php实现递归抓取网页类实例

本文实例讲述了php实现递归抓取网页类的方法。分享给大家供大家参考。具体如下：

<?phpclass 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; }}?>

希望本文所述对大家的php程序设计有所帮助。