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2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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6 This file is part of systemd.
8 Copyright 2010 Lennart Poettering
10 systemd is free software; you can redistribute it and/or modify it
11 under the terms of the GNU Lesser General Public License as published by
12 the Free Software Foundation; either version 2.1 of the License, or
13 (at your option) any later version.
15 systemd is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public License
21 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 <refentry id="systemctl">
27 <title>systemctl</title>
28 <productname>systemd</productname>
32 <contrib>Developer</contrib>
33 <firstname>Lennart</firstname>
34 <surname>Poettering</surname>
35 <email>lennart@poettering.net</email>
41 <refentrytitle>systemctl</refentrytitle>
42 <manvolnum>1</manvolnum>
46 <refname>systemctl</refname>
47 <refpurpose>Control the systemd system and service manager</refpurpose>
52 <command>systemctl</command>
53 <arg choice="opt" rep="repeat">OPTIONS</arg>
54 <arg choice="plain">COMMAND</arg>
55 <arg choice="opt" rep="repeat">NAME</arg>
60 <title>Description</title>
62 <para><command>systemctl</command> may be used to
63 introspect and control the state of the
64 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
65 system and service manager.</para>
67 <para>For unit commands, the <replaceable>NAME</replaceable> represents full name of the unit.
69 systemctl start foo.service
71 For unit file commands, the <replaceable>NAME</replaceable> represents the full name of the unit file, or the absolute path to the unit file.
73 systemctl start /path/to/foo.service
75 While working with services/service files, <command>systemctl</command> implicitly appends the ".service" suffix when it is missing.
78 </programlisting></para>
82 <title>Options</title>
84 <para>The following options are understood:</para>
88 <term><option>-h</option></term>
89 <term><option>--help</option></term>
91 <listitem><para>Prints a short help
92 text and exits.</para></listitem>
96 <term><option>--version</option></term>
99 <para>Prints a short version string and exits.</para>
104 <term><option>-t</option></term>
105 <term><option>--type=</option></term>
108 <para>The argument should be a comma-separated list of unit
109 types such as <option>service</option> and
110 <option>socket</option>.
113 <para>If one of the arguments is a unit type, when listing
114 units, limit display to certain unit types. Otherwise, units
115 of all types will be shown.</para>
117 <para>As a special case, if one of the arguments is
118 <option>help</option>, a list of allowed values will be
119 printed and the program will exit.</para>
124 <term><option>--state=</option></term>
127 <para>The argument should be a comma-separated list of unit LOAD,
128 SUB, or ACTIVE states. When listing units, show only those
129 in specified states.</para>
134 <term><option>-p</option></term>
135 <term><option>--property=</option></term>
138 <para>When showing unit/job/manager properties with the
139 <command>show</command> command, limit display to certain
140 properties as specified as argument. If not specified, all
141 set properties are shown. The argument should be a
142 comma-separated list of property names, such as
143 <literal>MainPID</literal>. If specified more than once, all
144 properties with the specified names are shown.</para>
149 <term><option>-a</option></term>
150 <term><option>--all</option></term>
153 <para>When listing units, show all loaded units, regardless
154 of their state, including inactive units. When showing
155 unit/job/manager properties, show all properties regardless
156 whether they are set or not.</para>
157 <para>To list all units installed on the system, use the
158 <command>list-unit-files</command> command instead.</para>
163 <term><option>--reverse</option></term>
166 <para>Show reverse dependencies between units with
167 <command>list-dependencies</command>, i.e. units with
168 dependencies of type <varname>Wants=</varname> or
169 <varname>Requires=</varname> on the given unit.
175 <term><option>--after</option></term>
176 <term><option>--before</option></term>
179 <para>Show which units are started after or before
180 with <command>list-dependencies</command>, respectively.
186 <term><option>-l</option></term>
187 <term><option>--full</option></term>
190 <para>Do not ellipsize unit names, process tree entries, and
191 truncate unit descriptions in the output of
192 <command>list-units</command> and
193 <command>list-jobs</command>.</para>
198 <term><option>--show-types</option></term>
201 <para>When showing sockets, show the type of the socket.</para>
206 <term><option>--job-mode=</option></term>
209 <para>When queuing a new job, control how to deal with already
210 queued jobs. Takes one of <literal>fail</literal>,
211 <literal>replace</literal>,
212 <literal>replace-irreversibly</literal>,
213 <literal>isolate</literal>,
214 <literal>ignore-dependencies</literal>,
215 <literal>ignore-requirements</literal> or
216 <literal>flush</literal>. Defaults to
217 <literal>replace</literal>, except when the
218 <command>isolate</command> command is used which implies the
219 <literal>isolate</literal> job mode.</para>
221 <para>If <literal>fail</literal> is specified and a requested
222 operation conflicts with a pending job (more specifically:
223 causes an already pending start job to be reversed into a stop
224 job or vice versa), cause the operation to fail.</para>
226 <para>If <literal>replace</literal> (the default) is
227 specified, any conflicting pending job will be replaced, as
230 <para>If <literal>replace-irreversibly</literal> is specified,
231 operate like <literal>replace</literal>, but also mark the new
232 jobs as irreversible. This prevents future conflicting
233 transactions from replacing these jobs. The jobs can still be
234 cancelled using the <command>cancel</command> command.</para>
236 <para><literal>isolate</literal> is only valid for start
237 operations and causes all other units to be stopped when the
238 specified unit is started. This mode is always used when the
239 <command>isolate</command> command is used.</para>
241 <para><literal>flush</literal> will cause all queued jobs to
242 be canceled when the new job is enqueued.</para>
244 <para>If <literal>ignore-dependencies</literal> is specified,
245 then all unit dependencies are ignored for this new job and
246 the operation is executed immediately. If passed, no required
247 units of the unit passed will be pulled in, and no ordering
248 dependencies will be honored. This is mostly a debugging and
249 rescue tool for the administrator and should not be used by
252 <para><literal>ignore-requirements</literal> is similar to
253 <literal>ignore-dependencies</literal> but only causes the
254 requirement dependencies to be ignored, the ordering
255 dependencies will still be honoured.</para>
261 <term><option>-i</option></term>
262 <term><option>--ignore-inhibitors</option></term>
265 <para>When system shutdown or a sleep state is requested,
266 ignore inhibitor locks. Applications can establish inhibitor
267 locks to avoid that certain important operations (such as CD
268 burning or suchlike) are interrupted by system shutdown or a
269 sleep state. Any user may take these locks and privileged
270 users may override these locks. If any locks are taken,
271 shutdown and sleep state requests will normally fail
272 (regardless if privileged or not) and a list of active locks
273 is printed. However, if <option>--ignore-inhibitors</option>
274 is specified, the locks are ignored and not printed, and the
275 operation attempted anyway, possibly requiring additional
281 <term><option>-q</option></term>
282 <term><option>--quiet</option></term>
285 <para>Suppress output to standard output in
286 <command>snapshot</command>,
287 <command>is-active</command>,
288 <command>is-failed</command>,
289 <command>enable</command> and
290 <command>disable</command>.</para>
295 <term><option>--no-block</option></term>
298 <para>Do not synchronously wait for the requested operation
299 to finish. If this is not specified, the job will be
300 verified, enqueued and <command>systemctl</command> will
301 wait until it is completed. By passing this argument, it is
302 only verified and enqueued.</para>
307 <term><option>--no-legend</option></term>
310 <para>Do not print a legend, i.e. the column headers and
311 the footer with hints.</para>
316 <term><option>--no-pager</option></term>
319 <para>Do not pipe output into a pager.</para>
324 <term><option>--system</option></term>
327 <para>Talk to the systemd system manager. (Default)</para>
332 <term><option>--user</option></term>
335 <para>Talk to the systemd manager of the calling
341 <term><option>--no-wall</option></term>
344 <para>Do not send wall message before halt, power-off,
350 <term><option>--global</option></term>
353 <para>When used with <command>enable</command> and
354 <command>disable</command>, operate on the global user
355 configuration directory, thus enabling or disabling a unit
356 file globally for all future logins of all users.</para>
361 <term><option>--no-reload</option></term>
364 <para>When used with <command>enable</command> and
365 <command>disable</command>, do not implicitly reload daemon
366 configuration after executing the changes.</para>
371 <term><option>--no-ask-password</option></term>
374 <para>When used with <command>start</command> and related
375 commands, disables asking for passwords. Background services
376 may require input of a password or passphrase string, for
377 example to unlock system hard disks or cryptographic
378 certificates. Unless this option is specified and the
379 command is invoked from a terminal,
380 <command>systemctl</command> will query the user on the
381 terminal for the necessary secrets. Use this option to
382 switch this behavior off. In this case, the password must be
383 supplied by some other means (for example graphical password
384 agents) or the service might fail. This also disables
385 querying the user for authentication for privileged
392 <term><option>--kill-who=</option></term>
395 <para>When used with <command>kill</command>, choose which
396 processes to kill. Must be one of <option>main</option>,
397 <option>control</option> or <option>all</option> to select
398 whether to kill only the main process of the unit, the
399 control process or all processes of the unit. If omitted,
400 defaults to <option>all</option>.</para>
406 <term><option>-s</option></term>
407 <term><option>--signal=</option></term>
410 <para>When used with <command>kill</command>, choose which
411 signal to send to selected processes. Must be one of the
412 well known signal specifiers such as <constant>SIGTERM</constant>, <constant>SIGINT</constant> or
413 <constant>SIGSTOP</constant>. If omitted, defaults to
414 <option>SIGTERM</option>.</para>
419 <term><option>-f</option></term>
420 <term><option>--force</option></term>
423 <para>When used with <command>enable</command>, overwrite
424 any existing conflicting symlinks.</para>
426 <para>When used with <command>halt</command>,
427 <command>poweroff</command>, <command>reboot</command> or
428 <command>kexec</command>, execute the selected operation
429 without shutting down all units. However, all processes will
430 be killed forcibly and all file systems are unmounted or
431 remounted read-only. This is hence a drastic but relatively
432 safe option to request an immediate reboot. If
433 <option>--force</option> is specified twice for these
434 operations, they will be executed immediately without
435 terminating any processes or umounting any file
436 systems. Warning: specifying <option>--force</option> twice
437 with any of these operations might result in data
443 <term><option>--root=</option></term>
447 <command>enable</command>/<command>disable</command>/<command>is-enabled</command>
448 (and related commands), use alternative root path when
449 looking for unit files.</para>
455 <term><option>--runtime</option></term>
458 <para>When used with <command>enable</command>,
459 <command>disable</command>, <command>is-enabled</command>
460 (and related commands), make changes only temporarily, so
461 that they are lost on the next reboot. This will have the
462 effect that changes are not made in subdirectories of
463 <filename>/etc</filename> but in <filename>/run</filename>,
464 with identical immediate effects, however, since the latter
465 is lost on reboot, the changes are lost too.</para>
467 <para>Similar, when used with
468 <command>set-property</command>, make changes only
469 temporarily, so that they are lost on the next
475 <term><option>-H</option></term>
476 <term><option>--host</option></term>
479 <para>Execute the operation remotely. Specify a hostname, or
480 username and hostname separated by <literal>@</literal>, to
481 connect to. This will use SSH to talk to the remote systemd
487 <term><option>-M</option></term>
488 <term><option>--machine=</option></term>
490 <listitem><para>Execute the operation on a local
491 container. Specify a container name to connect
492 to.</para></listitem>
496 <term><option>-n</option></term>
497 <term><option>--lines=</option></term>
500 <para>When used with <command>status</command>, controls the
501 number of journal lines to show, counting from the most
502 recent ones. Takes a positive integer argument. Defaults to
508 <term><option>-o</option></term>
509 <term><option>--output=</option></term>
512 <para>When used with <command>status</command>, controls the
513 formatting of the journal entries that are shown. For the
514 available choices, see
515 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
516 Defaults to <literal>short</literal>.</para>
521 <term><option>--plain</option></term>
524 <para>When used with <command>list-dependencies</command>,
525 the output is printed as a list instead of a tree.</para>
533 <title>Commands</title>
535 <para>The following commands are understood:</para>
538 <title>Unit Commands</title>
542 <term><command>list-units</command></term>
545 <para>List known units (subject to limitations specified
546 with <option>-t</option>).</para>
548 <para>This is the default command.</para>
553 <term><command>list-sockets</command></term>
556 <para>List socket units ordered by the listening address. Produces output
559 LISTEN UNIT ACTIVATES
560 /dev/initctl systemd-initctl.socket systemd-initctl.service
562 [::]:22 sshd.socket sshd.service
563 kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
567 Note: because the addresses might contains spaces, this output
568 is not suitable for programmatic consumption.
571 <para>See also the options <option>--show-types</option>,
572 <option>--all</option>, and <option>--failed</option>.</para>
577 <term><command>list-timers</command></term>
580 <para>List timer units ordered by the time they elapse next.</para>
582 <para>See also the options <option>--all</option> and
583 <option>--failed</option>.</para>
588 <term><command>start <replaceable>NAME</replaceable>...</command></term>
591 <para>Start (activate) one or more units specified on the
596 <term><command>stop <replaceable>NAME</replaceable>...</command></term>
599 <para>Stop (deactivate) one or more units specified on the
604 <term><command>reload <replaceable>NAME</replaceable>...</command></term>
607 <para>Asks all units listed on the command line to reload
608 their configuration. Note that this will reload the
609 service-specific configuration, not the unit configuration
610 file of systemd. If you want systemd to reload the
611 configuration file of a unit, use the
612 <command>daemon-reload</command> command. In other words:
613 for the example case of Apache, this will reload Apache's
614 <filename>httpd.conf</filename> in the web server, not the
615 <filename>apache.service</filename> systemd unit
618 <para>This command should not be confused with the
619 <command>daemon-reload</command> or <command>load</command>
625 <term><command>restart <replaceable>NAME</replaceable>...</command></term>
628 <para>Restart one or more units specified on the command
629 line. If the units are not running yet, they will be
634 <term><command>try-restart <replaceable>NAME</replaceable>...</command></term>
637 <para>Restart one or more units specified on the command
638 line if the units are running. This does nothing if units are not
639 running. Note that, for compatibility with Red Hat init
640 scripts, <command>condrestart</command> is equivalent to this
645 <term><command>reload-or-restart <replaceable>NAME</replaceable>...</command></term>
648 <para>Reload one or more units if they support it. If not,
649 restart them instead. If the units are not running yet, they
650 will be started.</para>
654 <term><command>reload-or-try-restart <replaceable>NAME</replaceable>...</command></term>
657 <para>Reload one or more units if they support it. If not,
658 restart them instead. This does nothing if the units are not
659 running. Note that, for compatibility with SysV init scripts,
660 <command>force-reload</command> is equivalent to this
665 <term><command>isolate <replaceable>NAME</replaceable></command></term>
668 <para>Start the unit specified on the command line and its
669 dependencies and stop all others.</para>
671 <para>This is similar to changing the runlevel in a
672 traditional init system. The <command>isolate</command>
673 command will immediately stop processes that are not enabled
674 in the new unit, possibly including the graphical
675 environment or terminal you are currently using.</para>
677 <para>Note that this is allowed only on units where
678 <option>AllowIsolate=</option> is enabled. See
679 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
684 <term><command>kill <replaceable>NAME</replaceable>...</command></term>
687 <para>Send a signal to one or more processes of the
688 unit. Use <option>--kill-who=</option> to select which
689 process to kill. Use <option>--kill-mode=</option> to select
690 the kill mode and <option>--signal=</option> to select the
691 signal to send.</para>
695 <term><command>is-active <replaceable>NAME</replaceable>...</command></term>
698 <para>Check whether any of the specified units are active
699 (i.e. running). Returns an exit code 0 if at least one is
700 active, non-zero otherwise. Unless <option>--quiet</option>
701 is specified, this will also print the current unit state to
706 <term><command>is-failed <replaceable>NAME</replaceable>...</command></term>
709 <para>Check whether any of the specified units are in a "failed" state.
710 Returns an exit code 0 if at least one has failed, non-zero
711 otherwise. Unless <option>--quiet</option> is specified, this
712 will also print the current unit state to
717 <term><command>status [<replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...]</command></term>
720 <para>Show terse runtime status information about one or
721 more units, followed by most recent log data from the
722 journal. If no units are specified, show all units (subject
723 to limitations specified with <option>-t</option>). If a PID
724 is passed, show information about the unit the process
727 <para>This function is intended to generate human-readable
728 output. If you are looking for computer-parsable output, use
729 <command>show</command> instead.</para>
733 <term><command>show [<replaceable>NAME</replaceable>...|<replaceable>JOB</replaceable>...]</command></term>
736 <para>Show properties of one or more units, jobs, or the
737 manager itself. If no argument is specified, properties of
738 the manager will be shown. If a unit name is specified,
739 properties of the unit is shown, and if a job id is
740 specified, properties of the job is shown. By default, empty
741 properties are suppressed. Use <option>--all</option> to
742 show those too. To select specific properties to show, use
743 <option>--property=</option>. This command is intended to be
744 used whenever computer-parsable output is required. Use
745 <command>status</command> if you are looking for formatted
746 human-readable output.</para>
751 <term><command>set-property <replaceable>NAME</replaceable> <replaceable>ASSIGNMENT</replaceable>...</command></term>
754 <para>Set the specified unit properties at runtime where
755 this is supported. This allows changing configuration
756 parameter properties such as resource control settings at
757 runtime. Not all properties may be changed at runtime, but
758 many resource control settings (primarily those in
759 <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>)
760 may. The changes are applied instantly, and stored on disk
761 for future boots, unless <option>--runtime</option> is
762 passed, in which case the settings only apply until the
763 next reboot. The syntax of the property assignment follows
764 closely the syntax of assignments in unit files.</para>
766 <para>Example: <command>systemctl set-property foobar.service CPUShares=777</command></para>
768 <para>Note that this command allows changing multiple
769 properties at the same time, which is preferable over
770 setting them individually. Like unit file configuration
771 settings, assigning the empty list to list parameters will
772 reset the list.</para>
777 <term><command>help <replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...</command></term>
780 <para>Show manual pages for one or more units, if
781 available. If a PID is given, the manual pages for the unit
782 the process belongs to are shown.</para>
787 <term><command>reset-failed [<replaceable>NAME</replaceable>...]</command></term>
790 <para>Reset the <literal>failed</literal> state of the
791 specified units, or if no unit name is passed, reset the state of all
792 units. When a unit fails in some way (i.e. process exiting
793 with non-zero error code, terminating abnormally or timing
794 out), it will automatically enter the
795 <literal>failed</literal> state and its exit code and status
796 is recorded for introspection by the administrator until the
797 service is restarted or reset with this command.</para>
802 <term><command>list-dependencies <replaceable>NAME</replaceable></command></term>
805 <para>Shows required and wanted units of the specified
806 unit. If no unit is specified,
807 <filename>default.target</filename> is implied. Target units
808 are recursively expanded. When <option>--all</option> is
809 passed, all other units are recursively expanded as
817 <title>Unit File Commands</title>
821 <term><command>list-unit-files</command></term>
824 <para>List installed unit files.</para>
829 <term><command>enable <replaceable>NAME</replaceable>...</command></term>
832 <para>Enable one or more unit files or unit file instances,
833 as specified on the command line. This will create a number
834 of symlinks as encoded in the <literal>[Install]</literal>
835 sections of the unit files. After the symlinks have been
836 created, the systemd configuration is reloaded (in a way that
837 is equivalent to <command>daemon-reload</command>) to ensure
838 the changes are taken into account immediately. Note that
839 this does <emphasis>not</emphasis> have the effect of also
840 starting any of the units being enabled. If this
841 is desired, a separate <command>start</command> command must
842 be invoked for the unit. Also note that in case of instance
843 enablement, symlinks named the same as instances are created in
844 the install location, however they all point to the same
845 template unit file.</para>
847 <para>This command will print the actions executed. This
848 output may be suppressed by passing <option>--quiet</option>.
851 <para>Note that this operation creates only the suggested
852 symlinks for the units. While this command is the
853 recommended way to manipulate the unit configuration
854 directory, the administrator is free to make additional
855 changes manually by placing or removing symlinks in the
856 directory. This is particularly useful to create
857 configurations that deviate from the suggested default
858 installation. In this case, the administrator must make sure
859 to invoke <command>daemon-reload</command> manually as
860 necessary to ensure the changes are taken into account.
863 <para>Enabling units should not be confused with starting
864 (activating) units, as done by the <command>start</command>
865 command. Enabling and starting units is orthogonal: units
866 may be enabled without being started and started without
867 being enabled. Enabling simply hooks the unit into various
868 suggested places (for example, so that the unit is
869 automatically started on boot or when a particular kind of
870 hardware is plugged in). Starting actually spawns the daemon
871 process (in case of service units), or binds the socket (in
872 case of socket units), and so on.</para>
874 <para>Depending on whether <option>--system</option>,
875 <option>--user</option>, <option>--runtime</option>,
876 or <option>--global</option> is specified, this enables the unit
877 for the system, for the calling user only, for only this boot of
878 the system, or for all future logins of all users, or only this
879 boot. Note that in the last case, no systemd daemon
880 configuration is reloaded.</para>
885 <term><command>disable <replaceable>NAME</replaceable>...</command></term>
888 <para>Disables one or more units. This removes all symlinks
889 to the specified unit files from the unit configuration
890 directory, and hence undoes the changes made by
891 <command>enable</command>. Note however that this removes
892 all symlinks to the unit files (i.e. including manual
893 additions), not just those actually created by
894 <command>enable</command>. This call implicitly reloads the
895 systemd daemon configuration after completing the disabling
896 of the units. Note that this command does not implicitly
897 stop the units that are being disabled. If this is desired,
898 an additional <command>stop</command> command should be
899 executed afterwards.</para>
901 <para>This command will print the actions executed. This
902 output may be suppressed by passing <option>--quiet</option>.
905 <para>This command honors <option>--system</option>,
906 <option>--user</option>, <option>--runtime</option> and
907 <option>--global</option> in a similar way as
908 <command>enable</command>.</para>
913 <term><command>is-enabled <replaceable>NAME</replaceable>...</command></term>
916 <para>Checks whether any of the specified unit files are
917 enabled (as with <command>enable</command>). Returns an exit
918 code of 0 if at least one is enabled, non-zero
919 otherwise. Prints the current enable status. To suppress
920 this output, use <option>--quiet</option>.</para>
925 <term><command>reenable <replaceable>NAME</replaceable>...</command></term>
928 <para>Reenable one or more unit files, as specified on the
929 command line. This is a combination of
930 <command>disable</command> and <command>enable</command> and
931 is useful to reset the symlinks a unit is enabled with to
932 the defaults configured in the <literal>[Install]</literal>
933 section of the unit file.</para>
938 <term><command>preset <replaceable>NAME</replaceable>...</command></term>
941 <para>Reset one or more unit files, as specified on the
942 command line, to the defaults configured in the preset
943 policy files. This has the same effect as
944 <command>disable</command> or <command>enable</command>,
945 depending how the unit is listed in the preset files. For
946 more information on the preset policy format, see
947 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
948 For more information on the concept of presets, please
950 <ulink url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>
956 <term><command>mask <replaceable>NAME</replaceable>...</command></term>
959 <para>Mask one or more unit files, as specified on the
960 command line. This will link these units to
961 <filename>/dev/null</filename>, making it impossible to
962 start them. This is a stronger version of
963 <command>disable</command>, since it prohibits all kinds of
964 activation of the unit, including manual activation. Use
965 this option with care. This honors the
966 <option>--runtime</option> option to only mask temporarily
967 until the next reoobt of the system.</para>
972 <term><command>unmask <replaceable>NAME</replaceable>...</command></term>
975 <para>Unmask one or more unit files, as specified on the
976 command line. This will undo the effect of
977 <command>mask</command>.</para>
982 <term><command>link <replaceable>FILENAME</replaceable>...</command></term>
985 <para>Link a unit file that is not in the unit file search
986 paths into the unit file search path. This requires an
987 absolute path to a unit file. The effect of this can be
988 undone with <command>disable</command>. The effect of this
989 command is that a unit file is available for
990 <command>start</command> and other commands although it
991 is not installed directly in the unit search path.</para>
996 <term><command>get-default</command></term>
999 <para>Get the default target specified
1000 via <filename>default.target</filename> link.</para>
1005 <term><command>set-default <replaceable>NAME</replaceable></command></term>
1008 <para>Set the default target to boot into. Command links
1009 <filename>default.target</filename> to the given unit.</para>
1016 <title>Job Commands</title>
1020 <term><command>list-jobs</command></term>
1023 <para>List jobs that are in progress.</para>
1027 <term><command>cancel <replaceable>JOB</replaceable>...</command></term>
1030 <para>Cancel one or more jobs specified on the command line
1031 by their numeric job IDs. If no job ID is specified, cancel
1032 all pending jobs.</para>
1039 <title>Snapshot Commands</title>
1043 <term><command>snapshot [<replaceable>NAME</replaceable>]</command></term>
1046 <para>Create a snapshot. If a snapshot name is specified,
1047 the new snapshot will be named after it. If none is
1048 specified, an automatic snapshot name is generated. In either
1049 case, the snapshot name used is printed to STDOUT, unless
1050 <option>--quiet</option> is specified.</para>
1052 <para>A snapshot refers to a saved state of the systemd
1053 manager. It is implemented itself as a unit that is
1054 generated dynamically with this command and has dependencies
1055 on all units active at the time. At a later time, the user
1056 may return to this state by using the
1057 <command>isolate</command> command on the snapshot unit.
1060 <para>Snapshots are only useful for saving and restoring
1061 which units are running or are stopped, they do not
1062 save/restore any other state. Snapshots are dynamic and lost
1067 <term><command>delete <replaceable>NAME</replaceable>...</command></term>
1070 <para>Remove a snapshot previously created with
1071 <command>snapshot</command>.</para>
1078 <title>Environment Commands</title>
1082 <term><command>show-environment</command></term>
1085 <para>Dump the systemd manager environment block. The
1086 environment block will be dumped in straight-forward form
1087 suitable for sourcing into a shell script. This environment
1088 block will be passed to all processes the manager
1093 <term><command>set-environment <replaceable>VARIABLE=VALUE</replaceable>...</command></term>
1096 <para>Set one or more systemd manager environment variables,
1097 as specified on the command line.</para>
1101 <term><command>unset-environment <replaceable>VARIABLE</replaceable>...</command></term>
1104 <para>Unset one or more systemd manager environment
1105 variables. If only a variable name is specified, it will be
1106 removed regardless of its value. If a variable and a value
1107 are specified, the variable is only removed if it has the
1108 specified value.</para>
1115 <title>Manager Lifecycle Commands</title>
1119 <term><command>daemon-reload</command></term>
1122 <para>Reload systemd manager configuration. This will reload
1123 all unit files and recreate the entire dependency
1124 tree. While the daemon is being reloaded, all sockets systemd
1125 listens on on behalf of user configuration will stay
1126 accessible.</para> <para>This command should not be confused
1127 with the <command>load</command> or
1128 <command>reload</command> commands.</para>
1132 <term><command>daemon-reexec</command></term>
1135 <para>Reexecute the systemd manager. This will serialize the
1136 manager state, reexecute the process and deserialize the
1137 state again. This command is of little use except for
1138 debugging and package upgrades. Sometimes, it might be
1139 helpful as a heavy-weight <command>daemon-reload</command>.
1140 While the daemon is being reexecuted, all sockets systemd listening
1141 on behalf of user configuration will stay accessible.
1149 <title>System Commands</title>
1153 <term><command>default</command></term>
1156 <para>Enter default mode. This is mostly equivalent to
1157 <command>isolate default.target</command>.</para>
1161 <term><command>rescue</command></term>
1164 <para>Enter rescue mode. This is mostly equivalent to
1165 <command>isolate rescue.target</command>, but also prints a
1166 wall message to all users.</para>
1170 <term><command>emergency</command></term>
1173 <para>Enter emergency mode. This is mostly equivalent to
1174 <command>isolate emergency.target</command>, but also prints
1175 a wall message to all users.</para>
1179 <term><command>halt</command></term>
1182 <para>Shut down and halt the system. This is mostly equivalent to
1183 <command>start halt.target --irreversible</command>, but also
1184 prints a wall message to all users. If combined with
1185 <option>--force</option>, shutdown of all running services is
1186 skipped, however all processes are killed and all file
1187 systems are unmounted or mounted read-only, immediately
1188 followed by the system halt. If <option>--force</option> is
1189 specified twice, the operation is immediately executed
1190 without terminating any processes or unmounting any file
1191 systems. This may result in data loss.</para>
1195 <term><command>poweroff</command></term>
1198 <para>Shut down and power-off the system. This is mostly
1199 equivalent to <command>start poweroff.target --irreversible</command>,
1200 but also prints a wall message to all users. If combined with
1201 <option>--force</option>, shutdown of all running services is
1202 skipped, however all processes are killed and all file
1203 systems are unmounted or mounted read-only, immediately
1204 followed by the powering off. If <option>--force</option> is
1205 specified twice, the operation is immediately executed
1206 without terminating any processes or unmounting any file
1207 systems. This may result in data loss.</para>
1211 <term><command>reboot <optional><replaceable>arg</replaceable></optional></command></term>
1214 <para>Shut down and reboot the system. This is mostly
1215 equivalent to <command>start reboot.target --irreversible</command>,
1216 but also prints a wall message to all users. If combined with
1217 <option>--force</option>, shutdown of all running services is
1218 skipped, however all processes are killed and all file
1219 systems are unmounted or mounted read-only, immediately
1220 followed by the reboot. If <option>--force</option> is
1221 specified twice, the operation is immediately executed
1222 without terminating any processes or unmounting any file
1223 systems. This may result in data loss.</para>
1225 <para>If the optional argument
1226 <replaceable>arg</replaceable> is given, it will be passed
1227 as the optional argument to the
1228 <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
1229 system call. The value is architecture and firmware
1230 specific. As an example, <literal>recovery</literal> might
1231 be used to trigger system recovery, and
1232 <literal>fota</literal> might be used to trigger a
1233 <quote>firmware over the air</quote> update.</para>
1237 <term><command>kexec</command></term>
1240 <para>Shut down and reboot the system via kexec. This is
1241 mostly equivalent to <command>start kexec.target --irreversible</command>,
1242 but also prints a wall message to all users. If combined
1243 with <option>--force</option>, shutdown of all running
1244 services is skipped, however all processes are killed and
1245 all file systems are unmounted or mounted read-only,
1246 immediately followed by the reboot.</para>
1250 <term><command>exit</command></term>
1253 <para>Ask the systemd manager to quit. This is only
1254 supported for user service managers (i.e. in conjunction
1255 with the <option>--user</option> option) and will fail
1261 <term><command>suspend</command></term>
1264 <para>Suspend the system. This will trigger activation of
1265 the special <filename>suspend.target</filename> target.
1270 <term><command>hibernate</command></term>
1273 <para>Hibernate the system. This will trigger activation of
1274 the special <filename>hibernate.target</filename> target.
1279 <term><command>hybrid-sleep</command></term>
1282 <para>Hibernate and suspend the system. This will trigger
1283 activation of the special
1284 <filename>hybrid-sleep.target</filename> target.</para>
1288 <term><command>switch-root <replaceable>ROOT</replaceable> [<replaceable>INIT</replaceable>]</command></term>
1291 <para>Switches to a different root directory and executes a
1292 new system manager process below it. This is intended for
1293 usage in initial RAM disks ("initrd"), and will transition
1294 from the initrd's system manager process (a.k.a "init"
1295 process) to the main system manager process. This call takes two
1296 arguments: the directory that is to become the new root directory, and
1297 the path to the new system manager binary below it to
1298 execute as PID 1. If the latter is omitted or the empty
1299 string, a systemd binary will automatically be searched for
1300 and used as init. If the system manager path is omitted or
1301 equal to the empty string, the state of the initrd's system
1302 manager process is passed to the main system manager, which
1303 allows later introspection of the state of the services
1304 involved in the initrd boot.</para>
1313 <title>Exit status</title>
1315 <para>On success, 0 is returned, a non-zero failure
1316 code otherwise.</para>
1320 <title>Environment</title>
1322 <variablelist class='environment-variables'>
1324 <term><varname>$SYSTEMD_PAGER</varname></term>
1327 <para>Pager to use when <option>--no-pager</option> is not
1328 given; overrides <varname>$PAGER</varname>. Setting this to
1329 an empty string or the value <literal>cat</literal> is
1330 equivalent to passing
1331 <option>--no-pager</option>.</para>
1338 <title>See Also</title>
1340 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1341 <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1342 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1343 <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1344 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1345 <citerefentry><refentrytitle>systemd.resource-management</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1346 <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1347 <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1348 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>