We can check who is currently logged on to the system using the w command. This gives us some basic system statistics and list all users logged on:
$w 8:54pm up 22 min, 3 users, load average: 0.00, 0.02, 0.04 User tty login@ idle JCPU PCPU what jasonw tty5 8:42pm 10 -bash asti tty6 8:43pm 11 (bash) markst ttyp2 8:32pm w $
We can also see when the user logged on, how long he has been idle and what he is currently doing. Two of the users seem to be doing nothing as only their shell appears as their active process. The third user is actually running the w program.