File Auto-Download Problem

Rothy

I found this script somewhere on the net, basically it forces a file to be downloaded instead of viewed inside of the web browser, by making it an attachment in the header. The code is:

if( $filename == "" ) 
{
  echo "ERROR: download file NOT SPECIFIED. Please Contact the Staff to Notify them of this Error.";
  exit;
} elseif ( ! file_exists( $filename ) ) 
{
  echo "ERROR: File not found. Please Contact the Staff to Notify them of this Error.";
  exit;
};

header("HTTP/1.1 200 OK");   

header("Content-Length: ".filesize($filename));   

header("Content-Type: application/force-download");   

header("Content-Disposition: attachment; filename=\"".basename($filename)."\";");   

header("Content-Transfer-Encoding: binary"); 
readfile($filename);
}
?>

The problem is, while this works and does cause them to download the file, the download stops half way for many people, so incomplete files are downloaded. This only happens for some people, I dont actually have this problem, when I try everything downloads correctly.

Anyone have an idea what might be causing this problem?

etully

It's probably a browser issue. HTTP isn't a great way to download very large files. (How large are these files and what browser are the people using when it fails?)

If it's not a browser issue, then it could be a network issue. Are those people behind a firewall? Are they using a different ISP than you?

Just for troubleshooting, what happens if those people try to download the file by right clicking on a link like this: <a href="<? print "$filename"; ?>">Right Click Here to Download</a>

Rothy

Right click and Save Target as works fine, its just this script. Its a very common problem, ive receieved at least 100 complaints about it. The file sizes range from 2 MB to 80MB, the same problem happens for all of them.

Rothy

Bumping

etully

I don't think that this is a PHP issue. It's most likely a browser issue. What browser are people using when it fails? If one browser works every time and another browser fails every time, then what you're going to have to do to solve this is find out why the browser doesn't like it.

It seems to me that the difference between "Right-Click-Save-Target" and Auto-Download is that one goes to the hard drive and the other goes to the browser for rendering and that might be where it's failing. Maybe it's failing because the file is too large or maybe it's because the MIME type isn't set right for the file type?

When it fails for people, does it fail consistently for them or just occasionally when they use the same browser downloading the same file?

Rothy

It fails consistantly for the people that it doesnt work for, and they use both IE and Firefox. However I use both IE and Firefox and it works fine for me, and the other half of people.

etully

I don't know what the problem is but we know it's not a PHP problem (because it works for you) and we know it's not a browser problem (because it works for you) so it must be a network problem. I suspect that PHP is timing out because the user isn't receiving the file fast enough. You are turning PHP into a mini web server and it's not designed to do that. If it's not a PHP timeout issue, then it could be that the other users are behind a firewall that or they are using Network Address Translation (NAT) and one of these is screwing up the transmission but I think it's more likely that PHP is timing out.

Rothy

Anyway to prevent PHP from timing out?

jsim

Try ini_set("max_execution_time",0);