Twitter JS API - get current logged in user

I am using twitter @anywhere JS API in my application and don't know ho开发者_JAVA百科w to use their methods and properly execute them. At present, I am following this docs for the API.

I am working on a scenario where, I need to check from my app, if any twitter user is logged in on the same browser, get the current twitter user details and cross check with my app for the twitter user. If the user exists in my app, automatically login the user. (more importantly it should not ask the user to connect to the twitter app. Without asking the credentials I need to get the currentUser)

NOTE: Facebook already supports this type of method. We can get the facebook loggedin user session from getSession() method.

Is there anyone there to help me out on this one?