#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int last = 0, sec = 0, delta = 5; // sec

void p_sec()
{
    sec = (int)( clock()/CLOCKS_PER_SEC ); // get program time/ convert to seconds as integer
    if ( sec - last == delta )
    {
        printf("timer %d\n",sec);
        last = sec;
    }
}

int main()
{
    printf("timer start!\n");
    while ( sec < 60 )
    {
        p_sec();
    }
    return 0;
}