51.4 Who's On?
The who command lists the users logged on to the system now. Here's an example of the output on my system:
Each line shows a different terminal or window. The columns show the username logged on, the tty (3.8 ) number, the login time, and, if the user is coming in via a network (1.33 ) , you'll see (in parentheses) their location. The user hal is logged on twice, for instance.
It's handy to search the output of who with grep (27.1 ) - especially on systems with a lot of users. For example: