判断host大小端

1 #include     "unp.h"

2 int
3 main(int argc, char **argv)
4 {
5     union {
6         short   s;
7         char    c[sizeof(short)];
8     } un;

9     un.s = 0x0102;
10     printf("%s: ", CPU_VENDOR_OS);
11     if (sizeof(short) == 2) {
12         if (un.c[0] == 1 && un.c[1] == 2)
13             printf("big-endian\n");
14         else if (un.c[0] == 2 && un.c[1] == 1)
15             printf("little-endian\n");
16         else
17             printf("unknown\n");
18     } else
19         printf("sizeof(short) = %d\n", sizeof(short));

20     exit(0);
21 }