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


print ips instead of hostnames. with --lookup, canonicalizes based on stored IP, if available, rather than stored hostname

-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.


GNU coreutils online help: <>
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Copyright © 2020 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.


Full documentation <>
or available locally via: info '(coreutils) who invocation'