Test endianness in C

endianness.c

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

static inline uint8_t is_big_endian(void)
{
    const uint16_t endian = 256;
    return *(const uint8_t *)&endian;
}

int main(void)
{
    if (is_big_endian())
        printf("Big endian\n");
    else
        printf("Little endian\n");

    return 0;
}