roundcubemail/program/lib/Roundcube/rcube.php
public function get_user_id()
    {
        if (is_object($this->user)) {
            return $this->user->ID;
        }
        else if (isset($_SESSION['user_id'])) {
            return $_SESSION['user_id'];
        }

        return null;
    }
public function get_user_id()
    {
        if (is_object($this->user)) {
            return $this->user->ID;
        }
        else if (isset($_SESSION['user_id'])) {
            return $_SESSION['user_id'];
        }

        return null;
    }
public function get_user_id ( ) { if ( is_object ( $ this -> user ) ) { return $ this -> user -> ID ; } else if ( isset ( $ _SESSION [ 'user_id' ] ) ) { return $ _SESSION [ 'user_id' ] ; } return null ; }
Getter for logged user ID.

@return mixed User identifier
Getter for logged user ID .