The sleep keyword

sleep makes the process sleep for the number of seconds passed by the EXPRESSION seconds (integer).

It's not a good idea to mix alarm and sleep calls, as sleep is often implemented using alarm.

  sleep EXPRESSION

Examples

The code

print "Hello " . time . "\n";
sleep 5;
print "World! " . time . "\n";

returns the two strings with a leap of about 5 s:

Hello 1424262965
World! 1424262970