man/systemctl.xml

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