Digital clock in C++

#include <iostream>
using namespace std;
#include <time.h>
int main()
{
    time_t s, val = 1;
    struct tm* current_time;

    s = time(NULL);

    current_time = localtime(&s);

    cout<<current_time->tm_hour<<":"<<current_time->tm_min<<":"<<current_time->tm_sec;

    return 0;
}