php文件的跨域上传方式之一 CURL

 if(!empty($_FILES['filename']['name']))        {            $p = current($_FILES);              $picturedata = fread(fopen($p['tmp_name'], "r"), $p['size']);            $varname = 'filename';            $name = $_FILES['filename']['name'];            $type =  $_FILES['filename']['type'];            $key = "$varname\"; filename=\"$name\r\nContent-Type: $type\r\nAccept: \"";            $fields[$key] = $picturedata;                    $ch = curl_init();            curl_setopt($ch, CURLOPT_URL,"http://192.168.18.200:84/pic.php");            curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST" );            curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);            $s = curl_exec ($ch);                curl_close ($ch);                echo $s;         }