一个php递归抓取网页的类

一个php递归抓取网页的类

<?php
class crawler{
	private $_depth=5;
	private $_urls=array();
	
	
	function extract_links($url)
	{
		if(!$this->_started){
			$this->_started=1;
			$curr_depth=0;
		}else{
			$curr_depth++;
		}
		if($curr_depth<$this->_depth)
		{
			$data=file_get_contents($url);
			if(preg_match_all('/((?:http|https)://(?:www.)*(?:[a-zA-Z0-9_-]{1,15}.+[a-zA-Z0-9_]{1,}){1,}(?:[a-zA-Z0-9_/.-?&:%,!;]*))/',$data,$urls12))
			{
				foreach($urls12[0] as $k=>$v){
					$check=get_headers($v,1);
					if(strstr($v,$url) && $check[0]=='HTTP/1.1 200 OK' && !array_search($v,$this->_urls) && $curr_depth<$this->_depth){
						$this->_urls[]=$v;
						$this->extract_links($v);
					}
				}
			}
		}
		return $this->_urls;
	}
}
?>