php获得网站在百度搜索引擎中的收录量方法

<?php
function baiduSl($url){
 $baidu="http://www.baidu.com/s?wd=site:".$url;
 $site=file_get_contents($baidu);
 ereg("该网站共有(.*)个网页被百度收录", $site,$count);
 $count=str_replace("该网站共有","",$count);
 $count=str_replace("个网页被百度收录","",$count);
 $count=str_replace(",","",$count);
 $count=str_replace(" ","",$count);
 return strip_tags($count[0]);