파일 다운로드 함수(멀티 이어받기/속도제한)

function fDown($file,$name,$downview,$speed,$limit)// 경로, 원파일명, 다운/보임, 다운속도, 속도제한여부
{
    if(!file_exists($file))
        die('File not exist!');
    $size = filesize($file);
    $name = rawurldecode($name);

    if (ereg('Opera(/| )([0-9].[0-9]{1,2})', $_SERVER['HTTP_USER_AGENT']))
        $UserBrowser = "Opera";
    elseif (ereg('MSIE ([0-9].[0-9]{1,2})', $_SERVER['HTTP_USER_AGENT']))
        $UserBrowser = "IE";
    else
        $UserBrowser = '';

    // 브라우저 정의
    $mime_type = ($UserBrowser == 'IE' || $UserBrowser == 'Opera')? 'application/octetstream' : 'application/octet-stream';
    @ob_end_clean(); // decrease cpu usage extreme
    Header('Content-Type: ' . $mime_type);
    Header('Content-Disposition: $downview; filename="'.$name.'"');
    Header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
    Header('Accept-Ranges: bytes');
    Header("Cache-control: private");
    Header('Pragma: private');

    //  multipart-download and resume-download
    if(isset($_SERVER['HTTP_RANGE']))
    {
        list($a, $range) = explode("=",$_SERVER['HTTP_RANGE']);
        str_replace($range, "-", $range);
        $size2 = $size-1;
        $new_length = $size-$range;
        Header("HTTP/1.1 206 Partial Content");
        Header("Content-Length: $new_length");
        Header("Content-Range: bytes $range$size2/$size");
    } else {
        $size2=$size-1;
        Header("Content-Length: ".$size);
    }
    $chunksize = 1*(1024*$speed); // 속도제한값
    $this->bytes_send = 0;
    if ($file = fopen($file, 'rb'))
    {
        if(isset($_SERVER['HTTP_RANGE']))
            fseek($file, $range);
        while(!feof($file) and (connection_status()==0))
        {
            $buffer = fread($file, $chunksize);
            print($buffer);//echo($buffer); // is also possible
            flush();
            $this->bytes_send += strlen($buffer);
            if($limit) sleep(1); // 다운로드 속도제한
        }
        fclose($file);
    } else
        die('Error can not open file!!');
    if(isset($new_length))
        $size = $new_length;
    die();
    Header("Connection: close");
}