endian_check.c


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/* $Id$ */

#include <stdio.h>

// This pretty simple file checks if the system is LITTLE_ENDIAN or BIG_ENDIAN
//  it does that by putting a 1 and a 0 in an array, and read it out as one
//  number. If it is 1, it is LITTLE_ENDIAN, if it is 256, it is BIG_ENDIAN
//
// After that it outputs the contents of an include files (endian.h)
//  that says or TTD_LITTLE_ENDIAN, or TTD_BIG_ENDIAN. Makefile takes
//  care of the real writing to the file.

int main (int argc, char *argv[]) {
  unsigned char EndianTest[2] = { 1, 0 };
  int force_BE = 0, force_LE = 0;

  if (argc > 1 && strcmp(argv[1], "BE") == 0)
    force_BE = 1;
  if (argc > 1 && strcmp(argv[1], "LE") == 0)
    force_LE = 1;

  printf("#ifndef ENDIAN_H\n#define ENDIAN_H\n");

  if ( (*(short *) EndianTest == 1 && force_BE != 1) || force_LE == 1)
    printf("#define TTD_LITTLE_ENDIAN\n");
  else
    printf("#define TTD_BIG_ENDIAN\n");

  printf("#endif\n");

  return 0;
}