sleep - suspend execution for interval
unsigned int sleep(unsigned int seconds)
The current process is suspended from execution for the number of seconds
specified by the argument.
The routine is implemented by setting an alarm timer and pausing until it
occurs. The previous state of this timer is saved and restored. If the
sleep time exceeds the time to the expiration of the previous timer, the
process sleeps only until the signal would have occurred, and the signal
is sent 1 second later.