[thirdparty/systemd.git] / man / systemctl.xml

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  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
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<refentry id="systemctl"
          xmlns:xi="http://www.w3.org/2001/XInclude">

  <refentryinfo>
    <title>systemctl</title>
    <productname>systemd</productname>

    <authorgroup>
      <author>
        <contrib>Developer</contrib>
        <firstname>Lennart</firstname>
        <surname>Poettering</surname>
        <email>lennart@poettering.net</email>
      </author>
    </authorgroup>
  </refentryinfo>

  <refmeta>
    <refentrytitle>systemctl</refentrytitle>
    <manvolnum>1</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>systemctl</refname>
    <refpurpose>Control the systemd system and service manager</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>systemctl</command>
      <arg choice="opt" rep="repeat">OPTIONS</arg>
      <arg choice="plain">COMMAND</arg>
      <arg choice="opt" rep="repeat">NAME</arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><command>systemctl</command> may be used to introspect and
    control the state of the <literal>systemd</literal> system and
    service manager. Please refer to
    <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
    for an introduction into the basic concepts and functionality this
    tool manages.</para>
  </refsect1>

  <refsect1>
    <title>Options</title>

    <para>The following options are understood:</para>

    <variablelist>
      <varlistentry>
        <term><option>-t</option></term>
        <term><option>--type=</option></term>

        <listitem>
          <para>The argument should be a comma-separated list of unit
          types such as <option>service</option> and
          <option>socket</option>.
          </para>

          <para>If one of the arguments is a unit type, when listing
          units, limit display to certain unit types. Otherwise, units
          of all types will be shown.</para>

          <para>As a special case, if one of the arguments is
          <option>help</option>, a list of allowed values will be
          printed and the program will exit.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--state=</option></term>

        <listitem>
        <para>The argument should be a comma-separated list of unit
        LOAD, SUB, or ACTIVE states. When listing units, show only
        those in specified states. Use <option>--state=failed</option>
        to show only failed units.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-p</option></term>
        <term><option>--property=</option></term>

        <listitem>
          <para>When showing unit/job/manager properties with the
          <command>show</command> command, limit display to properties
          specified in the argument. The argument should be a
          comma-separated list of property names, such as
          <literal>MainPID</literal>. Unless specified, all known
          properties are shown. If specified more than once, all
          properties with the specified names are shown. Shell
          completion is implemented for property names.</para>

          <para>For the manager itself,
          <command>systemctl show</command> will show all available
          properties. Those properties are documented in
          <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
          </para>

          <para>Properties for units vary by unit type, so showing any
          unit (even a non-existent one) is a way to list properties
          pertaining to this type. Similarly showing any job will list
          properties pertaining to all jobs. Properties for units are
          documented in
          <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
          and the pages for individual unit types
          <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
          <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
          etc.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-a</option></term>
        <term><option>--all</option></term>

        <listitem>
          <para>When listing units, show all loaded units, regardless
          of their state, including inactive units. When showing
          unit/job/manager properties, show all properties regardless
          whether they are set or not.</para>
          <para>To list all units installed on the system, use the
          <command>list-unit-files</command> command instead.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-r</option></term>
        <term><option>--recursive</option></term>

        <listitem>
          <para>When listing units, also show units of local
          containers. Units of local containers will be prefixed with
          the container name, separated by a single colon character
          (<literal>:</literal>).</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--reverse</option></term>

        <listitem>
          <para>Show reverse dependencies between units with
          <command>list-dependencies</command>, i.e. follow
          dependencies of type <varname>WantedBy=</varname>,
          <varname>RequiredBy=</varname>,
          <varname>RequiredByOverridable=</varname>,
          <varname>PartOf=</varname>, <varname>BoundBy=</varname>,
          instead of <varname>Wants=</varname> and similar.
          </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--after</option></term>

        <listitem>
          <para>With <command>list-dependencies</command>, show the
          units that are ordered before the specified unit. In other
          words, recursively list units following the
          <varname>After=</varname> dependency.</para>

          <para>Note that any <varname>After=</varname> dependency is
          automatically mirrored to create a
          <varname>Before=</varname> dependency. Temporal dependencies
          may be specified explicitly, but are also created implicitly
          for units which are <varname>WantedBy=</varname> targets
          (see
          <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>),
          and as a result of other directives (for example
          <varname>RequiresMountsFor=</varname>). Both explicitly
          and implicitly introduced dependencies are shown with
          <command>list-dependencies</command>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--before</option></term>

        <listitem>
          <para>With <command>list-dependencies</command>, show the
          units that are ordered after the specified unit. In other
          words, recursively list units following the
          <varname>Before=</varname> dependency.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-l</option></term>
        <term><option>--full</option></term>

        <listitem>
          <para>Do not ellipsize unit names, process tree entries,
          journal output, or truncate unit descriptions in the output
          of <command>status</command>, <command>list-units</command>,
          <command>list-jobs</command>, and
          <command>list-timers</command>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--show-types</option></term>

        <listitem>
          <para>When showing sockets, show the type of the socket.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--job-mode=</option></term>

        <listitem>
        <para>When queuing a new job, this option controls how to deal with
        already queued jobs. It takes one of <literal>fail</literal>,
        <literal>replace</literal>,
        <literal>replace-irreversibly</literal>,
        <literal>isolate</literal>,
        <literal>ignore-dependencies</literal>,
        <literal>ignore-requirements</literal> or
        <literal>flush</literal>. Defaults to
        <literal>replace</literal>, except when the
        <command>isolate</command> command is used which implies the
        <literal>isolate</literal> job mode.</para>

        <para>If <literal>fail</literal> is specified and a requested
        operation conflicts with a pending job (more specifically:
        causes an already pending start job to be reversed into a stop
        job or vice versa), cause the operation to fail.</para>

        <para>If <literal>replace</literal> (the default) is
        specified, any conflicting pending job will be replaced, as
        necessary.</para>

        <para>If <literal>replace-irreversibly</literal> is specified,
        operate like <literal>replace</literal>, but also mark the new
        jobs as irreversible. This prevents future conflicting
        transactions from replacing these jobs (or even being enqueued
        while the irreversible jobs are still pending). Irreversible
        jobs can still be cancelled using the <command>cancel</command>
        command.</para>

        <para><literal>isolate</literal> is only valid for start
        operations and causes all other units to be stopped when the
        specified unit is started. This mode is always used when the
        <command>isolate</command> command is used.</para>

        <para><literal>flush</literal> will cause all queued jobs to
        be canceled when the new job is enqueued.</para>

        <para>If <literal>ignore-dependencies</literal> is specified,
        then all unit dependencies are ignored for this new job and
        the operation is executed immediately. If passed, no required
        units of the unit passed will be pulled in, and no ordering
        dependencies will be honored. This is mostly a debugging and
        rescue tool for the administrator and should not be used by
        applications.</para>

        <para><literal>ignore-requirements</literal> is similar to
        <literal>ignore-dependencies</literal>, but only causes the
        requirement dependencies to be ignored, the ordering
        dependencies will still be honoured.</para>
        </listitem>

      </varlistentry>

      <varlistentry>
        <term><option>-i</option></term>
        <term><option>--ignore-inhibitors</option></term>

        <listitem>
          <para>When system shutdown or a sleep state is requested,
          ignore inhibitor locks. Applications can establish inhibitor
          locks to avoid that certain important operations (such as CD
          burning or suchlike) are interrupted by system shutdown or a
          sleep state. Any user may take these locks and privileged
          users may override these locks. If any locks are taken,
          shutdown and sleep state requests will normally fail
          (regardless of whether privileged or not) and a list of active locks
          is printed. However, if <option>--ignore-inhibitors</option>
          is specified, the locks are ignored and not printed, and the
          operation attempted anyway, possibly requiring additional
          privileges.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-q</option></term>
        <term><option>--quiet</option></term>

        <listitem>
          <para>Suppress printing of the results of various commands
          and also the hints about truncated log lines. This does not
          suppress output of commands for which the printed output is
          the only result (like <command>show</command>). Errors are
          always printed.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--no-block</option></term>

        <listitem>
          <para>Do not synchronously wait for the requested operation
          to finish. If this is not specified, the job will be
          verified, enqueued and <command>systemctl</command> will
          wait until the unit's start-up is completed. By passing this
          argument, it is only verified and enqueued.</para>
        </listitem>
      </varlistentry>

      <xi:include href="user-system-options.xml" xpointer="user" />
      <xi:include href="user-system-options.xml" xpointer="system" />

      <!-- we do not document -failed here, as it has been made
           redundant by -state=failed, which it predates. To keep
           things simple we only document the new switch, while
           keeping the old one around for compatibility only. -->

      <varlistentry>
        <term><option>--no-wall</option></term>

        <listitem>
          <para>Do not send wall message before halt, power-off,
          reboot.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--global</option></term>

        <listitem>
          <para>When used with <command>enable</command> and
          <command>disable</command>, operate on the global user
          configuration directory, thus enabling or disabling a unit
          file globally for all future logins of all users.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--no-reload</option></term>

        <listitem>
          <para>When used with <command>enable</command> and
          <command>disable</command>, do not implicitly reload daemon
          configuration after executing the changes.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--no-ask-password</option></term>

        <listitem>
          <para>When used with <command>start</command> and related
          commands, disables asking for passwords. Background services
          may require input of a password or passphrase string, for
          example to unlock system hard disks or cryptographic
          certificates. Unless this option is specified and the
          command is invoked from a terminal,
          <command>systemctl</command> will query the user on the
          terminal for the necessary secrets. Use this option to
          switch this behavior off. In this case, the password must be
          supplied by some other means (for example graphical password
          agents) or the service might fail. This also disables
          querying the user for authentication for privileged
          operations.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--kill-who=</option></term>

        <listitem>
          <para>When used with <command>kill</command>, choose which
          processes to send a signal to. Must be one of
          <option>main</option>, <option>control</option> or
          <option>all</option> to select whether to kill only the main
          process, the control process or all processes of the
          unit. The main process of the unit is the one that defines
          the life-time of it. A control process of a unit is one that
          is invoked by the manager to induce state changes of it. For
          example, all processes started due to the
          <varname>ExecStartPre=</varname>,
          <varname>ExecStop=</varname> or
          <varname>ExecReload=</varname> settings of service units are
          control processes. Note that there is only one control
          process per unit at a time, as only one state change is
          executed at a time. For services of type
          <varname>Type=forking</varname>, the initial process started
          by the manager for <varname>ExecStart=</varname> is a
          control process, while the process ultimately forked off by
          that one is then considered the main process of the unit (if
          it can be determined). This is different for service units
          of other types, where the process forked off by the manager
          for <varname>ExecStart=</varname> is always the main process
          itself. A service unit consists of zero or one main process,
          zero or one control process plus any number of additional
          processes. Not all unit types manage processes of these
          types however. For example, for mount units, control processes
          are defined (which are the invocations of
          <filename>&MOUNT_PATH;</filename> and
          <filename>&UMOUNT_PATH;</filename>), but no main process
          is defined. If omitted, defaults to
          <option>all</option>.</para>
        </listitem>

      </varlistentry>

      <varlistentry>
        <term><option>-s</option></term>
        <term><option>--signal=</option></term>

        <listitem>
          <para>When used with <command>kill</command>, choose which
          signal to send to selected processes. Must be one of the
          well known signal specifiers such as <constant>SIGTERM</constant>, <constant>SIGINT</constant> or
          <constant>SIGSTOP</constant>. If omitted, defaults to
          <option>SIGTERM</option>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-f</option></term>
        <term><option>--force</option></term>

        <listitem>
          <para>When used with <command>enable</command>, overwrite
          any existing conflicting symlinks.</para>

          <para>When used with <command>halt</command>,
          <command>poweroff</command>, <command>reboot</command> or
          <command>kexec</command>, execute the selected operation
          without shutting down all units. However, all processes will
          be killed forcibly and all file systems are unmounted or
          remounted read-only. This is hence a drastic but relatively
          safe option to request an immediate reboot. If
          <option>--force</option> is specified twice for these
          operations, they will be executed immediately without
          terminating any processes or unmounting any file
          systems. Warning: specifying <option>--force</option> twice
          with any of these operations might result in data
          loss.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--message=</option></term>

        <listitem>
          <para>When used with <command>halt</command>,
          <command>poweroff</command>, <command>reboot</command> or
          <command>kexec</command>, set a short message explaining the reason
          for the operation. The message will be logged together with the
          default shutdown message.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--now</option></term>

        <listitem>
          <para>When used with <command>enable</command>, the units
          will also be started. When used with <command>disable</command> or
          <command>mask</command>, the units will also be stopped. The start
          or stop operation is only carried out when the respective enable or
          disable operation has been successful.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--root=</option></term>

        <listitem>
          <para>When used with
          <command>enable</command>/<command>disable</command>/<command>is-enabled</command>
          (and related commands), use alternative root path when
          looking for unit files.</para>
        </listitem>

      </varlistentry>

      <varlistentry>
        <term><option>--runtime</option></term>

        <listitem>
          <para>When used with <command>enable</command>,
          <command>disable</command>, <command>edit</command>,
          (and related commands), make changes only temporarily, so
          that they are lost on the next reboot. This will have the
          effect that changes are not made in subdirectories of
          <filename>/etc</filename> but in <filename>/run</filename>,
          with identical immediate effects, however, since the latter
          is lost on reboot, the changes are lost too.</para>

          <para>Similarly, when used with
          <command>set-property</command>, make changes only
          temporarily, so that they are lost on the next
          reboot.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--preset-mode=</option></term>

        <listitem>
          <para>Takes one of <literal>full</literal> (the default),
          <literal>enable-only</literal>,
          <literal>disable-only</literal>. When used with the
          <command>preset</command> or <command>preset-all</command>
          commands, controls whether units shall be disabled and
          enabled according to the preset rules, or only enabled, or
          only disabled.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-n</option></term>
        <term><option>--lines=</option></term>

        <listitem>
          <para>When used with <command>status</command>, controls the
          number of journal lines to show, counting from the most
          recent ones. Takes a positive integer argument. Defaults to
          10.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-o</option></term>
        <term><option>--output=</option></term>

        <listitem>
          <para>When used with <command>status</command>, controls the
          formatting of the journal entries that are shown. For the
          available choices, see
          <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
          Defaults to <literal>short</literal>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--firmware-setup</option></term>

        <listitem>
          <para>When used with the <command>reboot</command> command,
          indicate to the system's firmware to boot into setup
          mode. Note that this is currently only supported on some EFI
          systems and only if the system was booted in EFI
          mode.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--plain</option></term>

        <listitem>
          <para>When used with <command>list-dependencies</command>,
          the output is printed as a list instead of a tree.</para>
        </listitem>
      </varlistentry>

      <xi:include href="user-system-options.xml" xpointer="host" />
      <xi:include href="user-system-options.xml" xpointer="machine" />

      <xi:include href="standard-options.xml" xpointer="no-pager" />
      <xi:include href="standard-options.xml" xpointer="no-legend" />
      <xi:include href="standard-options.xml" xpointer="help" />
      <xi:include href="standard-options.xml" xpointer="version" />
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Commands</title>

    <para>The following commands are understood:</para>

    <refsect2>
      <title>Unit Commands</title>

      <variablelist>
        <varlistentry>
          <term><command>list-units <optional><replaceable>PATTERN</replaceable>...</optional></command></term>

          <listitem>
            <para>List known units (subject to limitations specified
            with <option>-t</option>). If one or more
            <replaceable>PATTERN</replaceable>s are specified, only
            units matching one of them are shown.</para>

            <para>This is the default command.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>list-sockets <optional><replaceable>PATTERN</replaceable>...</optional></command></term>

          <listitem>
            <para>List socket units ordered by listening address.
            If one or more <replaceable>PATTERN</replaceable>s are
            specified, only socket units matching one of them are
            shown. Produces output similar to
            <programlisting>
LISTEN           UNIT                        ACTIVATES
/dev/initctl     systemd-initctl.socket      systemd-initctl.service
...
[::]:22          sshd.socket                 sshd.service
kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service

5 sockets listed.</programlisting>
            Note: because the addresses might contains spaces, this output
            is not suitable for programmatic consumption.
            </para>

            <para>See also the options <option>--show-types</option>,
            <option>--all</option>, and <option>--state=</option>.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>list-timers <optional><replaceable>PATTERN</replaceable>...</optional></command></term>

          <listitem>
            <para>List timer units ordered by the time they elapse
            next. If one or more <replaceable>PATTERN</replaceable>s
            are specified, only units matching one of them are shown.
            </para>

            <para>See also the options <option>--all</option> and
            <option>--state=</option>.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>start <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Start (activate) one or more units specified on the
            command line.</para>

            <para>Note that glob patterns operate on a list of currently
            loaded units. Units which are not active and are not in a
            failed state usually are not loaded, and would not be
            matched by any pattern. In addition, in case of
            instantiated units, systemd is often unaware of the
            instance name until the instance has been started. Therefore,
            using glob patterns with <command>start</command>
            has limited usefulness.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>stop <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Stop (deactivate) one or more units specified on the
            command line.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>reload <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Asks all units listed on the command line to reload
            their configuration. Note that this will reload the
            service-specific configuration, not the unit configuration
            file of systemd. If you want systemd to reload the
            configuration file of a unit, use the
            <command>daemon-reload</command> command. In other words:
            for the example case of Apache, this will reload Apache's
            <filename>httpd.conf</filename> in the web server, not the
            <filename>apache.service</filename> systemd unit
            file.</para>

            <para>This command should not be confused with the
            <command>daemon-reload</command> command.</para>
          </listitem>

        </varlistentry>
        <varlistentry>
          <term><command>restart <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Restart one or more units specified on the command
            line. If the units are not running yet, they will be
            started.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>try-restart <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Restart one or more units specified on the command
            line if the units are running. This does nothing if units are not
            running.  Note that, for compatibility with Red Hat init
            scripts, <command>condrestart</command> is equivalent to this
            command.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>reload-or-restart <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Reload one or more units if they support it. If not,
            restart them instead. If the units are not running yet, they
            will be started.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>reload-or-try-restart <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Reload one or more units if they support it. If not,
            restart them instead. This does nothing if the units are not
            running. Note that, for compatibility with SysV init scripts,
            <command>force-reload</command> is equivalent to this
            command.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>isolate <replaceable>NAME</replaceable></command></term>

          <listitem>
            <para>Start the unit specified on the command line and its
            dependencies and stop all others. If a unit name with no
            extension is given, an extension of
            <literal>.target</literal> will be assumed.</para>

            <para>This is similar to changing the runlevel in a
            traditional init system. The <command>isolate</command>
            command will immediately stop processes that are not enabled
            in the new unit, possibly including the graphical
            environment or terminal you are currently using.</para>

            <para>Note that this is allowed only on units where
            <option>AllowIsolate=</option> is enabled. See
            <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
            for details.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>kill <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Send a signal to one or more processes of the
            unit. Use <option>--kill-who=</option> to select which
            process to kill. Use <option>--signal=</option> to select
            the signal to send.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>is-active <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Check whether any of the specified units are active
            (i.e. running). Returns an exit code
            <constant>0</constant> if at least one is active, or
            non-zero otherwise. Unless <option>--quiet</option> is
            specified, this will also print the current unit state to
            standard output.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>is-failed <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Check whether any of the specified units are in a
            "failed" state. Returns an exit code
            <constant>0</constant> if at least one has failed,
            non-zero otherwise. Unless <option>--quiet</option> is
            specified, this will also print the current unit state to
            standard output.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>status</command> <optional><replaceable>PATTERN</replaceable>...|<replaceable>PID</replaceable>...]</optional></term>

          <listitem>
            <para>Show terse runtime status information about one or
            more units, followed by most recent log data from the
            journal. If no units are specified, show system status. If
            combined with <option>--all</option>, also show the status of
            all units (subject to limitations specified with
            <option>-t</option>). If a PID is passed, show information
            about the unit the process belongs to.</para>

            <para>This function is intended to generate human-readable
            output. If you are looking for computer-parsable output,
            use <command>show</command> instead. By default this
            function only shows 10 lines of output and ellipsizes
            lines to fit in the terminal window. This can be changes
            with <option>--lines</option> and <option>--full</option>,
            see above. In addition, <command>journalctl
            --unit=<replaceable>NAME</replaceable></command> or
            <command>journalctl
            --user-unit=<replaceable>NAME</replaceable></command> use
            a similar filter for messages and might be more
            convenient.
            </para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>show</command> <optional><replaceable>PATTERN</replaceable>...|<replaceable>JOB</replaceable>...</optional></term>

          <listitem>
            <para>Show properties of one or more units, jobs, or the
            manager itself. If no argument is specified, properties of
            the manager will be shown. If a unit name is specified,
            properties of the unit is shown, and if a job id is
            specified, properties of the job is shown. By default, empty
            properties are suppressed. Use <option>--all</option> to
            show those too. To select specific properties to show, use
            <option>--property=</option>. This command is intended to be
            used whenever computer-parsable output is required. Use
            <command>status</command> if you are looking for formatted
            human-readable output.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>cat <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Show backing files of one or more units. Prints the
            "fragment" and "drop-ins" (source files) of units. Each
            file is preceded by a comment which includes the file
            name.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>set-property <replaceable>NAME</replaceable> <replaceable>ASSIGNMENT</replaceable>...</command></term>

          <listitem>
            <para>Set the specified unit properties at runtime where
            this is supported. This allows changing configuration
            parameter properties such as resource control settings at
            runtime. Not all properties may be changed at runtime, but
            many resource control settings (primarily those in
            <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>)
            may. The changes are applied instantly, and stored on disk
            for future boots, unless <option>--runtime</option> is
            passed, in which case the settings only apply until the
            next reboot. The syntax of the property assignment follows
            closely the syntax of assignments in unit files.</para>

            <para>Example: <command>systemctl set-property foobar.service CPUShares=777</command></para>

            <para>Note that this command allows changing multiple
            properties at the same time, which is preferable over
            setting them individually. Like unit file configuration
            settings, assigning the empty list to list parameters will
            reset the list.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>help <replaceable>PATTERN</replaceable>...|<replaceable>PID</replaceable>...</command></term>

          <listitem>
            <para>Show manual pages for one or more units, if
            available. If a PID is given, the manual pages for the unit
            the process belongs to are shown.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>reset-failed [<replaceable>PATTERN</replaceable>...]</command></term>

          <listitem>
            <para>Reset the <literal>failed</literal> state of the
            specified units, or if no unit name is passed, reset the state of all
            units. When a unit fails in some way (i.e. process exiting
            with non-zero error code, terminating abnormally or timing
            out), it will automatically enter the
            <literal>failed</literal> state and its exit code and status
            is recorded for introspection by the administrator until the
            service is restarted or reset with this command.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term>
            <command>list-dependencies</command>
            <optional><replaceable>NAME</replaceable></optional>
          </term>

          <listitem>
            <para>Shows units required and wanted by the specified
            unit. This recursively lists units following the
            <varname>Requires=</varname>,
            <varname>RequiresOverridable=</varname>,
            <varname>Requisite=</varname>,
            <varname>RequisiteOverridable=</varname>,
            <varname>Wants=</varname>, <varname>BindsTo=</varname>
            dependencies. If no unit is specified,
            <filename>default.target</filename> is implied.</para>

            <para>By default, only target units are recursively
            expanded. When <option>--all</option> is passed, all other
            units are recursively expanded as well.</para>

            <para>Options <option>--reverse</option>,
            <option>--after</option>, <option>--before</option>
            may be used to change what types of dependencies
            are shown.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </refsect2>

    <refsect2>
      <title>Unit File Commands</title>

      <variablelist>
        <varlistentry>
          <term><command>list-unit-files <optional><replaceable>PATTERN...</replaceable></optional></command></term>

          <listitem>
            <para>List installed unit files. If one or more
            <replaceable>PATTERN</replaceable>s are specified, only
            units whose filename (just the last component of the path)
            matches one of them are shown.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>enable <replaceable>NAME</replaceable>...</command></term>

          <listitem>
            <para>Enable one or more unit files or unit file instances,
            as specified on the command line. This will create a number
            of symlinks as encoded in the <literal>[Install]</literal>
            sections of the unit files. After the symlinks have been
            created, the systemd configuration is reloaded (in a way that
            is equivalent to <command>daemon-reload</command>) to ensure
            the changes are taken into account immediately. Note that
            this does <emphasis>not</emphasis> have the effect of also
            starting any of the units being enabled. If this
            is desired, either <option>--now</option> should be used
            together with this command, or an additional <command>start</command>
            command must be invoked for the unit. Also note that in case of
            instance enablement, symlinks named the same as instances
            are created in the install location, however they all point to the
            same template unit file.</para>

            <para>This command will print the actions executed. This
            output may be suppressed by passing <option>--quiet</option>.
            </para>

            <para>Note that this operation creates only the suggested
            symlinks for the units. While this command is the
            recommended way to manipulate the unit configuration
            directory, the administrator is free to make additional
            changes manually by placing or removing symlinks in the
            directory. This is particularly useful to create
            configurations that deviate from the suggested default
            installation. In this case, the administrator must make sure
            to invoke <command>daemon-reload</command> manually as
            necessary to ensure the changes are taken into account.
            </para>

            <para>Enabling units should not be confused with starting
            (activating) units, as done by the <command>start</command>
            command. Enabling and starting units is orthogonal: units
            may be enabled without being started and started without
            being enabled. Enabling simply hooks the unit into various
            suggested places (for example, so that the unit is
            automatically started on boot or when a particular kind of
            hardware is plugged in). Starting actually spawns the daemon
            process (in case of service units), or binds the socket (in
            case of socket units), and so on.</para>

            <para>Depending on whether <option>--system</option>,
            <option>--user</option>, <option>--runtime</option>,
            or <option>--global</option> is specified, this enables the unit
            for the system, for the calling user only, for only this boot of
            the system, or for all future logins of all users, or only this
            boot.  Note that in the last case, no systemd daemon
            configuration is reloaded.</para>

            <para>Using <command>enable</command> on masked units
            results in an error.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>disable <replaceable>NAME</replaceable>...</command></term>

          <listitem>
            <para>Disables one or more units. This removes all symlinks
            to the specified unit files from the unit configuration
            directory, and hence undoes the changes made by
            <command>enable</command>. Note however that this removes
            all symlinks to the unit files (i.e. including manual
            additions), not just those actually created by
            <command>enable</command>. This call implicitly reloads the
            systemd daemon configuration after completing the disabling
            of the units. Note that this command does not implicitly
            stop the units that are being disabled. If this is desired, either
            <option>--now</option> should be used together with this command, or
            an additional <command>stop</command> command should be executed
            afterwards.</para>

            <para>This command will print the actions executed. This
            output may be suppressed by passing <option>--quiet</option>.
            </para>

            <para>This command honors <option>--system</option>,
            <option>--user</option>, <option>--runtime</option> and
            <option>--global</option> in a similar way as
            <command>enable</command>.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>reenable <replaceable>NAME</replaceable>...</command></term>

          <listitem>
            <para>Reenable one or more unit files, as specified on the
            command line. This is a combination of
            <command>disable</command> and <command>enable</command> and
            is useful to reset the symlinks a unit is enabled with to
            the defaults configured in the <literal>[Install]</literal>
            section of the unit file.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>preset <replaceable>NAME</replaceable>...</command></term>

          <listitem>
            <para>Reset one or more unit files, as specified on the
            command line, to the defaults configured in the preset
            policy files. This has the same effect as
            <command>disable</command> or <command>enable</command>,
            depending how the unit is listed in the preset files.</para>

            <para>Use <option>--preset-mode=</option> to control
            whether units shall be enabled and disabled, or only
            enabled, or only disabled.</para>

            <para>For more information on the preset policy format,
            see
            <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
            For more information on the concept of presets, please
            consult the <ulink
            url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>
            document.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>preset-all</command></term>

          <listitem>
            <para>Resets all installed unit files to the defaults
            configured in the preset policy file (see above).</para>

            <para>Use <option>--preset-mode=</option> to control
            whether units shall be enabled and disabled, or only
            enabled, or only disabled.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>is-enabled <replaceable>NAME</replaceable>...</command></term>

          <listitem>
            <para>Checks whether any of the specified unit files are
            enabled (as with <command>enable</command>). Returns an
            exit code of 0 if at least one is enabled, non-zero
            otherwise. Prints the current enable status (see table).
            To suppress this output, use <option>--quiet</option>.
            </para>

            <table>
              <title>
                <command>is-enabled</command> output
              </title>

              <tgroup cols='3'>
                <thead>
                  <row>
                    <entry>Printed string</entry>
                    <entry>Meaning</entry>
                    <entry>Return value</entry>
                  </row>
                </thead>
                <tbody>
                  <row>
                    <entry><literal>enabled</literal></entry>
                    <entry morerows='1'>Enabled through a symlink in <filename>.wants</filename> directory (permanently or just in <filename>/run</filename>).</entry>
                    <entry morerows='1'>0</entry>
                  </row>
                  <row>
                    <entry><literal>enabled-runtime</literal></entry>
                  </row>
                  <row>
                    <entry><literal>linked</literal></entry>
                    <entry morerows='1'>Made available through a symlink to the unit file (permanently or just in <filename>/run</filename>).</entry>
                    <entry morerows='1'>1</entry>
                  </row>
                  <row>
                    <entry><literal>linked-runtime</literal></entry>
                  </row>
                  <row>
                    <entry><literal>masked</literal></entry>
                    <entry morerows='1'>Disabled entirely (permanently or just in <filename>/run</filename>).</entry>
                    <entry morerows='1'>1</entry>
                  </row>
                  <row>
                    <entry><literal>masked-runtime</literal></entry>
                  </row>
                  <row>
                    <entry><literal>static</literal></entry>
                    <entry>Unit file is not enabled, and has no provisions for enabling in the <literal>[Install]</literal> section.</entry>
                    <entry>0</entry>
                  </row>
                  <row>
                    <entry><literal>indirect</literal></entry>
                    <entry>Unit file itself is not enabled, but it has a non-empty <varname>Also=</varname> setting in the <literal>[Install]</literal> section, listing other unit files that might be enabled.</entry>
                    <entry>0</entry>
                  </row>
                  <row>
                    <entry><literal>disabled</literal></entry>
                    <entry>Unit file is not enabled.</entry>
                    <entry>1</entry>
                  </row>
                </tbody>
              </tgroup>
            </table>

          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>mask <replaceable>NAME</replaceable>...</command></term>

          <listitem>
            <para>Mask one or more unit files, as specified on the
            command line. This will link these units to
            <filename>/dev/null</filename>, making it impossible to
            start them. This is a stronger version of
            <command>disable</command>, since it prohibits all kinds of
            activation of the unit, including enablement and manual
            activation. Use this option with care. This honors the
            <option>--runtime</option> option to only mask temporarily
            until the next reboot of the system. The <option>--now</option>
            option can be used to ensure that the units are also stopped.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>unmask <replaceable>NAME</replaceable>...</command></term>

          <listitem>
            <para>Unmask one or more unit files, as specified on the
            command line. This will undo the effect of
            <command>mask</command>.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>link <replaceable>FILENAME</replaceable>...</command></term>

          <listitem>
            <para>Link a unit file that is not in the unit file search
            paths into the unit file search path. This requires an
            absolute path to a unit file. The effect of this can be
            undone with <command>disable</command>. The effect of this
            command is that a unit file is available for
            <command>start</command> and other commands although it
            is not installed directly in the unit search path.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>add-wants <replaceable>TARGET</replaceable>
          <replaceable>NAME</replaceable>...</command></term>
          <term><command>add-requires <replaceable>TARGET</replaceable>
          <replaceable>NAME</replaceable>...</command></term>

          <listitem>
            <para>Adds <literal>Wants=</literal> or <literal>Requires=</literal>
            dependency, respectively, to the specified
            <replaceable>TARGET</replaceable> for one or more units. </para>

            <para>This command honors <option>--system</option>,
            <option>--user</option>, <option>--runtime</option> and
            <option>--global</option> in a similar way as
            <command>enable</command>.</para>

          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>edit <replaceable>NAME</replaceable>...</command></term>

          <listitem>
            <para>Edit a drop-in snippet or a whole replacement file if
            <option>--full</option> is specified, to extend or override the
            specified unit.</para>

            <para>Depending on whether <option>--system</option> (the default),
            <option>--user</option>, or <option>--global</option> is specified,
            this creates a drop-in file for each unit either for the system,
            for the calling user or for all futures logins of all users. Then,
            the editor (see the "Environment" section below) is invoked on
            temporary files which will be written to the real location if the
            editor exits successfully.</para>

            <para>If <option>--full</option> is specified, this will copy the
            original units instead of creating drop-in files.</para>

            <para>If <option>--runtime</option> is specified, the changes will
            be made temporarily in <filename>/run</filename> and they will be
            lost on the next reboot.</para>

            <para>If the temporary file is empty upon exit the modification of
            the related unit is canceled</para>

            <para>After the units have been edited, systemd configuration is
            reloaded (in a way that is equivalent to <command>daemon-reload</command>).
            </para>

            <para>Note that this command cannot be used to remotely edit units
            and that you cannot temporarily edit units which are in
            <filename>/etc</filename> since they take precedence over
            <filename>/run</filename>.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>get-default</command></term>

          <listitem>
            <para>Return the default target to boot into. This returns
            the target unit name <filename>default.target</filename>
            is aliased (symlinked) to.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>set-default <replaceable>NAME</replaceable></command></term>

          <listitem>
            <para>Set the default target to boot into. This sets
            (symlinks) the <filename>default.target</filename> alias
            to the given target unit.</para>
          </listitem>
        </varlistentry>

      </variablelist>
    </refsect2>

    <refsect2>
      <title>Machine Commands</title>

      <variablelist>
        <varlistentry>
          <term><command>list-machines <optional><replaceable>PATTERN</replaceable>...</optional></command></term>

          <listitem>
            <para>List the host and all running local containers with
            their state. If one or more
            <replaceable>PATTERN</replaceable>s are specified, only
            containers matching one of them are shown.
            </para>
          </listitem>
        </varlistentry>
      </variablelist>
    </refsect2>

    <refsect2>
      <title>Job Commands</title>

      <variablelist>
        <varlistentry>
          <term><command>list-jobs <optional><replaceable>PATTERN...</replaceable></optional></command></term>

          <listitem>
            <para>List jobs that are in progress. If one or more
            <replaceable>PATTERN</replaceable>s are specified, only
            jobs for units matching one of them are shown.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>cancel <replaceable>JOB</replaceable>...</command></term>

          <listitem>
            <para>Cancel one or more jobs specified on the command line
            by their numeric job IDs. If no job ID is specified, cancel
            all pending jobs.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </refsect2>

    <refsect2>
      <title>Snapshot Commands</title>

      <variablelist>
        <varlistentry>
          <term><command>snapshot <optional><replaceable>NAME</replaceable></optional></command></term>

          <listitem>
            <para>Create a snapshot. If a snapshot name is specified,
            the new snapshot will be named after it. If none is
            specified, an automatic snapshot name is generated. In
            either case, the snapshot name used is printed to standard
            output, unless <option>--quiet</option> is specified.
            </para>

            <para>A snapshot refers to a saved state of the systemd
            manager. It is implemented itself as a unit that is
            generated dynamically with this command and has dependencies
            on all units active at the time. At a later time, the user
            may return to this state by using the
            <command>isolate</command> command on the snapshot unit.
            </para>

            <para>Snapshots are only useful for saving and restoring
            which units are running or are stopped, they do not
            save/restore any other state. Snapshots are dynamic and lost
            on reboot.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>delete <replaceable>PATTERN</replaceable>...</command></term>

          <listitem>
            <para>Remove a snapshot previously created with
            <command>snapshot</command>.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </refsect2>

    <refsect2>
      <title>Environment Commands</title>

      <variablelist>
        <varlistentry>
          <term><command>show-environment</command></term>

          <listitem>
            <para>Dump the systemd manager environment block. The
            environment block will be dumped in straight-forward form
            suitable for sourcing into a shell script. This environment
            block will be passed to all processes the manager
            spawns.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>set-environment <replaceable>VARIABLE=VALUE</replaceable>...</command></term>

          <listitem>
            <para>Set one or more systemd manager environment variables,
            as specified on the command line.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>unset-environment <replaceable>VARIABLE</replaceable>...</command></term>

          <listitem>
            <para>Unset one or more systemd manager environment
            variables. If only a variable name is specified, it will be
            removed regardless of its value. If a variable and a value
            are specified, the variable is only removed if it has the
            specified value.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term>
            <command>import-environment</command>
            <optional><replaceable>VARIABLE...</replaceable></optional>
          </term>

          <listitem>
            <para>Import all, one or more environment variables set on
            the client into the systemd manager environment block. If
            no arguments are passed, the entire environment block is
            imported. Otherwise, a list of one or more environment
            variable names should be passed, whose client-side values
            are then imported into the manager's environment
            block.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </refsect2>

    <refsect2>
      <title>Manager Lifecycle Commands</title>

      <variablelist>
        <varlistentry>
          <term><command>daemon-reload</command></term>

          <listitem>
            <para>Reload systemd manager configuration. This will
            rerun all generators (see
            <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>),
            reload all unit files, and recreate the entire dependency
            tree. While the daemon is being reloaded, all sockets
            systemd listens on behalf of user configuration will stay
            accessible.</para>

            <para>This command should not be confused with the
            <command>reload</command> command.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>daemon-reexec</command></term>

          <listitem>
            <para>Reexecute the systemd manager. This will serialize the
            manager state, reexecute the process and deserialize the
            state again. This command is of little use except for
            debugging and package upgrades. Sometimes, it might be
            helpful as a heavy-weight <command>daemon-reload</command>.
            While the daemon is being reexecuted, all sockets systemd listening
            on behalf of user configuration will stay accessible.
            </para>
          </listitem>
        </varlistentry>
      </variablelist>
    </refsect2>

    <refsect2>
      <title>System Commands</title>

      <variablelist>
        <varlistentry>
          <term><command>is-system-running</command></term>

          <listitem>
            <para>Checks whether the system is operational. This
            returns success when the system is fully up and running,
            meaning not in startup, shutdown or maintenance
            mode. Failure is returned otherwise. In addition, the
            current state is printed in a short string to standard
            output, see table below. Use <option>--quiet</option> to
            suppress this output.</para>

            <table>
              <title>Manager Operational States</title>
              <tgroup cols='2'>
                <colspec colname='name' />
                <colspec colname='description' />
                <thead>
                  <row>
                    <entry>Name</entry>
                    <entry>Description</entry>
                  </row>
                </thead>
                <tbody>
                  <row>
                    <entry><varname>initializing</varname></entry>
                    <entry><para>Early bootup, before
                    <filename>basic.target</filename> is reached
                    or the <varname>maintenance</varname> state entered.
                    </para></entry>
                  </row>
                  <row>
                    <entry><varname>starting</varname></entry>
                    <entry><para>Late bootup, before the job queue
                    becomes idle for the first time, or one of the
                    rescue targets are reached.</para></entry>
                  </row>
                  <row>
                    <entry><varname>running</varname></entry>
                    <entry><para>The system is fully
                    operational.</para></entry>
                  </row>
                  <row>
                    <entry><varname>degraded</varname></entry>
                    <entry><para>The system is operational but one or more
                    units failed.</para></entry>
                  </row>
                  <row>
                    <entry><varname>maintenance</varname></entry>
                    <entry><para>The rescue or emergency target is
                    active.</para></entry>
                  </row>
                  <row>
                    <entry><varname>stopping</varname></entry>
                    <entry><para>The manager is shutting
                    down.</para></entry>
                  </row>
                </tbody>
              </tgroup>
            </table>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>default</command></term>

          <listitem>
            <para>Enter default mode. This is mostly equivalent to
            <command>isolate default.target</command>.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>rescue</command></term>

          <listitem>
            <para>Enter rescue mode. This is mostly equivalent to
            <command>isolate rescue.target</command>, but also prints a
            wall message to all users.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>emergency</command></term>

          <listitem>
            <para>Enter emergency mode. This is mostly equivalent to
            <command>isolate emergency.target</command>, but also prints
            a wall message to all users.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>halt</command></term>

          <listitem>
            <para>Shut down and halt the system. This is mostly equivalent to
            <command>start halt.target --job-mode=replace-irreversibly</command>, but also
            prints a wall message to all users.  If combined with
            <option>--force</option>, shutdown of all running services is
            skipped, however all processes are killed and all file
            systems are unmounted or mounted read-only, immediately
            followed by the system halt.  If <option>--force</option> is
            specified twice, the operation is immediately executed
            without terminating any processes or unmounting any file
            systems. This may result in data loss.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>poweroff</command></term>

          <listitem>
            <para>Shut down and power-off the system. This is mostly
            equivalent to <command>start poweroff.target --job-mode=replace-irreversibly</command>,
            but also prints a wall message to all users. If combined with
            <option>--force</option>, shutdown of all running services is
            skipped, however all processes are killed and all file
            systems are unmounted or mounted read-only, immediately
            followed by the powering off. If <option>--force</option> is
            specified twice, the operation is immediately executed
            without terminating any processes or unmounting any file
            systems. This may result in data loss.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><command>reboot <optional><replaceable>arg</replaceable></optional></command></term>

          <listitem>
            <para>Shut down and reboot the system. This is mostly
            equivalent to <command>start reboot.target --job-mode=replace-irreversibly</command>,
            but also prints a wall message to all users. If combined with
            <option>--force</option>, shutdown of all running services is
            skipped, however all processes are killed and all file
            systems are unmounted or mounted read-only, immediately
            followed by the reboot. If <option>--force</option> is
            specified twice, the operation is immediately executed
            without terminating any processes or unmounting any file
            systems. This may result in data loss.</para>

            <para>If the optional argument
            <replaceable>arg</replaceable> is given, it will be passed
            as the optional argument to the
            <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
            system call. The value is architecture and firmware
            specific. As an example, <literal>recovery</literal> might
            be used to trigger system recovery, and
            <literal>fota</literal> might be used to trigger a
            <quote>firmware over the air</quote> update.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>kexec</command></term>

          <listitem>
            <para>Shut down and reboot the system via kexec. This is
            mostly equivalent to <command>start kexec.target --job-mode=replace-irreversibly</command>,
            but also prints a wall message to all users. If combined
            with <option>--force</option>, shutdown of all running
            services is skipped, however all processes are killed and
            all file systems are unmounted or mounted read-only,
            immediately followed by the reboot.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>exit</command></term>

          <listitem>
            <para>Ask the systemd manager to quit. This is only
            supported for user service managers (i.e. in conjunction
            with the <option>--user</option> option) and will fail
            otherwise.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>switch-root <replaceable>ROOT</replaceable> <optional><replaceable>INIT</replaceable></optional></command></term>

          <listitem>
            <para>Switches to a different root directory and executes a
            new system manager process below it. This is intended for
            usage in initial RAM disks ("initrd"), and will transition
            from the initrd's system manager process (a.k.a "init"
            process) to the main system manager process. This call takes two
            arguments: the directory that is to become the new root directory, and
            the path to the new system manager binary below it to
            execute as PID 1. If the latter is omitted or the empty
            string, a systemd binary will automatically be searched for
            and used as init. If the system manager path is omitted or
            equal to the empty string, the state of the initrd's system
            manager process is passed to the main system manager, which
            allows later introspection of the state of the services
            involved in the initrd boot.</para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>suspend</command></term>

          <listitem>
            <para>Suspend the system. This will trigger activation of
            the special <filename>suspend.target</filename> target.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>hibernate</command></term>

          <listitem>
            <para>Hibernate the system. This will trigger activation of
            the special <filename>hibernate.target</filename> target.
            </para>
          </listitem>
        </varlistentry>

        <varlistentry>
          <term><command>hybrid-sleep</command></term>

          <listitem>
            <para>Hibernate and suspend the system. This will trigger
            activation of the special
            <filename>hybrid-sleep.target</filename> target.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </refsect2>

    <refsect2>
      <title>Parameter Syntax</title>

      <para>Unit commands listed above take either a single unit name
      (designated as <replaceable>NAME</replaceable>), or multiple
      unit specifications (designated as
      <replaceable>PATTERN</replaceable>...). In the first case, the
      unit name with or without a suffix must be given. If the suffix
      is not specified, systemctl will append a suitable suffix,
      <literal>.service</literal> by default, and a type-specific
      suffix in case of commands which operate only on specific unit
      types. For example,
      <programlisting># systemctl start sshd</programlisting> and
      <programlisting># systemctl start sshd.service</programlisting>
      are equivalent, as are
      <programlisting># systemctl isolate default</programlisting>
      and
      <programlisting># systemctl isolate default.target</programlisting>
      Note that (absolute) paths to device nodes are automatically
      converted to device unit names, and other (absolute) paths to
      mount unit names.
      <programlisting># systemctl status /dev/sda
# systemctl status /home</programlisting>
      are equivalent to:
      <programlisting># systemctl status dev-sda.device
# systemctl status home.mount</programlisting>
      In the second case, shell-style globs will be matched against
      currently loaded units; literal unit names, with or without
      a suffix, will be treated as in the first case. This means that
      literal unit names always refer to exactly one unit, but globs
      may match zero units and this is not considered an error.</para>

      <para>Glob patterns use
      <citerefentry project='man-pages'><refentrytitle>fnmatch</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      so normal shell-style globbing rules are used, and
      <literal>*</literal>, <literal>?</literal>,
      <literal>[]</literal> may be used. See
      <citerefentry project='man-pages'><refentrytitle>glob</refentrytitle><manvolnum>7</manvolnum></citerefentry>
      for more details. The patterns are matched against the names of
      currently loaded units, and patterns which do not match anything
      are silently skipped. For example:
      <programlisting># systemctl stop sshd@*.service</programlisting>
      will stop all <filename>sshd@.service</filename> instances.
      </para>

      <para>For unit file commands, the specified
      <replaceable>NAME</replaceable> should be the full name of the
      unit file, or the absolute path to the unit file:
      <programlisting># systemctl enable foo.service</programlisting>
      or
      <programlisting># systemctl link /path/to/foo.service</programlisting>
      </para>
    </refsect2>

  </refsect1>

  <refsect1>
    <title>Exit status</title>

    <para>On success, 0 is returned, a non-zero failure
    code otherwise.</para>
  </refsect1>

  <refsect1>
    <title>Environment</title>

    <variablelist class='environment-variables'>
      <varlistentry>
        <term><varname>$SYSTEMD_EDITOR</varname></term>

        <listitem><para>Editor to use when editing units; overrides
        <varname>$EDITOR</varname> and <varname>$VISUAL</varname>. If neither
        <varname>$SYSTEMD_EDITOR</varname> nor <varname>$EDITOR</varname> nor
        <varname>$VISUAL</varname> are present or if it is set to an empty
        string or if their execution failed, systemctl will try to execute well
        known editors in this order:
        <citerefentry project='die-net'><refentrytitle>editor</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
        <citerefentry project='die-net'><refentrytitle>nano</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
        <citerefentry project='die-net'><refentrytitle>vim</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
        <citerefentry project='die-net'><refentrytitle>vi</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
        </para></listitem>
      </varlistentry>
    </variablelist>
    <xi:include href="less-variables.xml" xpointer="pager"/>
    <xi:include href="less-variables.xml" xpointer="less"/>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
      <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
      <citerefentry project='man-pages'><refentrytitle>glob</refentrytitle><manvolnum>7</manvolnum></citerefentry>
    </para>
  </refsect1>

</refentry>