判断主机是大端还是小段-C语言

#include <stdio.h>union tmp{    int nn;    char cc;};int main(){    union tmp test;    test.nn = 0x12345678;    if(test.cc==0x12)    {        printf("大端\n");    }    else if(test.cc ==0x78)    {        printf("小端\n");    }    return 0;}

0x12345678 大端：12345678 小端：87654321