[C] Byte ordering check

   
#include <stdio.h>

int main(){

 int i = 0x1213456789;

 char* p = (char *)&i;

 printf("%x\n", *p);

 if (*p == (char)0x00000089)

 printf("little endian\n");

 else

 printf("big endian\n");

 return 0;

}