# man > WHO(1)

> **TLDR:** Display who is logged in and related data (processes, boot time).
>
- Display the username, line, and time of all currently logged-in sessions:
  `who`
- Display all available information:
  `who {{-a|--all}}`
- Display all available information with table headers:
  `who {{-aH|--all --heading}}`

*Source: tldr-pages*

---

[_WHO_(1)](https://www.chedong.com/phpMan.php/man/WHO/1/markdown)                                      User Commands                                     [_WHO_(1)](https://www.chedong.com/phpMan.php/man/WHO/1/markdown)

## 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     

### -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.

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

## REPORTING BUGS
       GNU coreutils online help: <<https://www.gnu.org/software/coreutils/>>
       Report any translation bugs to <<https://translationproject.org/team/>>

## COPYRIGHT
       Copyright © 2023 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'

GNU coreutils 9.4                           January 2026                                      [_WHO_(1)](https://www.chedong.com/phpMan.php/man/WHO/1/markdown)