PHP: Force file download and IE, yet again

Question

Folks, I know there have been lots of threads about forcing the download dialog to pop up, but none of the solutions worked for me yet.

My app sends mail to the use

Answer 1

Your no-cache directives (Vary, Expires, Pragma) are causing the problem.

See http://blogs.msdn.com/ieinternals/archive/2009/10/02/Internet-Explorer-cannot-download-over-HTTPS-when-no-cache.aspx

Answer 2

This will check for versions of IE and set headers accordingly.

// assume you have a full path to file stored in $filename
if (!is_file($filename)) {
  die('The file appears to be invalid.');
}

$filepath = str_replace('\\', '/', realpath($filename));
$filesize = filesize($filepath);
$filename = substr(strrchr('/'.$filepath, '/'), 1);
$extension = strtolower(substr(strrchr($filepath, '.'), 1));

// use this unless you want to find the mime type based on extension
$mime = array('application/octet-stream');

header('Content-Type: '.$mime);
header('Content-Disposition: attachment; filename="'.$filename.'"');
header('Content-Transfer-Encoding: binary');
header('Content-Length: '.sprintf('%d', $filesize));
header('Expires: 0');

// check for IE only headers
if (preg_match('~MSIE|Internet Explorer~i', $_SERVER['HTTP_USER_AGENT']) || (strpos($_SERVER['HTTP_USER_AGENT'], 'Trident/7.0; rv:11.0') !== false)) {
  header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
  header('Pragma: public');
} else {
  header('Pragma: no-cache');
}

$handle = fopen($filepath, 'rb');
fpassthru($handle);
fclose($handle);

Answer 3

If you're trying to get the file to download every time, change the content type to 'application/octet-stream'.

Try it without the pragma statement.

Answer 4

Just use:

header('Content-Disposition: attachment');

That's all. (Facebook does the same.)