man/systemctl.xml

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