who − show who is logged on


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


−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

−i, −−idle

add idle time as HOURS:MINUTES, . or old (deprecated, use −u)

−l, −−login

print system login processes


attempt to canonicalize hostnames via DNS


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


same as −T


same as −T


display this help and exit


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 bugs to <bug-coreutils@gnu.org>.


Copyright © 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


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

should give you access to the complete manual.