PHP Manual: Delay execution

Description

int sleep ( int $seconds )

Delays the program execution for the given number of seconds.

Parameters

seconds: Halt time in seconds.

Return Values

Returns zero on success, or FALSE on error.

If the call was interrupted by a signal, sleep returns a non-zero value. On Windows, this value will always be 192 (the value of the WAIT_IO_COMPLETION constant within the Windows API). On other platforms, the return value will be the number of seconds left to sleep.

Errors/Exceptions

If the specified number of seconds is negative, this function will generate a E_WARNING.

Changelog

Version	Description
5.3.4	Before PHP 5.3.4, on Windows, sleep always returns `NULL` when sleep has occurred, regardless of whether the sleep was interrupted or not.

Examples

Example #1 sleep example


<?php

// current time
echo date('h:i:s') . "\n";

// sleep for 10 seconds
sleep(10);

// wake up !
echo date('h:i:s') . "\n";

?>

This example will output (after 10 seconds)

05:31:23
05:31:33

sleep