(PHP 4, PHP 5)
sleep — Delay execution
Delays the program execution for the given number of seconds.
Halt time in seconds.
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.
If the specified number of seconds is negative, this function will generate a E_WARNING.
| 版本 | 说明 |
|---|---|
| 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. |
Example #1 sleep() example
This example will output (after 10 seconds)
<?php
// current time
echo date('h:i:s') . "
";
// sleep for 10 seconds
sleep(10);
// wake up !
echo date('h:i:s') . "
";
?>
05:31:23
05:31:33