Question

I have an executable hosted at code.google.com (say, http://code.google.com/fold/file1.exe). When the user browses to http://mysite.com/download.exe, I want them to automatically get the content of the file http://code.google.com/fold/file1.exe without any redirect. The user should think that he/she is downloading the file from http://mysite.com/download.exe not http://code.google.com/fold/file1.exe.

How might I do this, using PHP? Is there any special term for this process?

Answer 1

You can use URL rewriting to pass in the file name as an argument to a script. Your script (downloadexecutable.php in this example) would respond to a $_GET argument ‘q’ which would contain ‘download’:

<?php
if (isset($_GET['q']) && $_GET['q'] == "download") {
    //you will want to:
    //1) set Content-type to be the correct type...I just set it to octet-stream because I'm not sure what it should be
    header('Pragma: public');   // required
    header('Expires: 0');       // no cache
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Cache-Control: private',false);
    header('Content-Type: application/octet-stream');
    header('Content-Disposition: attachment; filename="'.basename('http://code.google.com/fold/file1.exe').'"');
    header('Content-Transfer-Encoding: binary');
    header('Content-Length: '.filesize('http://code.google.com/fold/file1.exe'));    // provide file size
    echo file_get_contents('http://code.google.com/fold/file1.exe');      // push it out
    exit()
}
?>

Then, you would enable URL rewriting on Apache in an .htaccess file in your root directory like so:

RewriteEngine On
RewriteRule ^(.+)\.exe$ /downloadexecutable.php?q=$1 [NC,L]

When the user requests any file ending in .exe, downloadexecutable.php should be executed as follows:

Request: http://yoursite.com/download.exe

What actually gets processed by PHP: http://yoursite.com/downloadexecutable.php?q=download

Request: http://yoursite.com/this/could/be/a/bug.exe

Processed: http://yoursite.com/downloadexecutable.php?q=this/could/be/a/bug

Obviously it would need a bit of work and I haven’t tested any of the above, but if you fool around with it a bit and are willing to use google, you should be able to get it working.

URL Rewriting tutorial: http://www.addedbytes.com/articles/for-beginners/url-rewriting-for-beginners/

Source for the php stuff: http://snipplr.com/view/22546/