PHP - Downloading Remote Files

Hello everyone.
I have a problem with some of my php script.

I have some php code that downloads a remote file and directly outputs it to the user. It works and all, it's just that when I do it on my Ubuntu LAMP server, downloading a file takes up a lot of ram. On my Windows WAMP server it works correctly and doesn't use up so much ram. Is this a problem with my code, or is it a server configuration?

Below is the code I use to download the file.
Code: [Select]

public function output_file($file, $name, $mime_type='', $size)
   {
   session_write_close();
    /*
    This function takes a path to a file to output ($file),
    the filename that the browser will see ($name) and
    the MIME type of the file ($mime_type, optional).
   
    If you want to do something on download abort/finish,
    register_shutdown_function('function_name');
    */
    if(is_readable($file)) die('File not found or inaccessible!');
    /*
    $size = $size;
    $name = rawurldecode($name); */
   
    /* Figure out the MIME type (if not specified) */
    $known_mime_types=array(
      "pdf" => "application/pdf",
      "txt" => "text/plain",
      "html" => "text/html",
      "htm" => "text/html",
      "exe" => "application/octet-stream",
      "zip" => "application/zip",
      "doc" => "application/msword",
      "xls" => "application/vnd.ms-excel",
      "ppt" => "application/vnd.ms-powerpoint",
      "gif" => "image/gif",
      "png" => "image/png",
      "jpeg"=> "image/jpg",
      "jpg" =>  "image/jpg",
      "php" => "text/plain"
    );
   
    if($mime_type==''){
       $file_extension = strtolower(substr(strrchr($file,"."),1));
       if(array_key_exists($file_extension, $known_mime_types)){
         $mime_type=$known_mime_types[$file_extension];
       } else {
         $mime_type="application/x-rar-compressed";
       };
    };
   
    @ob_end_clean(); //turn off output buffering to decrease cpu usage
   
    // required for IE, otherwise Content-Disposition may be ignored
    if(ini_get('zlib.output_compression'))
     ini_set('zlib.output_compression', 'Off');
   
    header('Content-Type: ' . $mime_type);
    header('Content-Disposition: attachment; filename="'.$name.'"');
    header("Content-Transfer-Encoding: binary");
    header('Accept-Ranges: bytes');
   
    /* The three lines below basically make the
      download non-cacheable */
    header("Cache-control: no-cache");
    //header('Pragma: private');
   // header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
   
    // multipart-download and download resuming support
    if(isset($_SERVER['HTTP_RANGE']))
    {
      list($a, $range) = explode("=",$_SERVER['HTTP_RANGE'],2);
      list($range) = explode(",",$range,2);
      list($range, $range_end) = explode("-", $range);
      $range=intval($range);
      if(!$range_end) {
         $range_end=$size-1;
      } else {
         $range_end=intval($range_end);
      }
   
      $new_length = $range_end-$range+1;
      header("HTTP/1.1 206 Partial Content");
      header("Content-Length: $new_length");
      header("Content-Range: bytes $range-$range_end/$size");
    } else {
      $new_length=$size;
      header("Content-Length: ".$size);
    }
   
    /* output the file itself */
    $chunksize = 1*(1024)*(1024); //you may want to change this
    $bytes_send = 0;
    if ($file = fopen($file, 'r'))
    {
      if(isset($_SERVER['HTTP_RANGE']))
      fseek($file, $range);
   
      while(!feof($file) &&
         (!connection_aborted()) &&
         ($bytes_send<$new_length)
           )
      {
         $buffer = fread($file, $chunksize);
         print($buffer); //echo($buffer); // is also possible
         flush();
         $bytes_send += strlen($buffer);
      }
    fclose($file);
    } else die('Error - can not open file.');
   
   die();
   }
   // END OUTPUT_FILE function

Hi, I have decent knowledge of htaccess and know enough about php/mysql so a little direction/advice is mostly what I need. I host a website(site1.com) that has links to files that are hosted on a different website(site2.com) on a different server. When a file link is clicked from site1.com, first it will go to a local php file(within site1.com) that checks that the user is logged in and make sure the file exists. Then it redirects(using a simple header function) to the file located at site2.com to begin download.

But since my files at site2.com stored in a simple folder(if you knew the folder name, you could download all the files without having to be logged in), I want a way for site2.com to check that the file request is coming from site1.com(maybe using php referrer?) before it allows the download to proceed. Any ideas?

Hi
I am creating an e-commerce website, where users who pay with their credit card are able to download pdf books.
how can I make a PDF file only accessible for those users (who pay and validate their credit card) and not for everyone ?

I want to know the main idea about securing these files.

Hi,

I'm wondering if anyone knows of any good information regarding downloading files.
I'm looking into creating a relatively simple download system, where people will be sent a link say (download.php?id=dnjwaAYFDAg734) (where id would be an encrypted value, and obviously a lot longer!). That script would then decode the id number and allow the user to download the appropriate file.

Any help would be hugely grateful as I'm a little unsure of where to go and a quick look through google doesn't show too much up.

Thanks

Edd

I have this code and its downloading file nicely. But I want to show a progress bar while downloading file from external server. My existing code shows progress bar but its not effective (ex. if i try to download two media file, one video and another audio, and video size is larger than audio size the audio finishes first and the progress bar shows 100% also suddenly it drops to 50% as the video is still downloading ). I mean it actually shows two progress and I need one. If I could get average percentage value of two progress that would be better. Any suggestion regarding this will be greatly appreciated.
 

<?php
set_time_limit ( 0 );
function define_progress_callback($i) {
global $conn;

curl_setopt($conn[$i], CURLOPT_PROGRESSFUNCTION, function ($resource,$download_size, $downloaded, $upload_size, $uploaded)
{
    if($download_size > 0)
        $progress = round($downloaded / $download_size  * 100);
        echo '<script language="javascript">$(".loader").loader("setProgress", '.$progress.');</script>';
        echo str_pad("",1024," ");
        flush();
        usleep(20000);

});
}

$urls = array("http://example.com/file.mp3",
                "http:/example.com/file.mp4");
$save_to='./tmp/';
$conn = array();
$fp = array();
$mh = curl_multi_init();

    foreach ($urls as $i => $url) {
    $g = $save_to . basename($url);
    $conn[$i]=curl_init($url);
    $fp[$i]=fopen ($g, "wb");
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);    // No certificate
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
        curl_setopt ($conn[$i], CURLOPT_FILE, $fp[$i]);
    curl_setopt ($conn[$i], CURLOPT_HEADER ,0);
    curl_setopt($conn[$i],CURLOPT_CONNECTTIMEOUT,60);
    curl_setopt ($conn[$i], CURLOPT_MAXCONNECTS, 10);
    curl_setopt($conn[$i], CURLOPT_NOPROGRESS, false);
    define_progress_callback($i);
    curl_multi_add_handle ($mh,$conn[$i]);
    }

    do {
    $n=curl_multi_exec($mh,$active);
    }
    while ($active);
    foreach ($urls as $i => $url) {
    curl_multi_remove_handle($mh,$conn[$i]);
    curl_close($conn[$i]);
    fclose($fp[$i]);
    }
curl_multi_close($mh);

?>

Edited by requinix, 18 January 2015 - 08:16 AM.
no code tags meant auto-embedding of mp3