---
name: "who"
section: "1"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd", "openbsd", "macos"]
url: "https://new.carta.tech/who"
---

# who(1)

display who is on the system

## NAME

**who** – display who is on the system

## SYNOPSIS

**who** \[**-abHmqsTu**\] \[**am** **I**\] \[*file*\]

## DESCRIPTION

The **who** utility displays information about currently logged in users. By default, this includes the login name, tty name, date and time of login and remote hostname if not local.

The options are as follows:

- **-a**

  Equivalent to **-bTu**, with the exception that output is not restricted to the time and date of the last system reboot.

- **-b**

  Write the time and date of the last system reboot.

- **-H**

  Write column headings above the output.

- **-m**

  Show information about the terminal attached to standard input only.

- **-q**

  “Quick mode”: List the names and number of logged in users in columns. All other command line options are ignored.

- **-s**

  Show the name, line and time fields only. This is the default.

- **-T**

  Indicate whether each user is accepting messages. One of the following characters is written:

  - \+

    User is accepting messages.

  - \-

    User is not accepting messages.

  - ?

    An error occurred.

- **-u**

  Show idle time for each user in hours and minutes as *hh*:*mm*, ‘.’ if the user has been idle less than a minute, and “old” if the user has been idle more than 24 hours.

- **am** **I**

  Equivalent to **-m**.

By default, **who** gathers information from the file */var/run/utx.active*. An alternate *file* may be specified which is usually */var/log/utx.log* (or */var/log/utx.log.\[0-6\]* depending on site policy as *utx.log* can grow quite large and daily versions may or may not be kept around after compression by [ac(8)](/ac/8.md)). The *utx.log* file contains a record of every login, logout, crash, shutdown and date change since *utx.log* was last truncated or created.

If */var/log/utx.log* is being used as the file, the user name may be empty or one of the special characters '\|', '}' and '~'. Logouts produce an output line without any user name. For more information on the special characters, see [getutxent(3)](/getutxent/3.md).

## ENVIRONMENT

The COLUMNS, LANG, LC\_ALL and LC\_TIME environment variables affect the execution of **who** as described in [environ(7)](/environ/7.md).

## FILES

- */var/run/utx.active*

  - */var/log/utx.log*

  - */var/log/utx.log.\[0-6\]*

  ## EXIT STATUS

The **who** utility exits 0 on success, and \>0 if an error occurs.

## EXAMPLES

Show a brief summary of who is logged in:

```
$ who -q
fernape          root             root
# users = 3
```

Show who is logged in along with the line and time fields (without the headers):

```
$ who -s
fernape          ttyv0        Aug 26 16:23
root             ttyv1        Aug 26 16:23
root             ttyv2        Aug 26 16:23
```

Show information about the terminal attached to standard input:

```
$ who am i
fernape                       Aug 26 16:24
```

Show time and date of the last system reboot, whether the users accept messages and the idle time for each of them:

```
$ who -a
                 - system boot  Aug 26 16:23   .
fernape          - ttyv0        Aug 26 16:23   .
root             - ttyv1        Aug 26 16:23   .
root             - ttyv2        Aug 26 16:23   .
```

Same as above but showing headers:

```
$ who -aH
NAME             S LINE         TIME         IDLE  FROM
                 - system boot  Aug 26 16:23   .
fernape          - ttyv0        Aug 26 16:23   .
root             - ttyv1        Aug 26 16:23 00:01
root             - ttyv2        Aug 26 16:23 00:01
```

## SEE ALSO

[last(1)](/last/1.md), [users(1)](/users/1.md), [w(1)](/w/1.md), [getutxent(3)](/getutxent/3.md)

## STANDARDS

The **who** utility conforms to IEEE Std 1003.1-2001 (“POSIX.1”).

## HISTORY

A **who** command appeared in Version 1 AT&T UNIX.