Force Downloading a PDF file, corrupt file

Question

I've got a problem that has risen many times on SO, but I can't seem to find the solution to mine! I'm trying to deliver a pdf file to the client without it opening in the browser, the file downloads but it is corrupt when I open it and is missing quite a few bytes from the original file. I've tried several such methods for downloading the file but I'll just show you the latest I've used and hopefully get some feedback.

I have also opened the downloaded PDF in a text editor and there are no php errors at the top of it that I can see!

I'm also aware that readfile() is much quicker but for testing purposes I am desperate to get anything working so I used the while(!feof()) approach!

Anyway enough rambling, heres the code (taken from why my downloaded file is alwayes damaged or corrupted?):

$file     = __DIR__ . '/reports/somepdf.pdf';
$basename = basename($file);
$length   = sprintf("%u", filesize($file));

header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="' . $basename . '"');
header('Content-Transfer-Encoding: binary');
header('Connection: Keep-Alive');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
header('Content-Length: ' . $length);

ob_clean();
set_time_limit(0);
readfile($file);

Also to note was the difference in file size:

Original: 351,873 bytes
Downloaded: 329,163 bytes

Answer 1

Make sure you're not running any compression output buffering handlers, such as ob_gzhandler. I had a similar case and I had to disable output buffering for this to work properly