sleep

(PHP 4, PHP 5, PHP 7, PHP 8)

sleep — Delay execution

Description

sleep(int $seconds): int

Delays the program execution for the given number of seconds.

Note:

In order to delay program execution for a fraction of a second, use usleep() as the sleep() function expects an int. For example, sleep(0.25) will pause program execution for 0 seconds.

Parameters

seconds

Halt time in seconds (must be greater than or equal to 0).

Return Values

Returns zero on success.

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 throw a ValueError.

Changelog

VersionDescription
8.0.0The function throws a ValueError on negative seconds; previously, an E_WARNING was raised instead, and the function returned false.

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

See Also