WHO(1)

NAME
who - show who is logged on

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

DESCRIPTION

Print information about users who are currently logged in.

-a, --all
    same as -b -d --login -p -r -t -T -u

-b, --boot
    time of last system boot

-d, --dead
    print dead processes

-H, --heading
    print line of column headings

-l, --login
    print system login processes

--lookup
    attempt to canonicalize hostnames via DNS

-m  only hostname and user associated with standard input

-p, --process
    print active processes spawned by init

-q, --count
    all login names and number of users logged on

-r, --runlevel
    print current runlevel

-s, --short
    print only name, line, and time (default)

-t, --time
    print last system clock change

-T, -w, --mesg
    add user's message status as +, - or ?

-u, --users
    list users logged in, including idle time

--message
    same as -T

--writable
    same as -T

--help
    display this help and exit

--version
    output version information and exit

If FILE is not specified, use /var/run/utmp. /var/log/wtmp as FILE is common. If ARG1 ARG2 given, -m presumed: 'am i' or 'mom likes' are usual.

AUTHOR
Written by Joseph Arceneaux, David MacKenzie, and Michael Stone.

REPORTING BUGS
Report bugs to: bug-coreutils@gnu.org
GNU coreutils home page: <https://www.gnu.org/software/coreutils/>
General help using GNU software: <https://www.gnu.org/gethelp/>
Report any translation bugs to <https://translationproject.org/team/>

COPYRIGHT
Copyright © 2026 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

SEE ALSO
Full documentation <https://www.gnu.org/software/coreutils/who>
or available locally via: info '(coreutils) who invocation'