(PHP 4, PHP 5, PHP 7, PHP 8)
usleep — Delay execution in microseconds
$microseconds
): voidDelays program execution for the given number of microseconds.
microseconds
Halt time in microseconds. A microsecond is one millionth of a second.
Note: Values larger than
1000000
(i.e. sleeping for more than a second) may not be supported by the operating system. Use sleep() instead.
Note: The sleep may be lengthened slightly (i.e. may be longer than
microseconds
) by any system activity or by the time spent processing the call or by the granularity of system timers.
No value is returned.
Example #1 usleep() example
<?php
// Current time
echo (new DateTime('now'))->format('H:i:s.v'), "\n";
// wait for 2 milliseconds
usleep(2000);
// back!
echo (new DateTime('now'))->format('H:i:s.v'), "\n";
// wait for 30 milliseconds
usleep(30000);
// back again!
echo (new DateTime('now'))->format('H:i:s.v'), "\n";
?>
The above example will output:
11:13:28.005 11:13:28.007 11:13:28.037