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<refentry id="systemd-install">

        <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 session manager</refpurpose>
        </refnamediv>

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

        <refsect1>
                <title>Description</title>

                <para><command>systemctl</command> may be used to
                introspect and control the state of the
                <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                system and session manager.</para>
        </refsect1>

        <refsect1>
                <title>Options</title>

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

                <variablelist>
                        <varlistentry>
                                <term><option>--help</option></term>
                                <term><option>-h</option></term>

                                <listitem><para>Prints a short help
                                text and exits.</para></listitem>
                        </varlistentry>

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

                                <listitem><para>When listing units,
                                limit display to certain unit
                                types. If not specified units of all
                                types will be shown. The argument
                                should be a unit type name such as
                                <option>service</option>,
                                <option>socket</option> and
                                similar.</para></listitem>
                        </varlistentry>

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

                                <listitem><para>When showing
                                unit/job/manager information, limit
                                display to certain property names. If
                                not specified all set properties are
                                shown. The argument should be a
                                property name, such as
                                <literal>MainPID</literal>.</para></listitem>
                        </varlistentry>

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

                                <listitem><para>When listing units,
                                show all units, regardless of their
                                state, including inactive units. When
                                showing unit/job/manager information,
                                show all properties regardless whether
                                they are set or not.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--fail</option></term>

                                <listitem><para>If the requested
                                operation conflicts with an existing
                                unfinished operation, fail the
                                command. If this is not specified the
                                requested operation will replace the
                                pending job if
                                necessary.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--order</option></term>
                                <term><option>--require</option></term>

                                <listitem><para>When used in
                                conjunction with the
                                <command>dot</command> command (see
                                below), selects which dependencies are
                                shown in the dependency graph. If
                                <option>--order</option> is passed
                                only dependencies of type
                                <varname>After=</varname> or
                                <varname>Before=</varname> are
                                shown. If <option>--require</option>
                                is passed only dependencies of type
                                <varname>Requires=</varname>,
                                <varname>RequiresOverridable=</varname>,
                                <varname>Requisite=</varname>,
                                <varname>RequisiteOverridable=</varname>,
                                <varname>Wants=</varname> and
                                <varname>Conflicts=</varname> are
                                shown. If neither is passed, shows
                                dependencies of all these
                                types.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--system</option></term>

                                <listitem><para>Talk to the systemd
                                system manager. (Default)</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--session</option></term>

                                <listitem><para>Talk to the systemd
                                session manager of the calling user.</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 it is completed. By passing this
				argument it is only verified and
				enqueued.</para></listitem> </varlistentry>

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

                                <listitem><para>Suppress output to
                                STDOUT for <command>snapshot</command>
                                and
                                <command>check</command>.</para></listitem>
                        </varlistentry>

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

                                <listitem><para>Don't send wall
                                message before
                                halt, power-off, reboot.</para></listitem>
                        </varlistentry>
                </variablelist>

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

                <variablelist>
                        <varlistentry>
                                <term><command>list-units</command></term>

                                <listitem><para>List known units.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>start [NAME...]</command></term>

                                <listitem><para>Start one or more
                                units specified on the command
                                line.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>stop [NAME...]</command></term>

                                <listitem><para>Stop one or more units
                                specified on the command
                                line.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>reload [NAME...]</command></term>

                                <listitem><para>Asks all services
                                whose units are listed on the command
                                line to reload their
                                configuration. Note that this will
                                reload the daemon configuration
                                itself, 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>
                                or <command>load</command>
                                commands.</para></listitem>

                        </varlistentry>
                        <varlistentry>
                                <term><command>restart [NAME...]</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 [NAME...]</command></term>

                                <listitem><para>Restart one or more
                                units specified on the command
                                line. If the units are not running yet
                                the operation will
                                fail.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>reload-or-restart [NAME...]</command></term>
                                <term><command>reload-or-try-restart [NAME...]</command></term>

                                <listitem><para>Reload one or more
                                units if they support it. If not
                                restart them
                                instead.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>isolate [NAME]</command></term>

                                <listitem><para>Start the unit
                                specified on the command line and its
                                dependencies and stop all
                                others.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>check [NAME...]</command></term>

                                <listitem><para>Check whether any of
                                the specified units is active
                                (i.e. running). Returns 0 if at least
                                one is active, non-zero
                                otherwise. Unless
                                <option>--quiet</option> is specified
                                this will also print the current unit
                                state to STDOUT.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>status [NAME...]</command></term>

                                <listitem><para>Show short status
                                information about one or more
                                units. This shows terse runtime
                                information about
                                units.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>show [NAME...|JOB...]</command></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.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><command>reset-maintenance [NAME...]</command></term>

                                <listitem><para>Reset maintenance
                                state of the specified units, or if no
                                unit name is passed 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
                                maintenance state and its exit codes
                                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>load [NAME...]</command></term>

                                <listitem><para>Load one or more units
                                specified on the command line. This
                                will simply load their configuration
                                from disk, but not start them. To
                                start them you need to use the
                                <command>start</command> command which
                                will implicitly load a unit that has
                                not been loaded yet. Note that systemd
                                garbage collects loaded units that are
                                not active or referenced by an active
                                unit. This means that units loaded
                                this way will usually not stay loaded
                                for long. Also note that this command
                                cannot be used to reload unit
                                configuration. Use the
                                <command>daemon-reload</command>
                                command for that. All in all, this
                                command is of little use except for
                                debugging.</para>
                                <para>This command should not be
                                confused with the
                                <command>daemon-reload</command> or
                                <command>reload</command>
                                commands.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>list-jobs</command></term>

                                <listitem><para>List jobs that are in progress.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>cancel [JOB...]</command></term>

                                <listitem><para>Cancel one or more
                                jobs specified on the command line by
                                their numeric job
                                IDs.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>clear-jobs</command></term>

                                <listitem><para>Cancel all jobs that are in progress.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>monitor</command></term>

                                <listitem><para>Monitor unit/job
                                changes. This is mostly useful for
                                debugging purposes and prints a line
                                each time systemd loads or unloads a
                                unit configuration file, or a unit
                                property changes.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>dump</command></term>

                                <listitem><para>Dump server
                                status. This will output a (usually
                                very long) human readable manager
                                status dump. Its format is subject to
                                change without notice and should not
                                be parsed by
                                applications.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>dot</command></term>

                                <listitem><para>Generate textual
                                dependency graph description in dot
                                format for further processing with the
                                GraphViz
                                <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                                tool. Use a command line like
                                <command>systemctl dot | dot -Tsvg >
                                systemd.svg</command> to generate a
                                graphical dependency tree. Unless
                                <option>--order</option> or
                                <option>--require</option> is passed
                                the generated graph will show both
                                ordering and requirement
                                dependencies.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>snapshot [NAME]</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 STDOUT, unless
                                <option>--quiet</option> is
                                specified.</para>

                                <para>A snapshot refers to a saved
                                state of the systemd manager. It is
                                implemented itself as 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></listitem>

                                <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>
                        </varlistentry>
                        <varlistentry>
                                <term><command>delete [NAME...]</command></term>

                                <listitem><para>Remove a snapshot
                                previously created with
                                <command>snapshot</command>.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>daemon-reload</command></term>

                                <listitem><para>Reload systemd manager
                                configuration. This will reload all
                                unit files and recreate the entire
                                dependency tree. While the daemon is
                                reloaded, all sockets systemd listens
                                on on behalf of user configuration will
                                stay accessible.</para> <para>This
                                command should not be confused with
                                the <command>load</command> or
                                <command>reload</command>
                                commands.</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 reexecuted all sockets
                                systemd listens on on behalf of user
                                configuration will stay
                                accessible.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>daemon-exit</command></term>

                                <listitem><para>Ask the systemd
                                manager to quit. This is only
                                supported for session managers
                                (i.e. in conjunction with the
                                <option>--session</option> option) and
                                will fail otherwise.</para></listitem>
                        </varlistentry>
                        <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 [NAME=VALUE...]</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 [NAME...]</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>halt</command></term>

                                <listitem><para>Shut down and halt the
                                system. This is mostly equivalent to
                                <command>start halt.target</command>
                                but also prints a wall message to all
                                users.</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</command> but also
                                prints a wall message to all
                                users.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>reboot</command></term>

                                <listitem><para>Shut down and
                                reboot the system. This is mostly
                                equivalent to <command>start
                                reboot.target</command> but also
                                prints a wall message to all
                                users.</para></listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><command>default</command></term>

                                <listitem><para>Enter default
                                mode. This is mostly equivalent to
                                <command>start
                                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>
                </variablelist>

        </refsect1>

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

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

        <refsect1>
                <title>See Also</title>
                <para>
                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                </para>
        </refsect1>

</refentry>