大端与小端

#include <stdio.h>

int main()
{
union
{
short s;
char c[sizeof(short)];
}un;

un.s = 0x0102;

if(sizeof(short) == 2)
{
if(un.c[0] == 1 && un.c[1] == 2)
printf("big-endian\n");
else if(un.c[0] == 2 && un.c[1] == 1)
printf("little-endian\n");
else
printf("unknown\n");
}

printf("sizoef(short) = %d\n",sizeof(short));
return 0;
}