dist/ntp/util/byteorder.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * This works on:
   5  *   Crays
   6  *   Conven
   7  *   sparc's
   8  *   Dec mip machines
   9  *   Dec alpha machines
  10  *   RS6000
  11  *   SGI's
  12  */
  13
  14 #include <stdio.h>
  15
  16 int
  17 main(
  18         int argc,
  19         char *argv[]
  20         )
  21 {
  22         int i;
  23         int big;
  24         union {
  25                 unsigned long l;
  26                 char c[sizeof(long)];
  27         } u;
  28
  29 #if defined(LONG8)
  30         u.l = (((long)0x08070605) << 32) | (long)0x04030201;
  31 #else
  32         u.l = 0x04030201;
  33 #endif
  34         if (sizeof(long) > 4) {
  35                 if (u.c[0] == 0x08) big = 1;
  36                 else                big = 0;
  37         } else {
  38                 if (u.c[0] == 0x04) big = 1;
  39                 else                big = 0;
  40         }
  41         for (i=0; i< sizeof(long); i++) {
  42                 if (big == 1 && (u.c[i] == (sizeof(long) - i))) {
  43                         continue;
  44                 } else if (big == 0 && (u.c[i] == (i+1))) {
  45                         continue;
  46                 } else {
  47                         big = -1;
  48                         break;
  49                 }
  50         }
  51
  52         if (big == 1) {
  53                 printf("XNTP_BIG_ENDIAN\n");
  54         } else if (big == 0) {
  55                 printf("XNTP_LITTLE_ENDIAN\n");
  56         }
  57         exit(0);
  58 }