php man page for pcntl_alarm

PCNTL_ALARM(3)								 1							    PCNTL_ALARM(3)

pcntl_alarm - Set an alarm clock for delivery of a signal

SYNOPSIS
       int pcntl_alarm (int  $seconds)

DESCRIPTION
	Creates  a  timer that will send a SIGALRM signal to the process after the given number of seconds. Any call to pcntl_alarm(3) will cancel
       any previously set alarm.

PARAMETERS
	      o $seconds
		- The number of seconds to wait. If $seconds is zero, no new alarm is created.

RETURN VALUES
	Returns the time in seconds that any previously scheduled alarm had remaining before it was to be delivered, or 0 if there was	no  previ-
       ously scheduled alarm.

PHP Documentation Group 													    PCNTL_ALARM(3)