[Mediawiki-l] accessing session info from another .php script

[dKosopedia admin]

Let's say I have a v1.11 wiki at www.mydomain.com/wiki/Main_Page,  
with source and all in /w as seems to be standard. I want to provide  
users logged in to the wiki with a set of data management forms, say  
at www.mydomain.com/maint/index.php (and other .php files under / 
maint). I'd like to use the wiki login for /maint authentication, and  
grab the username and userid to put in the database for auditing  
purposes, as well as controlling access to the forms. In other words,  
once users successfully log into the wiki, their session info is used  
to control access by other .php scripts under the same domain.

I have very little php session experience, and so am not sure where  
to start. Do my /maint .php files do a session_start(), and if so,  
what cookies to I look for to get username and userid? Can I just  
check for the username and userid cookies directly (and if so, what  
are they called), or is that open to spoofing? I've looked at my own  
Firefox cookies and see no PHPSESSID, so there must be some other  
session id thingy somewhere.

I must be overlooking the obvious. Any help appreciated.