C語言 - how to check big or little endian

Q: big endian vs little endian, how to check ?

sample code:
int main(void)
{
    short int a = 0x1234;
    char *p = (char *)&a;
   
    printf("p=%#hhx\n",*p);

    if(*p == 0x34)
        printf("Little endian \n");
    else if(*p == 0x12)
        printf("Big endian \n");
    else
        printf("Unknow endian \n");

    return 0;
}