_endian.c

   1 /* Determine the "endianness" of the CPU.
   2    Copyright (C) 1991, 1992, 1997 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Torbjorn Granlund (tege@sics.se).
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <stdio.h>
  22
  23 main ()
  24 {
  25   unsigned long int i;
  26
  27   if (sizeof (i) != 4)
  28     puts ("#error \"Not a 32-bit machine!\"");
  29
  30   i = (((((('4' << 8) + '3') << 8) + '2') << 8) + '1');
  31
  32   printf ("#define __BYTE_ORDER %.4s\n", (char *) &i);
  33
  34   exit (0);
  35 }