w
The w command displays a list of all logged in to the server and what they are doing. This command is similar to who command, but ends up displaying more information about logged in users.
$ w
Sample outputs:
vivek pts/0 192.168.1.6 14:10 3:24m 2.15s 0.00s dbus-launch --auto
root pts/1 192.168.1.6 14:51 1:41m 0.16s 0.00s pager -s
nixcraft pts/2 192.168.1.6 14:52 13:07 0.41s 0.02s vi /etc/passwd
root pts/3 192.168.1.6 17:21 3.00s 0.12s 0.01s w -h