who,w, finger, last - Who are the users?

who command:

It displays us how many number of users are logged in into the server.

who –H

Shows with header.

who –Hu

Shows with header in more details including idle time.

who am i

The total details of current user -you.

whoami

Only the username – your username.

who –b

Time of the last system boot.

who –i

Idle time as Hours:Minutes.

who –r

Print current run level.

who –u

List users logged in including idle time.

w command:

Shows who are logged in and what they are doing.

finger command

it will show two more extra information like office address and phone number.

finger –l

it gives all the information about which shell you are logged in.

last command

it will display how many users are previously logged in and logged off.