man/systemctl.xml

   1 <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
   4 <!ENTITY % entities SYSTEM "custom-entities.ent" >
   5 %entities;
   6 ]>
   7
   8 <!--
   9   This file is part of systemd.
  10
  11   Copyright 2010 Lennart Poettering
  12
  13   systemd is free software; you can redistribute it and/or modify it
  14   under the terms of the GNU Lesser General Public License as published by
  15   the Free Software Foundation; either version 2.1 of the License, or
  16   (at your option) any later version.
  17
  18   systemd is distributed in the hope that it will be useful, but
  19   WITHOUT ANY WARRANTY; without even the implied warranty of
  20   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  21   Lesser General Public License for more details.
  22
  23   You should have received a copy of the GNU Lesser General Public License
  24   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  25 -->
  26
  27 <refentry id="systemctl"
  28           xmlns:xi="http://www.w3.org/2001/XInclude">
  29
  30   <refentryinfo>
  31     <title>systemctl</title>
  32     <productname>systemd</productname>
  33
  34     <authorgroup>
  35       <author>
  36         <contrib>Developer</contrib>
  37         <firstname>Lennart</firstname>
  38         <surname>Poettering</surname>
  39         <email>lennart@poettering.net</email>
  40       </author>
  41     </authorgroup>
  42   </refentryinfo>
  43
  44   <refmeta>
  45     <refentrytitle>systemctl</refentrytitle>
  46     <manvolnum>1</manvolnum>
  47   </refmeta>
  48
  49   <refnamediv>
  50     <refname>systemctl</refname>
  51     <refpurpose>Control the systemd system and service manager</refpurpose>
  52   </refnamediv>
  53
  54   <refsynopsisdiv>
  55     <cmdsynopsis>
  56       <command>systemctl</command>
  57       <arg choice="opt" rep="repeat">OPTIONS</arg>
  58       <arg choice="plain">COMMAND</arg>
  59       <arg choice="opt" rep="repeat">NAME</arg>
  60     </cmdsynopsis>
  61   </refsynopsisdiv>
  62
  63   <refsect1>
  64     <title>Description</title>
  65
  66     <para><command>systemctl</command> may be used to introspect and
  67     control the state of the <literal>systemd</literal> system and
  68     service manager. Please refer to
  69     <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  70     for an introduction into the basic concepts and functionality this
  71     tool manages.</para>
  72   </refsect1>
  73
  74   <refsect1>
  75     <title>Options</title>
  76
  77     <para>The following options are understood:</para>
  78
  79     <variablelist>
  80       <varlistentry>
  81         <term><option>-t</option></term>
  82         <term><option>--type=</option></term>
  83
  84         <listitem>
  85           <para>The argument should be a comma-separated list of unit
  86           types such as <option>service</option> and
  87           <option>socket</option>.
  88           </para>
  89
  90           <para>If one of the arguments is a unit type, when listing
  91           units, limit display to certain unit types. Otherwise, units
  92           of all types will be shown.</para>
  93
  94           <para>As a special case, if one of the arguments is
  95           <option>help</option>, a list of allowed values will be
  96           printed and the program will exit.</para>
  97         </listitem>
  98       </varlistentry>
  99
 100       <varlistentry>
 101         <term><option>--state=</option></term>
 102
 103         <listitem>
 104         <para>The argument should be a comma-separated list of unit
 105         LOAD, SUB, or ACTIVE states. When listing units, show only
 106         those in specified states. Use <option>--state=failed</option>
 107         to show only failed units.</para>
 108         </listitem>
 109       </varlistentry>
 110
 111       <varlistentry>
 112         <term><option>-p</option></term>
 113         <term><option>--property=</option></term>
 114
 115         <listitem>
 116           <para>When showing unit/job/manager properties with the
 117           <command>show</command> command, limit display to properties
 118           specified in the argument. The argument should be a
 119           comma-separated list of property names, such as
 120           <literal>MainPID</literal>. Unless specified, all known
 121           properties are shown. If specified more than once, all
 122           properties with the specified names are shown. Shell
 123           completion is implemented for property names.</para>
 124
 125           <para>For the manager itself,
 126           <command>systemctl show</command> will show all available
 127           properties. Those properties are documented in
 128           <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 129           </para>
 130
 131           <para>Properties for units vary by unit type, so showing any
 132           unit (even a non-existent one) is a way to list properties
 133           pertaining to this type. Similarly showing any job will list
 134           properties pertaining to all jobs. Properties for units are
 135           documented in
 136           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 137           and the pages for individual unit types
 138           <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 139           <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 140           etc.</para>
 141         </listitem>
 142       </varlistentry>
 143
 144       <varlistentry>
 145         <term><option>-a</option></term>
 146         <term><option>--all</option></term>
 147
 148         <listitem>
 149           <para>When listing units, show all loaded units, regardless
 150           of their state, including inactive units. When showing
 151           unit/job/manager properties, show all properties regardless
 152           whether they are set or not.</para>
 153           <para>To list all units installed on the system, use the
 154           <command>list-unit-files</command> command instead.</para>
 155         </listitem>
 156       </varlistentry>
 157
 158       <varlistentry>
 159         <term><option>-r</option></term>
 160         <term><option>--recursive</option></term>
 161
 162         <listitem>
 163           <para>When listing units, also show units of local
 164           containers. Units of local containers will be prefixed with
 165           the container name, separated by a single colon character
 166           (<literal>:</literal>).</para>
 167         </listitem>
 168       </varlistentry>
 169
 170       <varlistentry>
 171         <term><option>--reverse</option></term>
 172
 173         <listitem>
 174           <para>Show reverse dependencies between units with
 175           <command>list-dependencies</command>, i.e. follow
 176           dependencies of type <varname>WantedBy=</varname>,
 177           <varname>RequiredBy=</varname>,
 178           <varname>RequiredByOverridable=</varname>,
 179           <varname>PartOf=</varname>, <varname>BoundBy=</varname>,
 180           instead of <varname>Wants=</varname> and similar.
 181           </para>
 182         </listitem>
 183       </varlistentry>
 184
 185       <varlistentry>
 186         <term><option>--after</option></term>
 187
 188         <listitem>
 189           <para>With <command>list-dependencies</command>, show the
 190           units that are ordered before the specified unit. In other
 191           words, recursively list units following the
 192           <varname>After=</varname> dependency.</para>
 193
 194           <para>Note that any <varname>After=</varname> dependency is
 195           automatically mirrored to create a
 196           <varname>Before=</varname> dependency. Temporal dependencies
 197           may be specified explicitly, but are also created implicitly
 198           for units which are <varname>WantedBy=</varname> targets
 199           (see
 200           <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>),
 201           and as a result of other directives (for example
 202           <varname>RequiresMountsFor=</varname>). Both explicitly
 203           and implicitly introduced dependencies are shown with
 204           <command>list-dependencies</command>.</para>
 205         </listitem>
 206       </varlistentry>
 207
 208       <varlistentry>
 209         <term><option>--before</option></term>
 210
 211         <listitem>
 212           <para>With <command>list-dependencies</command>, show the
 213           units that are ordered after the specified unit. In other
 214           words, recursively list units following the
 215           <varname>Before=</varname> dependency.</para>
 216         </listitem>
 217       </varlistentry>
 218
 219       <varlistentry>
 220         <term><option>-l</option></term>
 221         <term><option>--full</option></term>
 222
 223         <listitem>
 224           <para>Do not ellipsize unit names, process tree entries,
 225           journal output, or truncate unit descriptions in the output
 226           of <command>status</command>, <command>list-units</command>,
 227           <command>list-jobs</command>, and
 228           <command>list-timers</command>.</para>
 229         </listitem>
 230       </varlistentry>
 231
 232       <varlistentry>
 233         <term><option>--show-types</option></term>
 234
 235         <listitem>
 236           <para>When showing sockets, show the type of the socket.</para>
 237         </listitem>
 238       </varlistentry>
 239
 240       <varlistentry>
 241         <term><option>--job-mode=</option></term>
 242
 243         <listitem>
 244         <para>When queuing a new job, this option controls how to deal with
 245         already queued jobs. It takes one of <literal>fail</literal>,
 246         <literal>replace</literal>,
 247         <literal>replace-irreversibly</literal>,
 248         <literal>isolate</literal>,
 249         <literal>ignore-dependencies</literal>,
 250         <literal>ignore-requirements</literal> or
 251         <literal>flush</literal>. Defaults to
 252         <literal>replace</literal>, except when the
 253         <command>isolate</command> command is used which implies the
 254         <literal>isolate</literal> job mode.</para>
 255
 256         <para>If <literal>fail</literal> is specified and a requested
 257         operation conflicts with a pending job (more specifically:
 258         causes an already pending start job to be reversed into a stop
 259         job or vice versa), cause the operation to fail.</para>
 260
 261         <para>If <literal>replace</literal> (the default) is
 262         specified, any conflicting pending job will be replaced, as
 263         necessary.</para>
 264
 265         <para>If <literal>replace-irreversibly</literal> is specified,
 266         operate like <literal>replace</literal>, but also mark the new
 267         jobs as irreversible. This prevents future conflicting
 268         transactions from replacing these jobs (or even being enqueued
 269         while the irreversible jobs are still pending). Irreversible
 270         jobs can still be cancelled using the <command>cancel</command>
 271         command.</para>
 272
 273         <para><literal>isolate</literal> is only valid for start
 274         operations and causes all other units to be stopped when the
 275         specified unit is started. This mode is always used when the
 276         <command>isolate</command> command is used.</para>
 277
 278         <para><literal>flush</literal> will cause all queued jobs to
 279         be canceled when the new job is enqueued.</para>
 280
 281         <para>If <literal>ignore-dependencies</literal> is specified,
 282         then all unit dependencies are ignored for this new job and
 283         the operation is executed immediately. If passed, no required
 284         units of the unit passed will be pulled in, and no ordering
 285         dependencies will be honored. This is mostly a debugging and
 286         rescue tool for the administrator and should not be used by
 287         applications.</para>
 288
 289         <para><literal>ignore-requirements</literal> is similar to
 290         <literal>ignore-dependencies</literal>, but only causes the
 291         requirement dependencies to be ignored, the ordering
 292         dependencies will still be honoured.</para>
 293         </listitem>
 294
 295       </varlistentry>
 296
 297       <varlistentry>
 298         <term><option>-i</option></term>
 299         <term><option>--ignore-inhibitors</option></term>
 300
 301         <listitem>
 302           <para>When system shutdown or a sleep state is requested,
 303           ignore inhibitor locks. Applications can establish inhibitor
 304           locks to avoid that certain important operations (such as CD
 305           burning or suchlike) are interrupted by system shutdown or a
 306           sleep state. Any user may take these locks and privileged
 307           users may override these locks. If any locks are taken,
 308           shutdown and sleep state requests will normally fail
 309           (regardless of whether privileged or not) and a list of active locks
 310           is printed. However, if <option>--ignore-inhibitors</option>
 311           is specified, the locks are ignored and not printed, and the
 312           operation attempted anyway, possibly requiring additional
 313           privileges.</para>
 314         </listitem>
 315       </varlistentry>
 316
 317       <varlistentry>
 318         <term><option>-q</option></term>
 319         <term><option>--quiet</option></term>
 320
 321         <listitem>
 322           <para>Suppress printing of the results of various commands
 323           and also the hints about truncated log lines. This does not
 324           suppress output of commands for which the printed output is
 325           the only result (like <command>show</command>). Errors are
 326           always printed.</para>
 327         </listitem>
 328       </varlistentry>
 329
 330       <varlistentry>
 331         <term><option>--no-block</option></term>
 332
 333         <listitem>
 334           <para>Do not synchronously wait for the requested operation
 335           to finish. If this is not specified, the job will be
 336           verified, enqueued and <command>systemctl</command> will
 337           wait until the unit's start-up is completed. By passing this
 338           argument, it is only verified and enqueued.</para>
 339         </listitem>
 340       </varlistentry>
 341
 342       <xi:include href="user-system-options.xml" xpointer="user" />
 343       <xi:include href="user-system-options.xml" xpointer="system" />
 344
 345       <!-- we do not document -failed here, as it has been made
 346            redundant by -state=failed, which it predates. To keep
 347            things simple we only document the new switch, while
 348            keeping the old one around for compatibility only. -->
 349
 350       <varlistentry>
 351         <term><option>--no-wall</option></term>
 352
 353         <listitem>
 354           <para>Do not send wall message before halt, power-off,
 355           reboot.</para>
 356         </listitem>
 357       </varlistentry>
 358
 359       <varlistentry>
 360         <term><option>--global</option></term>
 361
 362         <listitem>
 363           <para>When used with <command>enable</command> and
 364           <command>disable</command>, operate on the global user
 365           configuration directory, thus enabling or disabling a unit
 366           file globally for all future logins of all users.</para>
 367         </listitem>
 368       </varlistentry>
 369
 370       <varlistentry>
 371         <term><option>--no-reload</option></term>
 372
 373         <listitem>
 374           <para>When used with <command>enable</command> and
 375           <command>disable</command>, do not implicitly reload daemon
 376           configuration after executing the changes.</para>
 377         </listitem>
 378       </varlistentry>
 379
 380       <varlistentry>
 381         <term><option>--no-ask-password</option></term>
 382
 383         <listitem>
 384           <para>When used with <command>start</command> and related
 385           commands, disables asking for passwords. Background services
 386           may require input of a password or passphrase string, for
 387           example to unlock system hard disks or cryptographic
 388           certificates. Unless this option is specified and the
 389           command is invoked from a terminal,
 390           <command>systemctl</command> will query the user on the
 391           terminal for the necessary secrets. Use this option to
 392           switch this behavior off. In this case, the password must be
 393           supplied by some other means (for example graphical password
 394           agents) or the service might fail. This also disables
 395           querying the user for authentication for privileged
 396           operations.</para>
 397         </listitem>
 398       </varlistentry>
 399
 400       <varlistentry>
 401         <term><option>--kill-who=</option></term>
 402
 403         <listitem>
 404           <para>When used with <command>kill</command>, choose which
 405           processes to send a signal to. Must be one of
 406           <option>main</option>, <option>control</option> or
 407           <option>all</option> to select whether to kill only the main
 408           process, the control process or all processes of the
 409           unit. The main process of the unit is the one that defines
 410           the life-time of it. A control process of a unit is one that
 411           is invoked by the manager to induce state changes of it. For
 412           example, all processes started due to the
 413           <varname>ExecStartPre=</varname>,
 414           <varname>ExecStop=</varname> or
 415           <varname>ExecReload=</varname> settings of service units are
 416           control processes. Note that there is only one control
 417           process per unit at a time, as only one state change is
 418           executed at a time. For services of type
 419           <varname>Type=forking</varname>, the initial process started
 420           by the manager for <varname>ExecStart=</varname> is a
 421           control process, while the process ultimately forked off by
 422           that one is then considered the main process of the unit (if
 423           it can be determined). This is different for service units
 424           of other types, where the process forked off by the manager
 425           for <varname>ExecStart=</varname> is always the main process
 426           itself. A service unit consists of zero or one main process,
 427           zero or one control process plus any number of additional
 428           processes. Not all unit types manage processes of these
 429           types however. For example, for mount units, control processes
 430           are defined (which are the invocations of
 431           <filename>&MOUNT_PATH;</filename> and
 432           <filename>&UMOUNT_PATH;</filename>), but no main process
 433           is defined. If omitted, defaults to
 434           <option>all</option>.</para>
 435         </listitem>
 436
 437       </varlistentry>
 438
 439       <varlistentry>
 440         <term><option>-s</option></term>
 441         <term><option>--signal=</option></term>
 442
 443         <listitem>
 444           <para>When used with <command>kill</command>, choose which
 445           signal to send to selected processes. Must be one of the
 446           well known signal specifiers such as <constant>SIGTERM</constant>, <constant>SIGINT</constant> or
 447           <constant>SIGSTOP</constant>. If omitted, defaults to
 448           <option>SIGTERM</option>.</para>
 449         </listitem>
 450       </varlistentry>
 451
 452       <varlistentry>
 453         <term><option>-f</option></term>
 454         <term><option>--force</option></term>
 455
 456         <listitem>
 457           <para>When used with <command>enable</command>, overwrite
 458           any existing conflicting symlinks.</para>
 459
 460           <para>When used with <command>halt</command>,
 461           <command>poweroff</command>, <command>reboot</command> or
 462           <command>kexec</command>, execute the selected operation
 463           without shutting down all units. However, all processes will
 464           be killed forcibly and all file systems are unmounted or
 465           remounted read-only. This is hence a drastic but relatively
 466           safe option to request an immediate reboot. If
 467           <option>--force</option> is specified twice for these
 468           operations, they will be executed immediately without
 469           terminating any processes or unmounting any file
 470           systems. Warning: specifying <option>--force</option> twice
 471           with any of these operations might result in data
 472           loss.</para>
 473         </listitem>
 474       </varlistentry>
 475
 476       <varlistentry>
 477         <term><option>--now</option></term>
 478
 479         <listitem>
 480           <para>When used with <command>enable</command>, the units
 481           will also be started. When used with <command>disable</command> or
 482           <command>mask</command>, the units will also be stopped. The start
 483           or stop operation is only carried out when the respective enable or
 484           disable operation has been successful.</para>
 485         </listitem>
 486       </varlistentry>
 487
 488       <varlistentry>
 489         <term><option>--root=</option></term>
 490
 491         <listitem>
 492           <para>When used with
 493           <command>enable</command>/<command>disable</command>/<command>is-enabled</command>
 494           (and related commands), use alternative root path when
 495           looking for unit files.</para>
 496         </listitem>
 497
 498       </varlistentry>
 499
 500       <varlistentry>
 501         <term><option>--runtime</option></term>
 502
 503         <listitem>
 504           <para>When used with <command>enable</command>,
 505           <command>disable</command>, <command>edit</command>,
 506           (and related commands), make changes only temporarily, so
 507           that they are lost on the next reboot. This will have the
 508           effect that changes are not made in subdirectories of
 509           <filename>/etc</filename> but in <filename>/run</filename>,
 510           with identical immediate effects, however, since the latter
 511           is lost on reboot, the changes are lost too.</para>
 512
 513           <para>Similarly, when used with
 514           <command>set-property</command>, make changes only
 515           temporarily, so that they are lost on the next
 516           reboot.</para>
 517         </listitem>
 518       </varlistentry>
 519
 520       <varlistentry>
 521         <term><option>--preset-mode=</option></term>
 522
 523         <listitem>
 524           <para>Takes one of <literal>full</literal> (the default),
 525           <literal>enable-only</literal>,
 526           <literal>disable-only</literal>. When used with the
 527           <command>preset</command> or <command>preset-all</command>
 528           commands, controls whether units shall be disabled and
 529           enabled according to the preset rules, or only enabled, or
 530           only disabled.</para>
 531         </listitem>
 532       </varlistentry>
 533
 534       <varlistentry>
 535         <term><option>-n</option></term>
 536         <term><option>--lines=</option></term>
 537
 538         <listitem>
 539           <para>When used with <command>status</command>, controls the
 540           number of journal lines to show, counting from the most
 541           recent ones. Takes a positive integer argument. Defaults to
 542           10.</para>
 543         </listitem>
 544       </varlistentry>
 545
 546       <varlistentry>
 547         <term><option>-o</option></term>
 548         <term><option>--output=</option></term>
 549
 550         <listitem>
 551           <para>When used with <command>status</command>, controls the
 552           formatting of the journal entries that are shown. For the
 553           available choices, see
 554           <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
 555           Defaults to <literal>short</literal>.</para>
 556         </listitem>
 557       </varlistentry>
 558
 559       <varlistentry>
 560         <term><option>--firmware-setup</option></term>
 561
 562         <listitem>
 563           <para>When used with the <command>reboot</command> command,
 564           indicate to the system's firmware to boot into setup
 565           mode. Note that this is currently only supported on some EFI
 566           systems and only if the system was booted in EFI
 567           mode.</para>
 568         </listitem>
 569       </varlistentry>
 570
 571       <varlistentry>
 572         <term><option>--plain</option></term>
 573
 574         <listitem>
 575           <para>When used with <command>list-dependencies</command>,
 576           the output is printed as a list instead of a tree.</para>
 577         </listitem>
 578       </varlistentry>
 579
 580       <xi:include href="user-system-options.xml" xpointer="host" />
 581       <xi:include href="user-system-options.xml" xpointer="machine" />
 582
 583       <xi:include href="standard-options.xml" xpointer="no-pager" />
 584       <xi:include href="standard-options.xml" xpointer="no-legend" />
 585       <xi:include href="standard-options.xml" xpointer="help" />
 586       <xi:include href="standard-options.xml" xpointer="version" />
 587     </variablelist>
 588   </refsect1>
 589
 590   <refsect1>
 591     <title>Commands</title>
 592
 593     <para>The following commands are understood:</para>
 594
 595     <refsect2>
 596       <title>Unit Commands</title>
 597
 598       <variablelist>
 599         <varlistentry>
 600           <term><command>list-units <optional><replaceable>PATTERN</replaceable>...</optional></command></term>
 601
 602           <listitem>
 603             <para>List known units (subject to limitations specified
 604             with <option>-t</option>). If one or more
 605             <replaceable>PATTERN</replaceable>s are specified, only
 606             units matching one of them are shown.</para>
 607
 608             <para>This is the default command.</para>
 609           </listitem>
 610         </varlistentry>
 611
 612         <varlistentry>
 613           <term><command>list-sockets <optional><replaceable>PATTERN</replaceable>...</optional></command></term>
 614
 615           <listitem>
 616             <para>List socket units ordered by listening address.
 617             If one or more <replaceable>PATTERN</replaceable>s are
 618             specified, only socket units matching one of them are
 619             shown. Produces output similar to
 620             <programlisting>
 621 LISTEN           UNIT                        ACTIVATES
 622 /dev/initctl     systemd-initctl.socket      systemd-initctl.service
 623 ...
 624 [::]:22          sshd.socket                 sshd.service
 625 kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
 626
 627 5 sockets listed.</programlisting>
 628             Note: because the addresses might contains spaces, this output
 629             is not suitable for programmatic consumption.
 630             </para>
 631
 632             <para>See also the options <option>--show-types</option>,
 633             <option>--all</option>, and <option>--state=</option>.</para>
 634           </listitem>
 635         </varlistentry>
 636
 637         <varlistentry>
 638           <term><command>list-timers <optional><replaceable>PATTERN</replaceable>...</optional></command></term>
 639
 640           <listitem>
 641             <para>List timer units ordered by the time they elapse
 642             next. If one or more <replaceable>PATTERN</replaceable>s
 643             are specified, only units matching one of them are shown.
 644             </para>
 645
 646             <para>See also the options <option>--all</option> and
 647             <option>--state=</option>.</para>
 648           </listitem>
 649         </varlistentry>
 650
 651         <varlistentry>
 652           <term><command>start <replaceable>PATTERN</replaceable>...</command></term>
 653
 654           <listitem>
 655             <para>Start (activate) one or more units specified on the
 656             command line.</para>
 657
 658             <para>Note that glob patterns operate on a list of currently
 659             loaded units. Units which are not active and are not in a
 660             failed state usually are not loaded, and would not be
 661             matched by any pattern. In addition, in case of
 662             instantiated units, systemd is often unaware of the
 663             instance name until the instance has been started. Therefore,
 664             using glob patterns with <command>start</command>
 665             has limited usefulness.</para>
 666           </listitem>
 667         </varlistentry>
 668         <varlistentry>
 669           <term><command>stop <replaceable>PATTERN</replaceable>...</command></term>
 670
 671           <listitem>
 672             <para>Stop (deactivate) one or more units specified on the
 673             command line.</para>
 674           </listitem>
 675         </varlistentry>
 676         <varlistentry>
 677           <term><command>reload <replaceable>PATTERN</replaceable>...</command></term>
 678
 679           <listitem>
 680             <para>Asks all units listed on the command line to reload
 681             their configuration. Note that this will reload the
 682             service-specific configuration, not the unit configuration
 683             file of systemd. If you want systemd to reload the
 684             configuration file of a unit, use the
 685             <command>daemon-reload</command> command. In other words:
 686             for the example case of Apache, this will reload Apache's
 687             <filename>httpd.conf</filename> in the web server, not the
 688             <filename>apache.service</filename> systemd unit
 689             file.</para>
 690
 691             <para>This command should not be confused with the
 692             <command>daemon-reload</command> command.</para>
 693           </listitem>
 694
 695         </varlistentry>
 696         <varlistentry>
 697           <term><command>restart <replaceable>PATTERN</replaceable>...</command></term>
 698
 699           <listitem>
 700             <para>Restart one or more units specified on the command
 701             line. If the units are not running yet, they will be
 702             started.</para>
 703           </listitem>
 704         </varlistentry>
 705         <varlistentry>
 706           <term><command>try-restart <replaceable>PATTERN</replaceable>...</command></term>
 707
 708           <listitem>
 709             <para>Restart one or more units specified on the command
 710             line if the units are running. This does nothing if units are not
 711             running.  Note that, for compatibility with Red Hat init
 712             scripts, <command>condrestart</command> is equivalent to this
 713             command.</para>
 714           </listitem>
 715         </varlistentry>
 716         <varlistentry>
 717           <term><command>reload-or-restart <replaceable>PATTERN</replaceable>...</command></term>
 718
 719           <listitem>
 720             <para>Reload one or more units if they support it. If not,
 721             restart them instead. If the units are not running yet, they
 722             will be started.</para>
 723           </listitem>
 724         </varlistentry>
 725         <varlistentry>
 726           <term><command>reload-or-try-restart <replaceable>PATTERN</replaceable>...</command></term>
 727
 728           <listitem>
 729             <para>Reload one or more units if they support it. If not,
 730             restart them instead. This does nothing if the units are not
 731             running. Note that, for compatibility with SysV init scripts,
 732             <command>force-reload</command> is equivalent to this
 733             command.</para>
 734           </listitem>
 735         </varlistentry>
 736         <varlistentry>
 737           <term><command>isolate <replaceable>NAME</replaceable></command></term>
 738
 739           <listitem>
 740             <para>Start the unit specified on the command line and its
 741             dependencies and stop all others. If a unit name with no
 742             extension is given, an extension of
 743             <literal>.target</literal> will be assumed.</para>
 744
 745             <para>This is similar to changing the runlevel in a
 746             traditional init system. The <command>isolate</command>
 747             command will immediately stop processes that are not enabled
 748             in the new unit, possibly including the graphical
 749             environment or terminal you are currently using.</para>
 750
 751             <para>Note that this is allowed only on units where
 752             <option>AllowIsolate=</option> is enabled. See
 753             <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 754             for details.</para>
 755           </listitem>
 756         </varlistentry>
 757         <varlistentry>
 758           <term><command>kill <replaceable>PATTERN</replaceable>...</command></term>
 759
 760           <listitem>
 761             <para>Send a signal to one or more processes of the
 762             unit. Use <option>--kill-who=</option> to select which
 763             process to kill. Use <option>--signal=</option> to select
 764             the signal to send.</para>
 765           </listitem>
 766         </varlistentry>
 767         <varlistentry>
 768           <term><command>is-active <replaceable>PATTERN</replaceable>...</command></term>
 769
 770           <listitem>
 771             <para>Check whether any of the specified units are active
 772             (i.e. running). Returns an exit code
 773             <constant>0</constant> if at least one is active, or
 774             non-zero otherwise. Unless <option>--quiet</option> is
 775             specified, this will also print the current unit state to
 776             standard output.</para>
 777           </listitem>
 778         </varlistentry>
 779         <varlistentry>
 780           <term><command>is-failed <replaceable>PATTERN</replaceable>...</command></term>
 781
 782           <listitem>
 783             <para>Check whether any of the specified units are in a
 784             "failed" state. Returns an exit code
 785             <constant>0</constant> if at least one has failed,
 786             non-zero otherwise. Unless <option>--quiet</option> is
 787             specified, this will also print the current unit state to
 788             standard output.</para>
 789           </listitem>
 790         </varlistentry>
 791         <varlistentry>
 792           <term><command>status</command> <optional><replaceable>PATTERN</replaceable>...|<replaceable>PID</replaceable>...]</optional></term>
 793
 794           <listitem>
 795             <para>Show terse runtime status information about one or
 796             more units, followed by most recent log data from the
 797             journal. If no units are specified, show system status. If
 798             combined with <option>--all</option>, also show the status of
 799             all units (subject to limitations specified with
 800             <option>-t</option>). If a PID is passed, show information
 801             about the unit the process belongs to.</para>
 802
 803             <para>This function is intended to generate human-readable
 804             output. If you are looking for computer-parsable output,
 805             use <command>show</command> instead. By default this
 806             function only shows 10 lines of output and ellipsizes
 807             lines to fit in the terminal window. This can be changes
 808             with <option>--lines</option> and <option>--full</option>,
 809             see above. In addition, <command>journalctl
 810             --unit=<replaceable>NAME</replaceable></command> or
 811             <command>journalctl
 812             --user-unit=<replaceable>NAME</replaceable></command> use
 813             a similar filter for messages and might be more
 814             convenient.
 815             </para>
 816           </listitem>
 817         </varlistentry>
 818         <varlistentry>
 819           <term><command>show</command> <optional><replaceable>PATTERN</replaceable>...|<replaceable>JOB</replaceable>...</optional></term>
 820
 821           <listitem>
 822             <para>Show properties of one or more units, jobs, or the
 823             manager itself. If no argument is specified, properties of
 824             the manager will be shown. If a unit name is specified,
 825             properties of the unit is shown, and if a job id is
 826             specified, properties of the job is shown. By default, empty
 827             properties are suppressed. Use <option>--all</option> to
 828             show those too. To select specific properties to show, use
 829             <option>--property=</option>. This command is intended to be
 830             used whenever computer-parsable output is required. Use
 831             <command>status</command> if you are looking for formatted
 832             human-readable output.</para>
 833           </listitem>
 834         </varlistentry>
 835         <varlistentry>
 836           <term><command>cat <replaceable>PATTERN</replaceable>...</command></term>
 837
 838           <listitem>
 839             <para>Show backing files of one or more units. Prints the
 840             "fragment" and "drop-ins" (source files) of units. Each
 841             file is preceded by a comment which includes the file
 842             name.</para>
 843           </listitem>
 844         </varlistentry>
 845         <varlistentry>
 846           <term><command>set-property <replaceable>NAME</replaceable> <replaceable>ASSIGNMENT</replaceable>...</command></term>
 847
 848           <listitem>
 849             <para>Set the specified unit properties at runtime where
 850             this is supported. This allows changing configuration
 851             parameter properties such as resource control settings at
 852             runtime. Not all properties may be changed at runtime, but
 853             many resource control settings (primarily those in
 854             <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>)
 855             may. The changes are applied instantly, and stored on disk
 856             for future boots, unless <option>--runtime</option> is
 857             passed, in which case the settings only apply until the
 858             next reboot. The syntax of the property assignment follows
 859             closely the syntax of assignments in unit files.</para>
 860
 861             <para>Example: <command>systemctl set-property foobar.service CPUShares=777</command></para>
 862
 863             <para>Note that this command allows changing multiple
 864             properties at the same time, which is preferable over
 865             setting them individually. Like unit file configuration
 866             settings, assigning the empty list to list parameters will
 867             reset the list.</para>
 868           </listitem>
 869         </varlistentry>
 870
 871         <varlistentry>
 872           <term><command>help <replaceable>PATTERN</replaceable>...|<replaceable>PID</replaceable>...</command></term>
 873
 874           <listitem>
 875             <para>Show manual pages for one or more units, if
 876             available. If a PID is given, the manual pages for the unit
 877             the process belongs to are shown.</para>
 878           </listitem>
 879         </varlistentry>
 880
 881         <varlistentry>
 882           <term><command>reset-failed [<replaceable>PATTERN</replaceable>...]</command></term>
 883
 884           <listitem>
 885             <para>Reset the <literal>failed</literal> state of the
 886             specified units, or if no unit name is passed, reset the state of all
 887             units. When a unit fails in some way (i.e. process exiting
 888             with non-zero error code, terminating abnormally or timing
 889             out), it will automatically enter the
 890             <literal>failed</literal> state and its exit code and status
 891             is recorded for introspection by the administrator until the
 892             service is restarted or reset with this command.</para>
 893           </listitem>
 894         </varlistentry>
 895
 896         <varlistentry>
 897           <term>
 898             <command>list-dependencies</command>
 899             <optional><replaceable>NAME</replaceable></optional>
 900           </term>
 901
 902           <listitem>
 903             <para>Shows units required and wanted by the specified
 904             unit. This recursively lists units following the
 905             <varname>Requires=</varname>,
 906             <varname>RequiresOverridable=</varname>,
 907             <varname>Requisite=</varname>,
 908             <varname>RequisiteOverridable=</varname>,
 909             <varname>Wants=</varname>, <varname>BindsTo=</varname>
 910             dependencies. If no unit is specified,
 911             <filename>default.target</filename> is implied.</para>
 912
 913             <para>By default, only target units are recursively
 914             expanded. When <option>--all</option> is passed, all other
 915             units are recursively expanded as well.</para>
 916
 917             <para>Options <option>--reverse</option>,
 918             <option>--after</option>, <option>--before</option>
 919             may be used to change what types of dependencies
 920             are shown.</para>
 921           </listitem>
 922         </varlistentry>
 923       </variablelist>
 924     </refsect2>
 925
 926     <refsect2>
 927       <title>Unit File Commands</title>
 928
 929       <variablelist>
 930         <varlistentry>
 931           <term><command>list-unit-files <optional><replaceable>PATTERN...</replaceable></optional></command></term>
 932
 933           <listitem>
 934             <para>List installed unit files. If one or more
 935             <replaceable>PATTERN</replaceable>s are specified, only
 936             units whose filename (just the last component of the path)
 937             matches one of them are shown.</para>
 938           </listitem>
 939         </varlistentry>
 940
 941         <varlistentry>
 942           <term><command>enable <replaceable>NAME</replaceable>...</command></term>
 943
 944           <listitem>
 945             <para>Enable one or more unit files or unit file instances,
 946             as specified on the command line. This will create a number
 947             of symlinks as encoded in the <literal>[Install]</literal>
 948             sections of the unit files. After the symlinks have been
 949             created, the systemd configuration is reloaded (in a way that
 950             is equivalent to <command>daemon-reload</command>) to ensure
 951             the changes are taken into account immediately. Note that
 952             this does <emphasis>not</emphasis> have the effect of also
 953             starting any of the units being enabled. If this
 954             is desired, either <option>--now</option> should be used
 955             together with this command, or an additional <command>start</command>
 956             command must be invoked for the unit. Also note that in case of
 957             instance enablement, symlinks named the same as instances
 958             are created in the install location, however they all point to the
 959             same template unit file.</para>
 960
 961             <para>This command will print the actions executed. This
 962             output may be suppressed by passing <option>--quiet</option>.
 963             </para>
 964
 965             <para>Note that this operation creates only the suggested
 966             symlinks for the units. While this command is the
 967             recommended way to manipulate the unit configuration
 968             directory, the administrator is free to make additional
 969             changes manually by placing or removing symlinks in the
 970             directory. This is particularly useful to create
 971             configurations that deviate from the suggested default
 972             installation. In this case, the administrator must make sure
 973             to invoke <command>daemon-reload</command> manually as
 974             necessary to ensure the changes are taken into account.
 975             </para>
 976
 977             <para>Enabling units should not be confused with starting
 978             (activating) units, as done by the <command>start</command>
 979             command. Enabling and starting units is orthogonal: units
 980             may be enabled without being started and started without
 981             being enabled. Enabling simply hooks the unit into various
 982             suggested places (for example, so that the unit is
 983             automatically started on boot or when a particular kind of
 984             hardware is plugged in). Starting actually spawns the daemon
 985             process (in case of service units), or binds the socket (in
 986             case of socket units), and so on.</para>
 987
 988             <para>Depending on whether <option>--system</option>,
 989             <option>--user</option>, <option>--runtime</option>,
 990             or <option>--global</option> is specified, this enables the unit
 991             for the system, for the calling user only, for only this boot of
 992             the system, or for all future logins of all users, or only this
 993             boot.  Note that in the last case, no systemd daemon
 994             configuration is reloaded.</para>
 995
 996             <para>Using <command>enable</command> on masked units
 997             results in an error.</para>
 998           </listitem>
 999         </varlistentry>
1000
1001         <varlistentry>
1002           <term><command>disable <replaceable>NAME</replaceable>...</command></term>
1003
1004           <listitem>
1005             <para>Disables one or more units. This removes all symlinks
1006             to the specified unit files from the unit configuration
1007             directory, and hence undoes the changes made by
1008             <command>enable</command>. Note however that this removes
1009             all symlinks to the unit files (i.e. including manual
1010             additions), not just those actually created by
1011             <command>enable</command>. This call implicitly reloads the
1012             systemd daemon configuration after completing the disabling
1013             of the units. Note that this command does not implicitly
1014             stop the units that are being disabled. If this is desired, either
1015             <option>--now</option> should be used together with this command, or
1016             an additional <command>stop</command> command should be executed
1017             afterwards.</para>
1018
1019             <para>This command will print the actions executed. This
1020             output may be suppressed by passing <option>--quiet</option>.
1021             </para>
1022
1023             <para>This command honors <option>--system</option>,
1024             <option>--user</option>, <option>--runtime</option> and
1025             <option>--global</option> in a similar way as
1026             <command>enable</command>.</para>
1027           </listitem>
1028         </varlistentry>
1029
1030         <varlistentry>
1031           <term><command>reenable <replaceable>NAME</replaceable>...</command></term>
1032
1033           <listitem>
1034             <para>Reenable one or more unit files, as specified on the
1035             command line. This is a combination of
1036             <command>disable</command> and <command>enable</command> and
1037             is useful to reset the symlinks a unit is enabled with to
1038             the defaults configured in the <literal>[Install]</literal>
1039             section of the unit file.</para>
1040           </listitem>
1041         </varlistentry>
1042
1043         <varlistentry>
1044           <term><command>preset <replaceable>NAME</replaceable>...</command></term>
1045
1046           <listitem>
1047             <para>Reset one or more unit files, as specified on the
1048             command line, to the defaults configured in the preset
1049             policy files. This has the same effect as
1050             <command>disable</command> or <command>enable</command>,
1051             depending how the unit is listed in the preset files.</para>
1052
1053             <para>Use <option>--preset-mode=</option> to control
1054             whether units shall be enabled and disabled, or only
1055             enabled, or only disabled.</para>
1056
1057             <para>For more information on the preset policy format,
1058             see
1059             <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
1060             For more information on the concept of presets, please
1061             consult the <ulink
1062             url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>
1063             document.</para>
1064           </listitem>
1065         </varlistentry>
1066
1067         <varlistentry>
1068           <term><command>preset-all</command></term>
1069
1070           <listitem>
1071             <para>Resets all installed unit files to the defaults
1072             configured in the preset policy file (see above).</para>
1073
1074             <para>Use <option>--preset-mode=</option> to control
1075             whether units shall be enabled and disabled, or only
1076             enabled, or only disabled.</para>
1077           </listitem>
1078         </varlistentry>
1079
1080         <varlistentry>
1081           <term><command>is-enabled <replaceable>NAME</replaceable>...</command></term>
1082
1083           <listitem>
1084             <para>Checks whether any of the specified unit files are
1085             enabled (as with <command>enable</command>). Returns an
1086             exit code of 0 if at least one is enabled, non-zero
1087             otherwise. Prints the current enable status (see table).
1088             To suppress this output, use <option>--quiet</option>.
1089             </para>
1090
1091             <table>
1092               <title>
1093                 <command>is-enabled</command> output
1094               </title>
1095
1096               <tgroup cols='3'>
1097                 <thead>
1098                   <row>
1099                     <entry>Printed string</entry>
1100                     <entry>Meaning</entry>
1101                     <entry>Return value</entry>
1102                   </row>
1103                 </thead>
1104                 <tbody>
1105                   <row>
1106                     <entry><literal>enabled</literal></entry>
1107                     <entry morerows='1'>Enabled through a symlink in <filename>.wants</filename> directory (permanently or just in <filename>/run</filename>).</entry>
1108                     <entry morerows='1'>0</entry>
1109                   </row>
1110                   <row>
1111                     <entry><literal>enabled-runtime</literal></entry>
1112                   </row>
1113                   <row>
1114                     <entry><literal>linked</literal></entry>
1115                     <entry morerows='1'>Made available through a symlink to the unit file (permanently or just in <filename>/run</filename>).</entry>
1116                     <entry morerows='1'>1</entry>
1117                   </row>
1118                   <row>
1119                     <entry><literal>linked-runtime</literal></entry>
1120                   </row>
1121                   <row>
1122                     <entry><literal>masked</literal></entry>
1123                     <entry morerows='1'>Disabled entirely (permanently or just in <filename>/run</filename>).</entry>
1124                     <entry morerows='1'>1</entry>
1125                   </row>
1126                   <row>
1127                     <entry><literal>masked-runtime</literal></entry>
1128                   </row>
1129                   <row>
1130                     <entry><literal>static</literal></entry>
1131                     <entry>Unit file is not enabled, and has no provisions for enabling in the <literal>[Install]</literal> section.</entry>
1132                     <entry>0</entry>
1133                   </row>
1134                   <row>
1135                     <entry><literal>indirect</literal></entry>
1136                     <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>
1137                     <entry>0</entry>
1138                   </row>
1139                   <row>
1140                     <entry><literal>disabled</literal></entry>
1141                     <entry>Unit file is not enabled.</entry>
1142                     <entry>1</entry>
1143                   </row>
1144                 </tbody>
1145               </tgroup>
1146             </table>
1147
1148           </listitem>
1149         </varlistentry>
1150
1151         <varlistentry>
1152           <term><command>mask <replaceable>NAME</replaceable>...</command></term>
1153
1154           <listitem>
1155             <para>Mask one or more unit files, as specified on the
1156             command line. This will link these units to
1157             <filename>/dev/null</filename>, making it impossible to
1158             start them. This is a stronger version of
1159             <command>disable</command>, since it prohibits all kinds of
1160             activation of the unit, including enablement and manual
1161             activation. Use this option with care. This honors the
1162             <option>--runtime</option> option to only mask temporarily
1163             until the next reboot of the system. The <option>--now</option>
1164             option can be used to ensure that the units are also stopped.</para>
1165           </listitem>
1166         </varlistentry>
1167
1168         <varlistentry>
1169           <term><command>unmask <replaceable>NAME</replaceable>...</command></term>
1170
1171           <listitem>
1172             <para>Unmask one or more unit files, as specified on the
1173             command line. This will undo the effect of
1174             <command>mask</command>.</para>
1175           </listitem>
1176         </varlistentry>
1177
1178         <varlistentry>
1179           <term><command>link <replaceable>FILENAME</replaceable>...</command></term>
1180
1181           <listitem>
1182             <para>Link a unit file that is not in the unit file search
1183             paths into the unit file search path. This requires an
1184             absolute path to a unit file. The effect of this can be
1185             undone with <command>disable</command>. The effect of this
1186             command is that a unit file is available for
1187             <command>start</command> and other commands although it
1188             is not installed directly in the unit search path.</para>
1189           </listitem>
1190         </varlistentry>
1191
1192         <varlistentry>
1193           <term><command>add-wants <replaceable>TARGET</replaceable>
1194           <replaceable>NAME</replaceable>...</command></term>
1195           <term><command>add-requires <replaceable>TARGET</replaceable>
1196           <replaceable>NAME</replaceable>...</command></term>
1197
1198           <listitem>
1199             <para>Adds <literal>Wants=</literal> or <literal>Requires=</literal>
1200             dependency, respectively, to the specified
1201             <replaceable>TARGET</replaceable> for one or more units. </para>
1202
1203             <para>This command honors <option>--system</option>,
1204             <option>--user</option>, <option>--runtime</option> and
1205             <option>--global</option> in a similar way as
1206             <command>enable</command>.</para>
1207
1208           </listitem>
1209         </varlistentry>
1210
1211         <varlistentry>
1212           <term><command>edit <replaceable>NAME</replaceable>...</command></term>
1213
1214           <listitem>
1215             <para>Edit a drop-in snippet or a whole replacement file if
1216             <option>--full</option> is specified, to extend or override the
1217             specified unit.</para>
1218
1219             <para>Depending on whether <option>--system</option> (the default),
1220             <option>--user</option>, or <option>--global</option> is specified,
1221             this creates a drop-in file for each unit either for the system,
1222             for the calling user or for all futures logins of all users. Then,
1223             the editor (see the "Environment" section below) is invoked on
1224             temporary files which will be written to the real location if the
1225             editor exits successfully.</para>
1226
1227             <para>If <option>--full</option> is specified, this will copy the
1228             original units instead of creating drop-in files.</para>
1229
1230             <para>If <option>--runtime</option> is specified, the changes will
1231             be made temporarily in <filename>/run</filename> and they will be
1232             lost on the next reboot.</para>
1233
1234             <para>If the temporary file is empty upon exit the modification of
1235             the related unit is canceled</para>
1236
1237             <para>After the units have been edited, systemd configuration is
1238             reloaded (in a way that is equivalent to <command>daemon-reload</command>).
1239             </para>
1240
1241             <para>Note that this command cannot be used to remotely edit units
1242             and that you cannot temporarily edit units which are in
1243             <filename>/etc</filename> since they take precedence over
1244             <filename>/run</filename>.</para>
1245           </listitem>
1246         </varlistentry>
1247
1248         <varlistentry>
1249           <term><command>get-default</command></term>
1250
1251           <listitem>
1252             <para>Return the default target to boot into. This returns
1253             the target unit name <filename>default.target</filename>
1254             is aliased (symlinked) to.</para>
1255           </listitem>
1256         </varlistentry>
1257
1258         <varlistentry>
1259           <term><command>set-default <replaceable>NAME</replaceable></command></term>
1260
1261           <listitem>
1262             <para>Set the default target to boot into. This sets
1263             (symlinks) the <filename>default.target</filename> alias
1264             to the given target unit.</para>
1265           </listitem>
1266         </varlistentry>
1267
1268       </variablelist>
1269     </refsect2>
1270
1271     <refsect2>
1272       <title>Machine Commands</title>
1273
1274       <variablelist>
1275         <varlistentry>
1276           <term><command>list-machines <optional><replaceable>PATTERN</replaceable>...</optional></command></term>
1277
1278           <listitem>
1279             <para>List the host and all running local containers with
1280             their state. If one or more
1281             <replaceable>PATTERN</replaceable>s are specified, only
1282             containers matching one of them are shown.
1283             </para>
1284           </listitem>
1285         </varlistentry>
1286       </variablelist>
1287     </refsect2>
1288
1289     <refsect2>
1290       <title>Job Commands</title>
1291
1292       <variablelist>
1293         <varlistentry>
1294           <term><command>list-jobs <optional><replaceable>PATTERN...</replaceable></optional></command></term>
1295
1296           <listitem>
1297             <para>List jobs that are in progress. If one or more
1298             <replaceable>PATTERN</replaceable>s are specified, only
1299             jobs for units matching one of them are shown.</para>
1300           </listitem>
1301         </varlistentry>
1302         <varlistentry>
1303           <term><command>cancel <replaceable>JOB</replaceable>...</command></term>
1304
1305           <listitem>
1306             <para>Cancel one or more jobs specified on the command line
1307             by their numeric job IDs. If no job ID is specified, cancel
1308             all pending jobs.</para>
1309           </listitem>
1310         </varlistentry>
1311       </variablelist>
1312     </refsect2>
1313
1314     <refsect2>
1315       <title>Snapshot Commands</title>
1316
1317       <variablelist>
1318         <varlistentry>
1319           <term><command>snapshot <optional><replaceable>NAME</replaceable></optional></command></term>
1320
1321           <listitem>
1322             <para>Create a snapshot. If a snapshot name is specified,
1323             the new snapshot will be named after it. If none is
1324             specified, an automatic snapshot name is generated. In
1325             either case, the snapshot name used is printed to standard
1326             output, unless <option>--quiet</option> is specified.
1327             </para>
1328
1329             <para>A snapshot refers to a saved state of the systemd
1330             manager. It is implemented itself as a unit that is
1331             generated dynamically with this command and has dependencies
1332             on all units active at the time. At a later time, the user
1333             may return to this state by using the
1334             <command>isolate</command> command on the snapshot unit.
1335             </para>
1336
1337             <para>Snapshots are only useful for saving and restoring
1338             which units are running or are stopped, they do not
1339             save/restore any other state. Snapshots are dynamic and lost
1340             on reboot.</para>
1341           </listitem>
1342         </varlistentry>
1343         <varlistentry>
1344           <term><command>delete <replaceable>PATTERN</replaceable>...</command></term>
1345
1346           <listitem>
1347             <para>Remove a snapshot previously created with
1348             <command>snapshot</command>.</para>
1349           </listitem>
1350         </varlistentry>
1351       </variablelist>
1352     </refsect2>
1353
1354     <refsect2>
1355       <title>Environment Commands</title>
1356
1357       <variablelist>
1358         <varlistentry>
1359           <term><command>show-environment</command></term>
1360
1361           <listitem>
1362             <para>Dump the systemd manager environment block. The
1363             environment block will be dumped in straight-forward form
1364             suitable for sourcing into a shell script. This environment
1365             block will be passed to all processes the manager
1366             spawns.</para>
1367           </listitem>
1368         </varlistentry>
1369         <varlistentry>
1370           <term><command>set-environment <replaceable>VARIABLE=VALUE</replaceable>...</command></term>
1371
1372           <listitem>
1373             <para>Set one or more systemd manager environment variables,
1374             as specified on the command line.</para>
1375           </listitem>
1376         </varlistentry>
1377         <varlistentry>
1378           <term><command>unset-environment <replaceable>VARIABLE</replaceable>...</command></term>
1379
1380           <listitem>
1381             <para>Unset one or more systemd manager environment
1382             variables. If only a variable name is specified, it will be
1383             removed regardless of its value. If a variable and a value
1384             are specified, the variable is only removed if it has the
1385             specified value.</para>
1386           </listitem>
1387         </varlistentry>
1388         <varlistentry>
1389           <term>
1390             <command>import-environment</command>
1391             <optional><replaceable>VARIABLE...</replaceable></optional>
1392           </term>
1393
1394           <listitem>
1395             <para>Import all, one or more environment variables set on
1396             the client into the systemd manager environment block. If
1397             no arguments are passed, the entire environment block is
1398             imported. Otherwise, a list of one or more environment
1399             variable names should be passed, whose client-side values
1400             are then imported into the manager's environment
1401             block.</para>
1402           </listitem>
1403         </varlistentry>
1404       </variablelist>
1405     </refsect2>
1406
1407     <refsect2>
1408       <title>Manager Lifecycle Commands</title>
1409
1410       <variablelist>
1411         <varlistentry>
1412           <term><command>daemon-reload</command></term>
1413
1414           <listitem>
1415             <para>Reload systemd manager configuration. This will
1416             rerun all generators (see
1417             <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>),
1418             reload all unit files, and recreate the entire dependency
1419             tree. While the daemon is being reloaded, all sockets
1420             systemd listens on behalf of user configuration will stay
1421             accessible.</para>
1422
1423             <para>This command should not be confused with the
1424             <command>reload</command> command.</para>
1425           </listitem>
1426         </varlistentry>
1427         <varlistentry>
1428           <term><command>daemon-reexec</command></term>
1429
1430           <listitem>
1431             <para>Reexecute the systemd manager. This will serialize the
1432             manager state, reexecute the process and deserialize the
1433             state again. This command is of little use except for
1434             debugging and package upgrades. Sometimes, it might be
1435             helpful as a heavy-weight <command>daemon-reload</command>.
1436             While the daemon is being reexecuted, all sockets systemd listening
1437             on behalf of user configuration will stay accessible.
1438             </para>
1439           </listitem>
1440         </varlistentry>
1441       </variablelist>
1442     </refsect2>
1443
1444     <refsect2>
1445       <title>System Commands</title>
1446
1447       <variablelist>
1448         <varlistentry>
1449           <term><command>is-system-running</command></term>
1450
1451           <listitem>
1452             <para>Checks whether the system is operational. This
1453             returns success when the system is fully up and running,
1454             meaning not in startup, shutdown or maintenance
1455             mode. Failure is returned otherwise. In addition, the
1456             current state is printed in a short string to standard
1457             output, see table below. Use <option>--quiet</option> to
1458             suppress this output.</para>
1459
1460             <table>
1461               <title>Manager Operational States</title>
1462               <tgroup cols='2'>
1463                 <colspec colname='name' />
1464                 <colspec colname='description' />
1465                 <thead>
1466                   <row>
1467                     <entry>Name</entry>
1468                     <entry>Description</entry>
1469                   </row>
1470                 </thead>
1471                 <tbody>
1472                   <row>
1473                     <entry><varname>initializing</varname></entry>
1474                     <entry><para>Early bootup, before
1475                     <filename>basic.target</filename> is reached
1476                     or the <varname>maintenance</varname> state entered.
1477                     </para></entry>
1478                   </row>
1479                   <row>
1480                     <entry><varname>starting</varname></entry>
1481                     <entry><para>Late bootup, before the job queue
1482                     becomes idle for the first time, or one of the
1483                     rescue targets are reached.</para></entry>
1484                   </row>
1485                   <row>
1486                     <entry><varname>running</varname></entry>
1487                     <entry><para>The system is fully
1488                     operational.</para></entry>
1489                   </row>
1490                   <row>
1491                     <entry><varname>degraded</varname></entry>
1492                     <entry><para>The system is operational but one or more
1493                     units failed.</para></entry>
1494                   </row>
1495                   <row>
1496                     <entry><varname>maintenance</varname></entry>
1497                     <entry><para>The rescue or emergency target is
1498                     active.</para></entry>
1499                   </row>
1500                   <row>
1501                     <entry><varname>stopping</varname></entry>
1502                     <entry><para>The manager is shutting
1503                     down.</para></entry>
1504                   </row>
1505                 </tbody>
1506               </tgroup>
1507             </table>
1508           </listitem>
1509         </varlistentry>
1510
1511         <varlistentry>
1512           <term><command>default</command></term>
1513
1514           <listitem>
1515             <para>Enter default mode. This is mostly equivalent to
1516             <command>isolate default.target</command>.</para>
1517           </listitem>
1518         </varlistentry>
1519
1520         <varlistentry>
1521           <term><command>rescue</command></term>
1522
1523           <listitem>
1524             <para>Enter rescue mode. This is mostly equivalent to
1525             <command>isolate rescue.target</command>, but also prints a
1526             wall message to all users.</para>
1527           </listitem>
1528         </varlistentry>
1529         <varlistentry>
1530           <term><command>emergency</command></term>
1531
1532           <listitem>
1533             <para>Enter emergency mode. This is mostly equivalent to
1534             <command>isolate emergency.target</command>, but also prints
1535             a wall message to all users.</para>
1536           </listitem>
1537         </varlistentry>
1538         <varlistentry>
1539           <term><command>halt</command></term>
1540
1541           <listitem>
1542             <para>Shut down and halt the system. This is mostly equivalent to
1543             <command>start halt.target --job-mode=replace-irreversibly</command>, but also
1544             prints a wall message to all users.  If combined with
1545             <option>--force</option>, shutdown of all running services is
1546             skipped, however all processes are killed and all file
1547             systems are unmounted or mounted read-only, immediately
1548             followed by the system halt.  If <option>--force</option> is
1549             specified twice, the operation is immediately executed
1550             without terminating any processes or unmounting any file
1551             systems. This may result in data loss.</para>
1552           </listitem>
1553         </varlistentry>
1554         <varlistentry>
1555           <term><command>poweroff</command></term>
1556
1557           <listitem>
1558             <para>Shut down and power-off the system. This is mostly
1559             equivalent to <command>start poweroff.target --job-mode=replace-irreversibly</command>,
1560             but also prints a wall message to all users. If combined with
1561             <option>--force</option>, shutdown of all running services is
1562             skipped, however all processes are killed and all file
1563             systems are unmounted or mounted read-only, immediately
1564             followed by the powering off. If <option>--force</option> is
1565             specified twice, the operation is immediately executed
1566             without terminating any processes or unmounting any file
1567             systems. This may result in data loss.</para>
1568           </listitem>
1569         </varlistentry>
1570         <varlistentry>
1571           <term><command>reboot <optional><replaceable>arg</replaceable></optional></command></term>
1572
1573           <listitem>
1574             <para>Shut down and reboot the system. This is mostly
1575             equivalent to <command>start reboot.target --job-mode=replace-irreversibly</command>,
1576             but also prints a wall message to all users. If combined with
1577             <option>--force</option>, shutdown of all running services is
1578             skipped, however all processes are killed and all file
1579             systems are unmounted or mounted read-only, immediately
1580             followed by the reboot. If <option>--force</option> is
1581             specified twice, the operation is immediately executed
1582             without terminating any processes or unmounting any file
1583             systems. This may result in data loss.</para>
1584
1585             <para>If the optional argument
1586             <replaceable>arg</replaceable> is given, it will be passed
1587             as the optional argument to the
1588             <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
1589             system call. The value is architecture and firmware
1590             specific. As an example, <literal>recovery</literal> might
1591             be used to trigger system recovery, and
1592             <literal>fota</literal> might be used to trigger a
1593             <quote>firmware over the air</quote> update.</para>
1594           </listitem>
1595         </varlistentry>
1596
1597         <varlistentry>
1598           <term><command>kexec</command></term>
1599
1600           <listitem>
1601             <para>Shut down and reboot the system via kexec. This is
1602             mostly equivalent to <command>start kexec.target --job-mode=replace-irreversibly</command>,
1603             but also prints a wall message to all users. If combined
1604             with <option>--force</option>, shutdown of all running
1605             services is skipped, however all processes are killed and
1606             all file systems are unmounted or mounted read-only,
1607             immediately followed by the reboot.</para>
1608           </listitem>
1609         </varlistentry>
1610
1611         <varlistentry>
1612           <term><command>exit</command></term>
1613
1614           <listitem>
1615             <para>Ask the systemd manager to quit. This is only
1616             supported for user service managers (i.e. in conjunction
1617             with the <option>--user</option> option) and will fail
1618             otherwise.</para>
1619           </listitem>
1620         </varlistentry>
1621
1622         <varlistentry>
1623           <term><command>switch-root <replaceable>ROOT</replaceable> <optional><replaceable>INIT</replaceable></optional></command></term>
1624
1625           <listitem>
1626             <para>Switches to a different root directory and executes a
1627             new system manager process below it. This is intended for
1628             usage in initial RAM disks ("initrd"), and will transition
1629             from the initrd's system manager process (a.k.a "init"
1630             process) to the main system manager process. This call takes two
1631             arguments: the directory that is to become the new root directory, and
1632             the path to the new system manager binary below it to
1633             execute as PID 1. If the latter is omitted or the empty
1634             string, a systemd binary will automatically be searched for
1635             and used as init. If the system manager path is omitted or
1636             equal to the empty string, the state of the initrd's system
1637             manager process is passed to the main system manager, which
1638             allows later introspection of the state of the services
1639             involved in the initrd boot.</para>
1640           </listitem>
1641         </varlistentry>
1642
1643         <varlistentry>
1644           <term><command>suspend</command></term>
1645
1646           <listitem>
1647             <para>Suspend the system. This will trigger activation of
1648             the special <filename>suspend.target</filename> target.
1649             </para>
1650           </listitem>
1651         </varlistentry>
1652
1653         <varlistentry>
1654           <term><command>hibernate</command></term>
1655
1656           <listitem>
1657             <para>Hibernate the system. This will trigger activation of
1658             the special <filename>hibernate.target</filename> target.
1659             </para>
1660           </listitem>
1661         </varlistentry>
1662
1663         <varlistentry>
1664           <term><command>hybrid-sleep</command></term>
1665
1666           <listitem>
1667             <para>Hibernate and suspend the system. This will trigger
1668             activation of the special
1669             <filename>hybrid-sleep.target</filename> target.</para>
1670           </listitem>
1671         </varlistentry>
1672       </variablelist>
1673     </refsect2>
1674
1675     <refsect2>
1676       <title>Parameter Syntax</title>
1677
1678       <para>Unit commands listed above take either a single unit name
1679       (designated as <replaceable>NAME</replaceable>), or multiple
1680       unit specifications (designated as
1681       <replaceable>PATTERN</replaceable>...). In the first case, the
1682       unit name with or without a suffix must be given. If the suffix
1683       is not specified, systemctl will append a suitable suffix,
1684       <literal>.service</literal> by default, and a type-specific
1685       suffix in case of commands which operate only on specific unit
1686       types. For example,
1687       <programlisting># systemctl start sshd</programlisting> and
1688       <programlisting># systemctl start sshd.service</programlisting>
1689       are equivalent, as are
1690       <programlisting># systemctl isolate default</programlisting>
1691       and
1692       <programlisting># systemctl isolate default.target</programlisting>
1693       Note that (absolute) paths to device nodes are automatically
1694       converted to device unit names, and other (absolute) paths to
1695       mount unit names.
1696       <programlisting># systemctl status /dev/sda
1697 # systemctl status /home</programlisting>
1698       are equivalent to:
1699       <programlisting># systemctl status dev-sda.device
1700 # systemctl status home.mount</programlisting>
1701       In the second case, shell-style globs will be matched against
1702       currently loaded units; literal unit names, with or without
1703       a suffix, will be treated as in the first case. This means that
1704       literal unit names always refer to exactly one unit, but globs
1705       may match zero units and this is not considered an error.</para>
1706
1707       <para>Glob patterns use
1708       <citerefentry project='man-pages'><refentrytitle>fnmatch</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
1709       so normal shell-style globbing rules are used, and
1710       <literal>*</literal>, <literal>?</literal>,
1711       <literal>[]</literal> may be used. See
1712       <citerefentry project='man-pages'><refentrytitle>glob</refentrytitle><manvolnum>7</manvolnum></citerefentry>
1713       for more details. The patterns are matched against the names of
1714       currently loaded units, and patterns which do not match anything
1715       are silently skipped. For example:
1716       <programlisting># systemctl stop sshd@*.service</programlisting>
1717       will stop all <filename>sshd@.service</filename> instances.
1718       </para>
1719
1720       <para>For unit file commands, the specified
1721       <replaceable>NAME</replaceable> should be the full name of the
1722       unit file, or the absolute path to the unit file:
1723       <programlisting># systemctl enable foo.service</programlisting>
1724       or
1725       <programlisting># systemctl link /path/to/foo.service</programlisting>
1726       </para>
1727     </refsect2>
1728
1729   </refsect1>
1730
1731   <refsect1>
1732     <title>Exit status</title>
1733
1734     <para>On success, 0 is returned, a non-zero failure
1735     code otherwise.</para>
1736   </refsect1>
1737
1738   <refsect1>
1739     <title>Environment</title>
1740
1741     <variablelist class='environment-variables'>
1742       <varlistentry>
1743         <term><varname>$SYSTEMD_EDITOR</varname></term>
1744
1745         <listitem><para>Editor to use when editing units; overrides
1746         <varname>$EDITOR</varname> and <varname>$VISUAL</varname>. If neither
1747         <varname>$SYSTEMD_EDITOR</varname> nor <varname>$EDITOR</varname> nor
1748         <varname>$VISUAL</varname> are present or if it is set to an empty
1749         string or if their execution failed, systemctl will try to execute well
1750         known editors in this order:
1751         <citerefentry project='die-net'><refentrytitle>editor</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1752         <citerefentry project='die-net'><refentrytitle>nano</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1753         <citerefentry project='die-net'><refentrytitle>vim</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1754         <citerefentry project='die-net'><refentrytitle>vi</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
1755         </para></listitem>
1756       </varlistentry>
1757     </variablelist>
1758     <xi:include href="less-variables.xml" xpointer="pager"/>
1759     <xi:include href="less-variables.xml" xpointer="less"/>
1760   </refsect1>
1761
1762   <refsect1>
1763     <title>See Also</title>
1764     <para>
1765       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1766       <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1767       <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1768       <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1769       <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1770       <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1771       <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1772       <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1773       <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1774       <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1775       <citerefentry project='man-pages'><refentrytitle>glob</refentrytitle><manvolnum>7</manvolnum></citerefentry>
1776     </para>
1777   </refsect1>
1778
1779 </refentry>