theshell.ch/site/pages/cmd/interm/who.html

---
layout: page
category-page: intermediate
category-title: Intermediate commands
author: Marco Farace
title: who
---
The <code>who</code> command displays a list of all logged in users/display info
about current user

The who utility displays a list of all users currently logged on, showing
for each user the login name, tty name, the date and time of login, and
hostname if not local.<br>

<h3>Flags</h3>
Here are just some of the most useful options for this command:

<ul>
    <li>-b: Display time of last system boot.</li>
    <li> -d: Print dead processes.</li>
    <li>-H: Write column headings above the regular output.</li>
    <li>-m: Only print information about the current terminal.</li>
    <li>-q: <i>Quick mode</i>: List only the names and the number of users currently logged on.
        When this option is used, all other options are
        ignored.
    </li>
    <li>-s: List only the name, line and time fields. This is the default.</li>
    <li>-T: Print a character after the user name indicating the state of the
        terminal line: "+" if the terminal is writable; "-" if it is not;
        and "?" if a bad line is encountered.
    </li>
    <li>-u: Print the idle time for each user, and the associated process ID.</li>
    <li>am I: Returns the invoker's real user name. You can also use <code>whoami</code></li>
    <li>file: By default, who gathers information from the file /var/run/utmpx.
        An alternative file may be specified.
    </li>
</ul>