You are here: >

Linux and Unix who command

who commandAbout who
who syntax
who examples
Related commands
Linux and Unix main page

About who

Displays who is logged on to the system.


The who command prints information about all users who are currently logged in.

who Syntax

who [ OPTION ]... [ FILE ] [ am i ]


-a, --all Same as using the options -b -d --login -p -r -t -T -u.
-b, --boot Display the time of the last system boot.
-d, --dead Display dead processes.
-H, --heading Print a line of column headings.
--ips Print IP addresses instead of hostnames. with --lookup, canonicalizes based on stored IP, if available, rather than stored hostname.
-l, --login Print system login processes.
--lookup Attempt to canonicalize hostnames via DNS.
-m Only print information about the user and host associated with standard input (the terminal where the command was issued). This method adheres to the POSIX standard.
-p, --process Print active processes spawned by init.
-q, --count Displays all login names, and a count of all logged-on users.
-r, --runlevel Print the current runlevel.
-s, --short Print only name, line, and time fields. This is the default.
-t, --time Print the last time the system clock was changed, if the information is available.
-T, -w, --mesg Add a character which indicates the state of the terminal line: "+" if the terminal is writable, "-" if it is not, or "?" if a bad line is encountered.
-u, --users Print the idle time for each user, and the process ID.
--message Same as -T.
--writable Same as -T.
--help Display a help message, and exit.
--version Display version information, and exit.


If FILE is specified, who gathers its information from this file. Otherwise, it reads from a default file location (usually /var/run/utmp).

If the arguments "am i" are specified, who assumes the -m option.

who examples


Displays the username, line, and time of all currently logged-in sessions. For example:


who am i

Displays the same information, but only for the terminal session where the command was issued, for example:

alan     pts/3        2013-12-25 08:52 (:0.0)

who -aH

Displays "all" information, and headers above each column of data, for example:

NAME       LINE         TIME             IDLE          PID COMMENT  EXIT
                        2014-01-17 07:00               154 id=si    term=0 exit=0
           system boot  2014-01-17 07:00
           run-level 2  2014-01-17 07:00                   last=S
                        2014-01-17 07:01              1607 id=l2    term=0 exit=0
LOGIN      tty6         2014-01-17 07:01              2809 id=6
LOGIN      tty5         2014-01-17 07:01              2808 id=5
LOGIN      tty4         2014-01-17 07:01              2807 id=4
LOGIN      tty2         2014-01-17 07:01              2805 id=2
LOGIN      tty1         2014-01-17 07:01              2804 id=1
LOGIN      tty3         2014-01-17 07:01              2806 id=3
           pts/0        2014-01-17 11:31              2811 id=ts/0  term=0 exit=0
lucy     + pts/1        2014-01-17 22:42   .          6609 (:0.0)
           pts/2        2014-01-18 02:14                 0 id=/2    term=0 exit=0
           pts/3        2014-01-18 02:08                 0 id=/3    term=0 exit=0
           pts/4        2014-01-17 21:30                 0 id=/4    term=0 exit=0
lucy     + pts/0        2014-01-17 22:01 01:04        6330 (:0.0)

date — Output the current date and time.
last — Display a listing of the most recently logged-in users.
login — Begin a session on a system.
mesg — Control if (non-root) users can send messages to your terminal.
su — Become the superuser or another user.
w — Show who is logged on and what they are doing.
whoami — Print your effective userid.