php 利用curl_multi_int 批量下载图片

<?phpclass curl_multi{  private $url_list=array();  private $curl_setopt=array(  'CURLOPT_RETURNTRANSFER' => 1,//结果返回给变量  'CURLOPT_HEADER' => 0,//是否需要返回HTTP头  'CURLOPT_NOBODY' => 0,//是否需要返回的内容  'CURLOPT_FOLLOWLOCATION' => 0,//自动跟踪  'CURLOPT_TIMEOUT' => 6//超时时间(s)  );  function __construct($seconds=30){  set_time_limit($seconds);  }  /*  * 设置网址  * @list 数组  */  public function setUrlList($list=array()){  $this->url_list=$list;  }  /*  * 设置参数  * @cutPot array  */  public function setOpt($cutPot){  $this->curl_setopt=$cutPot+$this->curl_setopt;  }  /*  * 执行  * @return array  */  public function execute(){  $mh=curl_multi_init();  foreach($this->url_list as $i=>$url){  $conn[$i]=curl_init($url);  foreach($this->curl_setopt as $key => $val){  curl_setopt($conn[$i],preg_replace('/(CURLOPT_w{1,})/ie','$0',$key),$val);  }  curl_multi_add_handle($mh,$conn[$i]);  }  $active=false;  do{  $mrc=curl_multi_exec($mh,$active);  }while($mrc == CURLM_CALL_MULTI_PERFORM);  while($active and $mrc == CURLM_OK){  if(curl_multi_select($mh) != -1){  do{  $mrc=curl_multi_exec($mh,$active);  }while($mrc == CURLM_CALL_MULTI_PERFORM);  }  }  $res=array();  foreach($this->url_list as $i => $url){  $res[$i]=curl_multi_getcontent($conn[$i]);  curl_close($conn[$i]);  curl_multi_remove_handle($mh,$conn[$i]);//释放资源  }  curl_multi_close($mh);  return $res;  }}