i would like to redirect/forward the user who are referred by a link. The problem is when it comes to do the same thing with files. I would like to allow ppl to download who referred by that link only.
Just write the logic into your script. You may need a database to store all the referrer - file matches in it as it would be cumbersome to manage in the script. Ofcourse, you'd then need to write an admin section... so you need to scope out your requirements first.