怎么检查页面URL中是否有某个字符串

如何检查页面URL中是否有某个字符串？
鉴于安全，想获取本页面的url，检查里面是否有“script”这个字符串，若有则禁止访问或退出。该如何实现？

[解决办法]
strstr strpos
[解决办法]
you should have a html parser...
[解决办法]
you should have a html parser. I suppose there are such php version in the wild.
[解决办法]

PHP code

  function curPageURL(){    $pageURL = 'http';    if ($_SERVER["HTTPS"] == "on")    {        $pageURL .= "s";    }    $pageURL .= "://";    if ($_SERVER["SERVER_PORT"] != "80")    {        $pageURL .= $_SERVER["SERVER_NAME"] . ":" . $_SERVER["SERVER_PORT"] . $_SERVER["REQUEST_URI"];    }    else    {        $pageURL .= $_SERVER["SERVER_NAME"] . $_SERVER["REQUEST_URI"];    }    return $pageURL;}