WHO

who − show who is logged on

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

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 stdin

−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

−−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.

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

Report who bugs to bug−coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
Report who translation bugs to <http://translationproject.org/team/>

Copyright © 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://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.

The full documentation for who is maintained as a Texinfo manual. If the info and who programs are properly installed at your site, the command

info coreutils 'who invocation'

should give you access to the complete manual.