php URL验证正则表达式

<?php 
$url = 'http://www.baidu.com/zongzi/oo.html'; 
$n = preg_match_all("/http:[\/]{2}[a-z]+[.]{1}[a-z\d\-]+[.]{1}[a-z\d]*[\/]*[A-Za-z\d]*[\/]*[A-Za-z\d]*[.]*html/",$url,$array); 
var_dump($array); 
?>