checking for a logged user

[Pablo Gra\~na]

Hi there. I need to do something very specific with CAS. I want to know 
in certain service if I am already logged in to CAS. Let me expand a 
little bit:

Suppose I have two services. One of them (service1) forces me to log in 
to CAS. The other one (service2) has two modes: an anonymous mode and a 
logged in mode. The problem is that I need to know in service2 if I am 
logged in service1 (or in CAS).

One option would be, when a user has no session in service2, redirect to 
CAS with some request parameter. This parameter indicates CAS that it 
should not present the user a login page, just redirect with the token 
if the user has already logged in, or with some other parameter to 
notify that the user has not logged in.

Is this possible? Any hints?

Thanks a lot.

-- 
Pablo Gra\~na
Chief Architect
Globant
Arg Office: +54 (11) 4109 1743
UK  Office: +44 (20) 7043 8269 int 8043
US  Office: +1 (212) 400 7686 int 8043