Q. How do I display who is on the UNIX / Linux system?
A. On a Linux (on Solaris/FreeBSD or any other UNIX) system, many users will be sharing the same server.
Users will use telnet (outdated and insecure) or ssh (secure and highly recommended) to login remotely.
So if you want to find out your friend or a coworker is logged in or not, use the following commands.
If you want to find out who's logged in on the Linux server including what time they logged in and from which network computer then you can use who command:
who command ~ show who is logged on
who commands works with almost all Linux and UNIX like oses. It show who is logged on to your system. It displays information about currently logged in users. By default, this includes the login name, tty name, date and time of login and remote hostname if not local.
raj ttypV Jan 17 07:23 . (192.168.1.10) ben ttypW Jan 17 07:42 . (192.168.1.11) miku ttypX Jan 17 07:28 . (user-del-net-202.vsnl.net.in) root ttypY Jan 17 04:11 . (126.96.36.199) roomy ttyq0 Jan 17 07:32 . (org-rev-1.bsnl.net.in) anita ttyq2 Jan 17 07:33 . (192.168.5.112) gads ttyq3 Jan 17 07:40 . (gtw-1.nixcraft.in) bencs ttyq5 Jan 17 07:44 . (dsl5.bsnl.co.in) pol20um ttyq6 Jan 17 07:47 . (gtw-2.nixcraft.co.in)
Sometime you just want to find out if user raj logged in or not then you can use grep command:
$ who | grep raj
Try out following command if you have more than 20+ users logged in (so that you can see one page of logged in users at a time):
$ who | less $ who | more