File_exists result cached over a session?

File_exists results (and the results from other file-related functions) are cached (according to the php doc) during the run of a script. For instance, if file_exists returns True for a file once, it won't actually test the file again if file_exists is run again against the file. What I need to know is whether this caching works over a session (not just during a single script run). Thanks. -- Steve Magruder www.webcommons.org