#include <stdio.h>

 union endian_u

 {

     /*最大成员的长度就是联合成员的长度。联合可以在定义时直接进行初始化，但这个初始化必须是联合第一个成员的类型，所以把unsigned short sval放在第一个成员的原因*/

     unsigned short sval;

     unsigned char cval[];

 };

 int main(int argc, char *argv[])

 {

     char *info = "unknow endian";

     union endian_u t = { 0x1234 };

     if (t.cval[] == 0x12 && t.cval[] == 0x34)

         info = "big-endian";

     else if (t.cval[] == 0x34 && t.cval[] == 0x12)

         info = "little-endian";

     printf("host is %s.\n", info);

     return ;

 }