How to confirm whether a computer is Big-endian or Little-endian?

Let's say we're using a 32-bit machine.

If it's little endian, then X is arranged in memory.

      High memory       ---->  +----+----+----+----+  |0x01|0x00|0x00|0x00|  +----+----+----+----+  A  |  &x SO (char*) (*x) = = 1

If it's big endian, it's going to be like this.

      High memory       ---->  +----+----+----+----+  |0x00|0x00|0x00|0x01|  +----+----+----+----+  A  |  &x SO (char*) (*x) = = 0

#include <stdio.h> #include <stdint.h>int is_big_endian (void) {union {uint32_t I;char c[4];} e = {0x10000000} ; return e.c[0];} int main (void) {printf ("System is%s-endian.\n", Is_big_endian ()? "Big": "little"); return 0;}

How to confirm whether a computer is Big-endian or Little-endian?