The rusers command (for remote users) shows you which users are logged in to other machines on your network. Type the rusers command by itself to display each machine on the network and the user(s) logged in to these machines.
$ rusers starbug user2 user1 root earth user1 venus user3
Notice that three users are logged in to the machine starbug.
To display information on a specific remote machine, type the rusers command followed by the name of the machine.
$ rusers starbug starbug user2 user1 root $
The -l option to the rusers command displays the following information.
Machine and terminal names
Time each user logged in
How long each user has been idle (if more than one minute)
Name of the machine that each user logged in from
$ rusers -l starbug root starbug:console Oct 31 11:19 (:0) user2 starbug:pts/7 Oct 31 11:20 40:05 (starbug) user1 starbug:pts/13 Nov 1 14:42 17:18 (starbug) $
You can also use the -l option without providing a machine name.
For more information on the rusers(1) command and its options, refer to the man Pages(1): User Commands.