C program to detect machine endianness

endian.c

#include <stdint.h>
#include <stdio.h>

int main(void)
{
    union { uint8_t bytes[4]; uint32_t value; } x = { .bytes = {0x11, 0x22, 0x33, 0x44} };
    switch (x.value) {
        case 0x11223344:
            printf("big\n");
            return 0;
        case 0x44332211:
            printf("little\n");
            return 0;
        case 0x22114433:
            printf("middle\n");
            return 0;
        default:
            printf("unknown\n");
            return 1;
    }
}