Wait/Pause an amount of seconds in C

easy:

while( true )
{
    // your stuff
    sleep( 10 ); // sleeping for 10 seconds
};

On Windows, the function to do this is Sleep, which takes the amount of milliseconds you want to sleep. To use Sleep, you need to include windows.h.

On POSIX-Systems, the function sleep (from unistd.h) accomplishes this:

   unsigned int sleep(unsigned int seconds);

   DESCRIPTION
          sleep()  makes  the  calling thread sleep until
          seconds seconds have elapsed or a signal arrives which is not ignored.

If it is interrupted by a signal, the remaining time to sleep is returned. If you use signals, a more robust solution would be:

 unsigned int time_to_sleep = 10; // sleep 10 seconds
 while(time_to_sleep)
     time_to_sleep = sleep(time_to_sleep);

This is of course assuming your signal-handlers only take a negligible amount of time. (Otherwise, this will delay the main program longer than intended)