void print_hex(char hex) {
    char printed;

    if (hex < 10)
        printed = '0' + hex;
    else
        printed = 'a' + hex - 10;
    write(1, &printed, 1);
}

void print_memory(const void *addr, size_t size) {
    char* char_addr = (char*) addr;
    while (size--) {
        print_hex((*char_addr >> 4) & 0xF);
        print_hex((*char_addr) & 0xF);
        ++char_addr;
    }
}