CPU大小端判断

 1  1 #include<stdio.h>
 2   2 union Data{
 3   3         char ch;
 4   4         short data;
 5   5 };
 6   6 union Data u_Data;
 7   7 //judege cpu little_endian or big_endian
 8   8 int main()
 9   9         {
10  10           char *p;
11  11           char i=1;
12  12           p=&i;
13  13           u_Data.data=0x0102;
14  14           if(*p)
15  15             {
16  16               printf("cpu is little endian\n");
17  17             }
18  18           else printf("cpu is big endian\n");
19  19           if(sizeof(short)==2)
20  20             {
21  21               if(u_Data.ch==0x02)
22  22                  {
23  23                     printf("cpu is little endian\n");
24  24                  }
25  25               else if(u_Data.ch==0x01)
26  26                  {
27  27                     printf("cpu is big endian\n");
28  28                  }
29  29             }
30  30           return 0;
31  31         }