详解大端模式和小端模式

http://blog.csdn.net/ce123_zhouwei/article/details/6971544


一个小程序判断机器的大小端

1. #include <stdio.h>
   
2. 
   
3. int main(void)
   
4. {
   
5.     union {
   
6.         int s;
   
7.         char c[sizeof(int)];
   
8.     }un;
   
9.     un.s = 0x12345678;
   
10.     
    
11.     printf("%p,%p,%p,%p\n",un.c[0],un.c[1],un.c[2],un.c[3]);
    
12.     printf("%p,%p,%p,%p\n",&un.c[0],&un.c[1],&un.c[2],&un.c[3]);
    
13. # if __BYTE_ORDER == __LITTLE_ENDIAN
    
14.     printf("little endian\n");
    
15. # elif __BYTE_ORDER == __BIG_ENDIAN
    
16.     printf("big endian\n");
    
17. # else
    
18.     # error "__BYTE_ORDER neither __LITTLE_ENDIAN nor __BIG_ENDIAN!!!"
    
19. # endif
    
20.     return 0;
    
21. }