contrib/ntp/util/byteorder.c

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