Forum First possible hook, where userid is known???

[محروم.كوم]

Hello what is the first possible hook, where I can check userid?

I need to know ASAP does someone is logged in or not, i.e. by:
PHP Code:
$vbulletin->userinfo['userid']

If there is other way to check it - please tel how. I do not care how I will check it - I care do do it ASAP, to avoid unnecessary evaluation (I'm redirecting under some conditions for guests).

Right now I'm checking it in global_start but:
1. Lot of things are made earlier - I could stop it if I know earlier does user is logged. So now it is just waist of resources.
2. And most important - not all vB places supports global_start hook. As I remember CMS is not using this hook.

PS.
Also please answer for same question, but for vB 3.8 __DEFINE_LIKE_SHARE__