Linux Command - who

who - display who is logged in and related data(processes, boot time).

Options

Option Description
-a same as -b -d –login -p -r -t -T -u
-b time of last system boot
-d dead processes
-l, –login print system login processes
-p print active processes spawned by init
-r print current runlevel
-t print last system clock change
-T add user’s message status as +, - or ?
-u list users loggin in
-H print line of column headings

Example

Display current user info with Heading

1
who -H

Display all logged in users’ info

1
who -a

Reference