(PHP 3, PHP 4, PHP 5)
Delays program execution for the given number of micro seconds.
micro_seconds
Halt time in micro seconds. A micro second is one millionth of a second.
无返回值。
例 1. usleep() example
<?php // Current time echo date('h:i:s') . "\n"; // wait for 2 seconds usleep(2000000); // back! echo date('h:i:s') . "\n"; ?>
上例将输出：
11:13:28 11:13:30
