who -u should be current.
From man as well:
"-u Lists only those users who are currently logged
in. name is the user's login name. line is the
name of the line as found in the directory /dev.
The time field indicates when the user logged in."
Why you need to remove? What old entries you are getting? Are they not logged in? Kill their session if you want to close them.
Dreams are not which you see while sleeping, Dreams are which doesnt allow you to sleep while you are chasing for them!!
