Question

I would like to subtract current_time with previously_saved_time and check if it’s bigger then wait_time. wait time should be an int. Can someone give me a simple example? In other words:

if ((current_time - previously_saved_time) > wait_time) {
    do something;
}

Answer 1

What you have is exactly what you need, other than replacing do something with some actual code.

For example, this program waits three seconds:

#include <time.h>

int main(void) {
    time_t base = time (0);
    time_t now = base;
    while (now - base < 3)
        now = time (0);
    return 0;
}

It simply loops in the while statement until the difference between the base time and the current time is three or more (there are almost certainly better ways to wait for N seconds, this is just meant to illustrate the calculation).