IDM with PHP CURL

<?php
error_reporting(0);
function download($url)
{
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_PROGRESSFUNCTION, 'callback');
    curl_setopt($ch, CURLOPT_NOPROGRESS, false);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
    $html = curl_exec($ch);
    curl_close($ch);
    return $html;
}


function callback($jembut,$download_size, $downloaded, $upload_size, $uploaded)
{
    if( $downloaded != 0 ){
        show_status($downloaded, $download_size, 20);
    }
}

function show_status($done, $total, $size=30) {
    $total = str_replace("-", "", $total);
    static $start_time;
    if($done > $total) return;

    if(empty($start_time)) $start_time=time();
    $now = time();
    $perc=(double)($done/$total);
    $bar=floor($perc*$size);
    $status_bar="\r[";
    $status_bar.=str_repeat("=", $bar);
    if($bar<$size){
        $status_bar.=">";
        $status_bar.=str_repeat(" ", $size-$bar);
    } else {
        $status_bar.="=";
    }
    $disp=number_format($perc*100, 0);
    $status_bar.="] $disp%  ".formatSizeUnits($done)." / ".formatSizeUnits($total);
    $rate = ($now-$start_time)/$done;
    $left = $total - $done;
    $eta = round($rate * $left, 2);
    $elapsed = $now - $start_time;
    $status_bar.= " Menunggu : ".number_format($eta)." detik.  Time left : ".number_format($elapsed)." sec.";
    echo "$status_bar  ";
    flush();
    if($done == $total) {
        echo "\n";
    }
}
function formatSizeUnits($bytes)
    {
        if ($bytes >= 1073741824)
        {
            $bytes = number_format($bytes / 1073741824, 2) . ' GB';
        }
        elseif ($bytes >= 1048576)
        {
            $bytes = number_format($bytes / 1048576, 2) . ' MB';
        }
        elseif ($bytes >= 1024)
        {
            $bytes = number_format($bytes / 1024, 2) . ' kB';
        }
        elseif ($bytes > 1)
        {
            $bytes = $bytes . ' bytes';
        }
        elseif ($bytes == 1)
        {
            $bytes = $bytes . ' byte';
        }
        else
        {
            $bytes = '0 bytes';
        }

        return $bytes;
}

download("http://google.com");