操作系统大端小端判断

 1 #include <stdio.h>
 2 
 3 union
 4 {
 5     short s;
 6     char c[sizeof(short)];
 7 }un;
 8 
 9 int main(int argc, char *argv[])
10 {
11     un.s = 0x0102;
12     
13     if(sizeof(short) == 2)
14     {
15         if(un.c[0] == 0x01 && un.c[1] == 0x02)
16         {
17             printf("big-endian\n"); /* 高位存低字节，低位存高字节 */
18         }
19         else if (un.c[0] == 0x02 && un.c[1] == 0x01)
20         {
21             printf("little-endian\n"); /* 低位存低字节，高位存高字节 */
22         }
23         else
24         {
25             printf("Unknow");
26         }
27     }
28     else
29     {
30         printf("sizeof(short) == %d\n", sizeof(short));
31     }
32     
33     return 0;
34 }