how can get userid of this user?

hi.
I want to get the profile of the user that is currently being viewed. for example i am user A and want to see user B profile. how i can get the userid of user B?
i use some extension (Fabrik) that need user id currently viewed then do some process. is there any way to get userid in code? i can't use CB substitution like [userid] because i use php eval code . i must get userid from somthing such as query string or Request header. what is your suggest?

i find that... for future users:
global $_CB_framework;
$userid=$_CB_framework->displayedUser();
return $userid;
please say me is it heavy for proccess in joomla or is it non-standard to use global $_CB_framework?

i have other problem. when i use CB user list, this method not work, what can i do if i want show user id in list column with the php code

displayedUser is only set when viewing a profile. It is not set when viewing a userlist because it makes no sense to set it there since it's a list of users. Yes, it's fine to use the $_CB_framework global.

what can i do if i want show user id in list column with the php code?
is there any php function?

Create a Custom HTML field with [user_id] set as the HTML. You can then display it in a column of your userlist.