who

Show who is logged on

Overview

Displays a list of users who are currently logged into the computer.

who [OPTION]... [ FILE | ARG1 ARG2 ]

$ who

Show who is currently logged on.

$ who -b

Show system boot time.

Output the last part of files

Execute a command as another user (superuser)

Create a new user or update default new user information

Modify a user account

Delete a user account and related files

Update user`s authentication tokens (passwords)

whousersloggedonsessionssystem