PHP WkHtmlToPdf/WkHtmlToImage 将网页直接转换成pdf和图片

function convert($type='pdf')
        {
            $filename=time();
            $url=$this->input->get("url");
            if($type=='pdf')
            {
                $filename="upload/tmp/".$filename.".pdf";
                exec("/home/phptool/wkhtmltopdf-i386 $url $filename");
                header('Content-Type: application/pdf');
            }
            elseif($type=='image')
            {
                $filename="upload/tmp/".$filename.".jpg";
                exec("/home/phptool/wkhtmltoimage-i386 $url $filename");
                header('Content-Type: image/jpeg');
            }
            header('Pragma: public');
            header('Expires: 0');
            header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
            header('Content-Transfer-Encoding: binary');
            header('Content-Length: '.filesize($filename));
            readfile("$filename");
        }