If you want to see which users are connected to your linux box, the “who” command can let you do the magic. The output will be like below:
[root@localhost ~]# who
root :0 2007-03-12 04:17
dan pts/1 2007-03-16 07:07 (192.168.0.1)
So here two users named root and dan are connected to my linux box.