download file generator?

[conical]

Hey, I've been searching around on the forums for a few days now and couldn't find what I was looking for --

I'm making this download system that generates a PDF from a directory; and then the users will be able to download the file. But I want PHP to create a temporary file (like, named session_id().pdf or something) that will automatically delete itself after the session expires.

Any way to do this?

thanks