测试处理器是大端序还是小端序(Big Endian or Little Endian)

/*
 * How can I determine whether a machine'sbyte orderis big-endian or little-endian?
 * */

#include <stdio.h>

int main(int argc, char const *argv[])
{
    /* method 1 */
    int x = 1;
    if(*(char *)&x == 1)
        printf("little-endian\n");
    else
        printf("big-endian\n");

    /* method 2 */
    {
        union {
            int i;
            char c[sizeof(int)];
        } unx;

        unx.i = 1;
        if(unx.c[0] == 1)
            printf("little-endian\n");
        else
            printf("big-endian\n");
    }

    return 0;
}