man/systemctl.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   6   This file is part of systemd.
   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 General Public License as published by
  12   the Free Software Foundation; either version 2 of the License, or
  13   (at your option) any later version.
  14
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  18   General Public License for more details.
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  23
  24 <refentry id="systemctl">
  25
  26         <refentryinfo>
  27                 <title>systemctl</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>systemctl</refentrytitle>
  42                 <manvolnum>1</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemctl</refname>
  47                 <refpurpose>Control the systemd system and service manager</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <cmdsynopsis>
  52                         <command>systemctl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg> <arg choice="opt" rep="repeat">NAME</arg></command>
  53                 </cmdsynopsis>
  54         </refsynopsisdiv>
  55
  56         <refsect1>
  57                 <title>Description</title>
  58
  59                 <para><command>systemctl</command> may be used to
  60                 introspect and control the state of the
  61                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  62                 system and service manager.</para>
  63         </refsect1>
  64
  65         <refsect1>
  66                 <title>Options</title>
  67
  68                 <para>The following options are understood:</para>
  69
  70                 <variablelist>
  71                         <varlistentry>
  72                                 <term><option>--help</option></term>
  73                                 <term><option>-h</option></term>
  74
  75                                 <listitem><para>Prints a short help
  76                                 text and exits.</para></listitem>
  77                         </varlistentry>
  78
  79                         <varlistentry>
  80                                 <term><option>--version</option></term>
  81
  82                                 <listitem><para>Prints a short version
  83                                 string and exits.</para></listitem>
  84                         </varlistentry>
  85
  86                         <varlistentry>
  87                                 <term><option>--type=</option></term>
  88                                 <term><option>-t</option></term>
  89
  90                                 <listitem><para>When listing units,
  91                                 limit display to certain unit
  92                                 types. If not specified units of all
  93                                 types will be shown. The argument
  94                                 should be a unit type name such as
  95                                 <option>service</option>,
  96                                 <option>socket</option> and
  97                                 similar.</para></listitem>
  98                         </varlistentry>
  99
 100                         <varlistentry>
 101                                 <term><option>--property=</option></term>
 102                                 <term><option>-p</option></term>
 103
 104                                 <listitem><para>When showing
 105                                 unit/job/manager properties, limit
 106                                 display to certain properties as
 107                                 specified as argument. If not
 108                                 specified all set properties are
 109                                 shown. The argument should be a
 110                                 property name, such as
 111                                 <literal>MainPID</literal>. If
 112                                 specified more than once all
 113                                 properties with the specified names
 114                                 are shown.</para></listitem>
 115                         </varlistentry>
 116
 117                         <varlistentry>
 118                                 <term><option>--all</option></term>
 119                                 <term><option>-a</option></term>
 120
 121                                 <listitem><para>When listing units,
 122                                 show all units, regardless of their
 123                                 state, including inactive units. When
 124                                 showing unit/job/manager properties,
 125                                 show all properties regardless whether
 126                                 they are set or not.</para></listitem>
 127                         </varlistentry>
 128
 129                         <varlistentry>
 130                                 <term><option>--failed</option></term>
 131
 132                                 <listitem><para>When listing units,
 133                                 show only failed units. Do not confuse
 134                                 with
 135                                 <option>--fail</option>.</para></listitem>
 136                         </varlistentry>
 137
 138                         <varlistentry>
 139                                 <term><option>--full</option></term>
 140
 141                                 <listitem><para>Do not ellipsize unit
 142                                 names and truncate unit descriptions
 143                                 in the output of
 144                                 <command>list-units</command> and
 145                                 <command>list-jobs</command>.</para></listitem>
 146                         </varlistentry>
 147
 148                         <varlistentry>
 149                                 <term><option>--fail</option></term>
 150
 151                                 <listitem><para>If the requested
 152                                 operation conflicts with a pending
 153                                 unfinished job, fail the command. If
 154                                 this is not specified the requested
 155                                 operation will replace the pending job,
 156                                 if necessary. Do not confuse
 157                                 with
 158                                 <option>--failed</option>.</para></listitem>
 159                         </varlistentry>
 160
 161                         <varlistentry>
 162                                 <term><option>--ignore-dependencies</option></term>
 163
 164                                 <listitem><para>When enqueuing a new
 165                                 job ignore all its dependencies and
 166                                 execute it immediately. If passed no
 167                                 required units of the unit passed will
 168                                 be pulled in, and no ordering
 169                                 dependencies will be honoured. This is
 170                                 mostly a debugging and rescue tool for
 171                                 the administrator and should not be
 172                                 used by
 173                                 applications.</para></listitem>
 174                         </varlistentry>
 175
 176                         <varlistentry>
 177                                 <term><option>--quiet</option></term>
 178                                 <term><option>-q</option></term>
 179
 180                                 <listitem><para>Suppress output to
 181                                 STDOUT in
 182                                 <command>snapshot</command>,
 183                                 <command>is-active</command>,
 184                                 <command>enable</command> and
 185                                 <command>disable</command>.</para></listitem>
 186                         </varlistentry>
 187
 188                         <varlistentry>
 189                                 <term><option>--no-block</option></term>
 190
 191                                 <listitem><para>Do not synchronously wait for
 192                                 the requested operation to finish. If this is
 193                                 not specified the job will be verified,
 194                                 enqueued and <command>systemctl</command> will
 195                                 wait until it is completed. By passing this
 196                                 argument it is only verified and
 197                                 enqueued.</para></listitem>
 198                         </varlistentry>
 199
 200                         <varlistentry>
 201                                 <term><option>--no-pager</option></term>
 202
 203                                 <listitem><para>Do not pipe output into a
 204                                 pager.</para></listitem>
 205                         </varlistentry>
 206
 207                         <varlistentry>
 208                                 <term><option>--system</option></term>
 209
 210                                 <listitem><para>Talk to the systemd
 211                                 system manager. (Default)</para></listitem>
 212                         </varlistentry>
 213
 214                         <varlistentry>
 215                                 <term><option>--user</option></term>
 216
 217                                 <listitem><para>Talk to the systemd
 218                                 manager of the calling user.</para></listitem>
 219                         </varlistentry>
 220
 221                         <varlistentry>
 222                                 <term><option>--order</option></term>
 223                                 <term><option>--require</option></term>
 224
 225                                 <listitem><para>When used in
 226                                 conjunction with the
 227                                 <command>dot</command> command (see
 228                                 below), selects which dependencies are
 229                                 shown in the dependency graph. If
 230                                 <option>--order</option> is passed
 231                                 only dependencies of type
 232                                 <varname>After=</varname> or
 233                                 <varname>Before=</varname> are
 234                                 shown. If <option>--require</option>
 235                                 is passed only dependencies of type
 236                                 <varname>Requires=</varname>,
 237                                 <varname>RequiresOverridable=</varname>,
 238                                 <varname>Requisite=</varname>,
 239                                 <varname>RequisiteOverridable=</varname>,
 240                                 <varname>Wants=</varname> and
 241                                 <varname>Conflicts=</varname> are
 242                                 shown. If neither is passed, shows
 243                                 dependencies of all these
 244                                 types.</para></listitem>
 245                         </varlistentry>
 246
 247                         <varlistentry>
 248                                 <term><option>--no-wall</option></term>
 249
 250                                 <listitem><para>Don't send wall
 251                                 message before
 252                                 halt, power-off, reboot.</para></listitem>
 253                         </varlistentry>
 254
 255                         <varlistentry>
 256                                 <term><option>--global</option></term>
 257
 258                                 <listitem><para>When used with
 259                                 <command>enable</command> and
 260                                 <command>disable</command>, operate on the
 261                                 global user configuration
 262                                 directory, thus enabling or disabling
 263                                 a unit file globally for all future
 264                                 logins of all users.</para></listitem>
 265                         </varlistentry>
 266
 267                         <varlistentry>
 268                                 <term><option>--no-reload</option></term>
 269
 270                                 <listitem><para>When used with
 271                                 <command>enable</command> and
 272                                 <command>disable</command>, do not
 273                                 implicitly reload daemon configuration
 274                                 after executing the
 275                                 changes.</para></listitem>
 276                         </varlistentry>
 277
 278                         <varlistentry>
 279                                 <term><option>--no-ask-password</option></term>
 280
 281                                 <listitem><para>When used with
 282                                 <command>start</command> and related
 283                                 commands, disables asking for
 284                                 passwords. Background services may
 285                                 require input of a password or
 286                                 passphrase string, for example to
 287                                 unlock system hard disks or
 288                                 cryptographic certificates. Unless
 289                                 this option is specified and the
 290                                 command is invoked from a terminal
 291                                 <command>systemctl</command> will
 292                                 query the user on the terminal for the
 293                                 necessary secrets. Use this option to
 294                                 switch this behavior off. In this
 295                                 case the password must be supplied by
 296                                 some other means (for example
 297                                 graphical password agents) or the
 298                                 service might fail.</para></listitem>
 299                         </varlistentry>
 300
 301                         <varlistentry>
 302                                 <term><option>--kill-who=</option></term>
 303
 304                                 <listitem><para>When used with
 305                                 <command>kill</command>, choose which
 306                                 processes to kill. Must be one of
 307                                 <option>main</option>,
 308                                 <option>control</option> or
 309                                 <option>all</option> to select whether
 310                                 to kill only the main process of the
 311                                 unit, the control process or all
 312                                 processes of the unit. If omitted
 313                                 defaults to
 314                                 <option>all</option>.</para></listitem>
 315                         </varlistentry>
 316
 317                         <varlistentry>
 318                                 <term><option>--signal=</option></term>
 319                                 <term><option>-s</option></term>
 320
 321                                 <listitem><para>When used with
 322                                 <command>kill</command>, choose which
 323                                 signal to send to selected
 324                                 processes. Must be one of the well
 325                                 known signal specifiers such as
 326                                 SIGTERM, SIGINT or SIGSTOP. If
 327                                 omitted defaults to
 328                                 <option>SIGTERM</option>.</para></listitem>
 329                         </varlistentry>
 330
 331                         <varlistentry>
 332                                 <term><option>--force</option></term>
 333                                 <term><option>-f</option></term>
 334
 335                                 <listitem><para>When used with
 336                                 <command>enable</command>, override any
 337                                 existing conflicting
 338                                 symlinks.</para></listitem>
 339
 340                                 <listitem><para>When used with
 341                                 <command>halt</command>,
 342                                 <command>poweroff</command>,
 343                                 <command>reboot</command> or
 344                                 <command>kexec</command> execute
 345                                 selected operation without shutting
 346                                 down all units. However, all processes
 347                                 will be killed forcibly and all file
 348                                 systems are unmounted or remounted
 349                                 read-only. This is hence a drastic but
 350                                 relatively safe option to request an
 351                                 immediate reboot.</para></listitem>
 352                         </varlistentry>
 353
 354                         <varlistentry>
 355                                 <term><option>--root=</option></term>
 356
 357                                 <listitem><para>When used with
 358                                 <command>enable</command>/<command>disable</command>/<command>is-enabled</command> (and
 359                                 related commands), use alternative
 360                                 root path when looking for unit
 361                                 files.</para></listitem>
 362                         </varlistentry>
 363
 364                         <varlistentry>
 365                                 <term><option>--runtime</option></term>
 366
 367                                 <listitem><para>When used with
 368                                 <command>enable</command>/<command>disable</command>/<command>is-enabled</command> (and related commands), make
 369                                 changes only temporarily, so that they
 370                                 are dropped on the next reboot. This
 371                                 will have the effect that changes are
 372                                 not made in subdirectories of
 373                                 <filename>/etc</filename> but in
 374                                 <filename>/run</filename>, with
 375                                 identical immediate effects, however,
 376                                 since the latter is lost on reboot,
 377                                 the changes are lost
 378                                 too.</para></listitem>
 379                         </varlistentry>
 380
 381                         <varlistentry>
 382                                 <term><option>-H</option></term>
 383                                 <term><option>--host</option></term>
 384
 385                                 <listitem><para>Execute operation
 386                                 remotely. Specify a hostname, or
 387                                 username and hostname separated by @,
 388                                 to connect to. This will use SSH to
 389                                 talk to the remote systemd
 390                                 instance.</para></listitem>
 391                         </varlistentry>
 392
 393                         <varlistentry>
 394                                 <term><option>-P</option></term>
 395                                 <term><option>--privileged</option></term>
 396
 397                                 <listitem><para>Acquire privileges via
 398                                 PolicyKit before executing the
 399                                 operation.</para></listitem>
 400                         </varlistentry>
 401                 </variablelist>
 402
 403                 <para>The following commands are understood:</para>
 404
 405                 <variablelist>
 406                         <varlistentry>
 407                                 <term><command>list-units</command></term>
 408
 409                                 <listitem><para>List known units.</para></listitem>
 410                         </varlistentry>
 411                         <varlistentry>
 412                                 <term><command>start [NAME...]</command></term>
 413
 414                                 <listitem><para>Start (activate) one
 415                                 or more units specified on the command
 416                                 line.</para></listitem>
 417                         </varlistentry>
 418                         <varlistentry>
 419                                 <term><command>stop [NAME...]</command></term>
 420
 421                                 <listitem><para>Stop (deactivate) one
 422                                 or more units specified on the command
 423                                 line.</para></listitem>
 424                         </varlistentry>
 425                         <varlistentry>
 426                                 <term><command>reload [NAME...]</command></term>
 427
 428                                 <listitem><para>Asks all units listed
 429                                 on the command line to reload their
 430                                 configuration. Note that this will
 431                                 reload the service-specific
 432                                 configuration, not the unit
 433                                 configuration file of systemd. If you
 434                                 want systemd to reload the
 435                                 configuration file of a unit use the
 436                                 <command>daemon-reload</command>
 437                                 command. In other words: for the
 438                                 example case of Apache, this will
 439                                 reload Apache's
 440                                 <filename>httpd.conf</filename> in the
 441                                 web server, not the
 442                                 <filename>apache.service</filename>
 443                                 systemd unit file. </para>
 444
 445                                 <para>This command should not be
 446                                 confused with the
 447                                 <command>daemon-reload</command> or
 448                                 <command>load</command>
 449                                 commands.</para></listitem>
 450
 451                         </varlistentry>
 452                         <varlistentry>
 453                                 <term><command>restart [NAME...]</command></term>
 454
 455                                 <listitem><para>Restart one or more
 456                                 units specified on the command
 457                                 line. If the units are not running yet
 458                                 they will be
 459                                 started.</para></listitem>
 460                         </varlistentry>
 461                         <varlistentry>
 462                                 <term><command>try-restart [NAME...]</command></term>
 463
 464                                 <listitem><para>Restart one or more
 465                                 units specified on the command
 466                                 line if the units are running. Do
 467                                 nothing if units are not running.
 468                                 Note that for compatibility
 469                                 with Red Hat init scripts
 470                                 <command>condrestart</command> is
 471                                 equivalent to this command.</para></listitem>
 472                         </varlistentry>
 473                         <varlistentry>
 474                                 <term><command>reload-or-restart [NAME...]</command></term>
 475
 476                                 <listitem><para>Reload one or more
 477                                 units if they support it. If not,
 478                                 restart them instead. If the units
 479                                 are not running yet they will be
 480                                 started.</para></listitem>
 481                         </varlistentry>
 482                         <varlistentry>
 483                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 484
 485                                 <listitem><para>Reload one or more
 486                                 units if they support it. If not,
 487                                 restart them instead. Do nothing if
 488                                 the units are not running. Note that
 489                                 for compatibility with SysV init
 490                                 scripts
 491                                 <command>force-reload</command> is
 492                                 equivalent to this
 493                                 command.</para></listitem>
 494                         </varlistentry>
 495                         <varlistentry>
 496                                 <term><command>isolate [NAME]</command></term>
 497
 498                                 <listitem><para>Start the unit
 499                                 specified on the command line and its
 500                                 dependencies and stop all others.</para>
 501
 502                                 <para>This is similar to changing the
 503                                 runlevel in a traditional init system. The
 504                                 <command>isolate</command> command will
 505                                 immediately stop processes that are not
 506                                 enabled in the new unit, possibly including
 507                                 the graphical environment or terminal you
 508                                 are currently using.</para>
 509
 510                                 <para>Note that this works only on units
 511                                 where <option>AllowIsolate=</option> is
 512                                 enabled. See
 513                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 514                                 for details.</para></listitem>
 515                         </varlistentry>
 516                         <varlistentry>
 517                                 <term><command>kill [NAME...]</command></term>
 518
 519                                 <listitem><para>Send a signal to one
 520                                 or more processes of the unit. Use
 521                                 <option>--kill-who=</option> to select
 522                                 which process to kill. Use
 523                                 <option>--kill-mode=</option> to
 524                                 select the kill mode and
 525                                 <option>--signal=</option> to select
 526                                 the signal to send.</para></listitem>
 527                         </varlistentry>
 528                         <varlistentry>
 529                                 <term><command>is-active [NAME...]</command></term>
 530
 531                                 <listitem><para>Check whether any of
 532                                 the specified units are active
 533                                 (i.e. running). Returns an exit code
 534                                 0 if at least one is active, non-zero
 535                                 otherwise. Unless
 536                                 <option>--quiet</option> is specified
 537                                 this will also print the current unit
 538                                 state to STDOUT.</para></listitem>
 539                         </varlistentry>
 540                         <varlistentry>
 541                                 <term><command>status [NAME...|PID...]</command></term>
 542
 543                                 <listitem><para>Show terse runtime
 544                                 status information about one or more
 545                                 units. This function is intended to
 546                                 generate human-readable output. If you
 547                                 are looking for computer-parsable
 548                                 output, use <command>show</command>
 549                                 instead. If a PID is passed
 550                                 information about the unit the process
 551                                 of the PID belongs to is
 552                                 shown.</para></listitem>
 553                         </varlistentry>
 554                         <varlistentry>
 555                                 <term><command>show [NAME...|JOB...]</command></term>
 556
 557                                 <listitem><para>Show properties of one
 558                                 or more units, jobs or the manager
 559                                 itself. If no argument is specified
 560                                 properties of the manager will be
 561                                 shown. If a unit name is specified
 562                                 properties of the unit is shown, and
 563                                 if a job id is specified properties of
 564                                 the job is shown. By default, empty
 565                                 properties are suppressed. Use
 566                                 <option>--all</option> to show those
 567                                 too. To select specific properties to
 568                                 show use
 569                                 <option>--property=</option>. This
 570                                 command is intended to be used
 571                                 whenever computer-parsable output is
 572                                 required. Use
 573                                 <command>status</command> if you are
 574                                 looking for formatted human-readable
 575                                 output.</para></listitem>
 576                         </varlistentry>
 577
 578                         <varlistentry>
 579                                 <term><command>reset-failed [NAME...]</command></term>
 580
 581                                 <listitem><para>Reset the
 582                                 '<literal>failed</literal>' state of the
 583                                 specified units, or if no unit name is
 584                                 passed of all units. When a unit fails
 585                                 in some way (i.e. process exiting with
 586                                 non-zero error code, terminating
 587                                 abnormally or timing out) it will
 588                                 automatically enter the
 589                                 '<literal>failed</literal>' state and
 590                                 its exit code and status is recorded
 591                                 for introspection by the administrator
 592                                 until the service is restarted or
 593                                 reset with this
 594                                 command.</para></listitem>
 595                         </varlistentry>
 596
 597                         <varlistentry>
 598                                 <term><command>enable [NAME...]</command></term>
 599
 600                                 <listitem><para>Enable one or more
 601                                 unit files, as specified on the
 602                                 command line. This will create a
 603                                 number of symlinks as encoded in the
 604                                 <literal>[Install]</literal> sections
 605                                 of the unit files. After the symlinks
 606                                 have been created the systemd
 607                                 configuration is reloaded (in a way
 608                                 that is equivalent to
 609                                 <command>daemon-reload</command>) to
 610                                 ensure the changes are taken into
 611                                 account immediately. Note that this
 612                                 does not have the effect that any of
 613                                 the units enabled are also started at
 614                                 the same time. If this is desired a
 615                                 separate <command>start</command>
 616                                 command must be invoked for the
 617                                 unit.</para>
 618
 619                                 <para>This command will
 620                                 print the actions executed. This
 621                                 output may be suppressed by passing
 622                                 <option>--quiet</option>.</para>
 623
 624                                 <para>Note that this operation creates
 625                                 only the suggested symlinks for the
 626                                 units. While this command is the
 627                                 recommended way to manipulate the unit
 628                                 configuration directory, the
 629                                 administrator is free to make
 630                                 additional changes manually, by
 631                                 placing or removing symlinks in the
 632                                 directory. This is particularly useful
 633                                 to create configurations that deviate
 634                                 from the suggested default
 635                                 installation. In this case the
 636                                 administrator must make sure to invoke
 637                                 <command>daemon-reload</command>
 638                                 manually as necessary, to ensure his
 639                                 changes are taken into account.</para>
 640
 641                                 <para>Enabling units should not be
 642                                 confused with starting (activating)
 643                                 units, as done by the
 644                                 <command>start</command>
 645                                 command. Enabling and starting units
 646                                 is orthogonal: units may be enabled
 647                                 without being started and started
 648                                 without being enabled. Enabling simply
 649                                 hooks the unit into various suggested
 650                                 places (for example, so that the unit
 651                                 is automatically started on boot or
 652                                 when a particular kind of hardware is
 653                                 plugged in). Starting actually spawns
 654                                 the daemon process (in case of service
 655                                 units), or binds the socket (in case
 656                                 of socket units), and so
 657                                 on.</para>
 658
 659                                 <para>Depending on whether
 660                                 <option>--system</option>,
 661                                 <option>--user</option> or
 662                                 <option>--global</option> is specified
 663                                 this enables the unit for the system,
 664                                 for the calling user only
 665                                 or for all future logins of all
 666                                 users. Note that in the latter case no
 667                                 systemd daemon configuration is
 668                                 reloaded.</para>
 669                                 </listitem>
 670                         </varlistentry>
 671
 672                         <varlistentry>
 673                                 <term><command>disable [NAME...]</command></term>
 674
 675                                 <listitem><para>Disables one or more
 676                                 units. This removes all symlinks to
 677                                 the specified unit files from the unit
 678                                 configuration directory, and hence
 679                                 undoes the changes made by
 680                                 <command>enable</command>. Note
 681                                 however that this removes
 682                                 all symlinks to the unit files
 683                                 (i.e. including manual additions), not
 684                                 just those actually created by
 685                                 <command>enable</command>. This call
 686                                 implicitly reloads the systemd daemon
 687                                 configuration after completing the
 688                                 disabling of the units. Note that this
 689                                 command does not implicitly stop the
 690                                 units that is being disabled. If this
 691                                 is desired an additional
 692                                 <command>stop</command>command should
 693                                 be executed afterwards.</para>
 694
 695                                 <para>This command will print the
 696                                 actions executed. This output may be
 697                                 suppressed by passing
 698                                 <option>--quiet</option>.</para>
 699                                 </listitem>
 700
 701                                 <para>This command honors
 702                                 <option>--system</option>,
 703                                 <option>--user</option>,
 704                                 <option>--global</option> in a similar
 705                                 way as
 706                                 <command>enable</command>.</para>
 707                         </varlistentry>
 708
 709                         <varlistentry>
 710                                 <term><command>is-enabled [NAME...]</command></term>
 711
 712                                 <listitem><para>Checks whether any of
 713                                 the specified unit files is enabled
 714                                 (as with
 715                                 <command>enable</command>). Returns an
 716                                 exit code of 0 if at least one is
 717                                 enabled, non-zero otherwise. Prints
 718                                 the current enable status. To suppress
 719                                 this output use
 720                                 <option>--quiet</option>.</para></listitem>
 721                         </varlistentry>
 722
 723                         <varlistentry>
 724                                 <term><command>reenable [NAME...]</command></term>
 725
 726                                 <listitem><para>Reenable one or more
 727                                 unit files, as specified on the
 728                                 command line. This is a combination of
 729                                 <command>disable</command> and
 730                                 <command>enable</command> and is
 731                                 useful to reset the symlinks a unit is
 732                                 enabled with to the defaults
 733                                 configured in the
 734                                 <literal>[Install]</literal> section
 735                                 of the unit file.</para>
 736                                 </listitem>
 737                         </varlistentry>
 738
 739                         <varlistentry>
 740                                 <term><command>preset [NAME...]</command></term>
 741
 742                                 <listitem><para>Reset one or more unit
 743                                 files, as specified on the command
 744                                 line, to the defaults configured in a
 745                                 preset file. This has the same effect
 746                                 as <command>disable</command> or
 747                                 <command>enable</command>, depending
 748                                 how the unit is listed in the preset
 749                                 files.</para>
 750                                 </listitem>
 751                         </varlistentry>
 752
 753                         <varlistentry>
 754                                 <term><command>mask [NAME...]</command></term>
 755
 756                                 <listitem><para>Mask one or more unit
 757                                 files, as specified on the command
 758                                 line. This will link these units to
 759                                 <filename>/dev/null</filename>, making
 760                                 it impossible to start them. This is a stronger version
 761                                 of <command>disable</command>, since
 762                                 it prohibits all kinds of activation
 763                                 of the unit, including manual
 764                                 activation. Use this option with
 765                                 care.</para>
 766                                 </listitem>
 767                         </varlistentry>
 768
 769                         <varlistentry>
 770                                 <term><command>unmask [NAME...]</command></term>
 771
 772                                 <listitem><para>Unmask one or more
 773                                 unit files, as specified on the
 774                                 command line. This will undo the
 775                                 effect of
 776                                 <command>mask</command>.</para>
 777                                 </listitem>
 778                         </varlistentry>
 779
 780                         <varlistentry>
 781                                 <term><command>link [NAME...]</command></term>
 782
 783                                 <listitem><para>Link a unit file that
 784                                 is not in the unit file search paths
 785                                 into the unit file search path. This
 786                                 requires an absolute path to a unit
 787                                 file. The effect of this can be undone
 788                                 with <command>disable</command>. The
 789                                 effect of this command is that a unit
 790                                 file is available for
 791                                 <command>start</command> and other
 792                                 commands although it isn't installed
 793                                 directly in the unit search
 794                                 path.</para>
 795                                 </listitem>
 796                         </varlistentry>
 797
 798                         <varlistentry>
 799                                 <term><command>load [NAME...]</command></term>
 800
 801                                 <listitem><para>Load one or more units
 802                                 specified on the command line. This
 803                                 will simply load their configuration
 804                                 from disk, but not start them. To
 805                                 start them you need to use the
 806                                 <command>start</command> command which
 807                                 will implicitly load a unit that has
 808                                 not been loaded yet. Note that systemd
 809                                 garbage collects loaded units that are
 810                                 not active or referenced by an active
 811                                 unit. This means that units loaded
 812                                 this way will usually not stay loaded
 813                                 for long. Also note that this command
 814                                 cannot be used to reload unit
 815                                 configuration. Use the
 816                                 <command>daemon-reload</command>
 817                                 command for that. All in all, this
 818                                 command is of little use except for
 819                                 debugging.</para>
 820                                 <para>This command should not be
 821                                 confused with the
 822                                 <command>daemon-reload</command> or
 823                                 <command>reload</command>
 824                                 commands.</para></listitem>
 825                         </varlistentry>
 826                         <varlistentry>
 827                                 <term><command>list-jobs</command></term>
 828
 829                                 <listitem><para>List jobs that are in progress.</para></listitem>
 830                         </varlistentry>
 831                         <varlistentry>
 832                                 <term><command>cancel [JOB...]</command></term>
 833
 834                                 <listitem><para>Cancel one or more
 835                                 jobs specified on the command line by
 836                                 their numeric job
 837                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 838                         </varlistentry>
 839                         <varlistentry>
 840                                 <term><command>dump</command></term>
 841
 842                                 <listitem><para>Dump server
 843                                 status. This will output a (usually
 844                                 very long) human readable manager
 845                                 status dump. Its format is subject to
 846                                 change without notice and should not
 847                                 be parsed by
 848                                 applications.</para></listitem>
 849                         </varlistentry>
 850                         <varlistentry>
 851                                 <term><command>dot</command></term>
 852
 853                                 <listitem><para>Generate textual
 854                                 dependency graph description in dot
 855                                 format for further processing with the
 856                                 GraphViz
 857                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 858                                 tool. Use a command line like
 859                                 <command>systemctl dot | dot -Tsvg >
 860                                 systemd.svg</command> to generate a
 861                                 graphical dependency tree. Unless
 862                                 <option>--order</option> or
 863                                 <option>--require</option> is passed
 864                                 the generated graph will show both
 865                                 ordering and requirement
 866                                 dependencies.</para></listitem>
 867                         </varlistentry>
 868                         <varlistentry>
 869                                 <term><command>snapshot [NAME]</command></term>
 870
 871                                 <listitem><para>Create a snapshot. If
 872                                 a snapshot name is specified, the new
 873                                 snapshot will be named after it. If
 874                                 none is specified an automatic
 875                                 snapshot name is generated. In either
 876                                 case, the snapshot name used is
 877                                 printed to STDOUT, unless
 878                                 <option>--quiet</option> is
 879                                 specified.</para>
 880
 881                                 <para>A snapshot refers to a saved
 882                                 state of the systemd manager. It is
 883                                 implemented itself as a unit that is
 884                                 generated dynamically with this
 885                                 command and has dependencies on all
 886                                 units active at the time. At a later
 887                                 time the user may return to this state
 888                                 by using the
 889                                 <command>isolate</command> command on
 890                                 the snapshot unit.</para></listitem>
 891
 892                                 <para>Snapshots are only useful for
 893                                 saving and restoring which units are
 894                                 running or are stopped, they do not
 895                                 save/restore any other
 896                                 state. Snapshots are dynamic and lost
 897                                 on reboot.</para>
 898                         </varlistentry>
 899                         <varlistentry>
 900                                 <term><command>delete [NAME...]</command></term>
 901
 902                                 <listitem><para>Remove a snapshot
 903                                 previously created with
 904                                 <command>snapshot</command>.</para></listitem>
 905                         </varlistentry>
 906                         <varlistentry>
 907                                 <term><command>daemon-reload</command></term>
 908
 909                                 <listitem><para>Reload systemd manager
 910                                 configuration. This will reload all
 911                                 unit files and recreate the entire
 912                                 dependency tree. While the daemon is
 913                                 reloaded, all sockets systemd listens
 914                                 on on behalf of user configuration will
 915                                 stay accessible.</para> <para>This
 916                                 command should not be confused with
 917                                 the <command>load</command> or
 918                                 <command>reload</command>
 919                                 commands.</para></listitem>
 920                         </varlistentry>
 921                         <varlistentry>
 922                                 <term><command>daemon-reexec</command></term>
 923
 924                                 <listitem><para>Reexecute the systemd
 925                                 manager. This will serialize the
 926                                 manager state, reexecute the process
 927                                 and deserialize the state again. This
 928                                 command is of little use except for
 929                                 debugging and package
 930                                 upgrades. Sometimes it might be
 931                                 helpful as a heavy-weight
 932                                 <command>daemon-reload</command>. While
 933                                 the daemon is reexecuted all sockets
 934                                 systemd listens on on behalf of user
 935                                 configuration will stay
 936                                 accessible.</para></listitem>
 937                         </varlistentry>
 938                         <varlistentry>
 939                                 <term><command>show-environment</command></term>
 940
 941                                 <listitem><para>Dump the systemd
 942                                 manager environment block. The
 943                                 environment block will be dumped in
 944                                 straight-forward form suitable for
 945                                 sourcing into a shell script. This
 946                                 environment block will be passed to
 947                                 all processes the manager
 948                                 spawns.</para></listitem>
 949                         </varlistentry>
 950                         <varlistentry>
 951                                 <term><command>set-environment [NAME=VALUE...]</command></term>
 952
 953                                 <listitem><para>Set one or more
 954                                 systemd manager environment variables,
 955                                 as specified on the command
 956                                 line.</para></listitem>
 957                         </varlistentry>
 958                         <varlistentry>
 959                                 <term><command>unset-environment [NAME...]</command></term>
 960
 961                                 <listitem><para>Unset one or more
 962                                 systemd manager environment
 963                                 variables. If only a variable name is
 964                                 specified it will be removed
 965                                 regardless of its value. If a variable
 966                                 and a value are specified the variable
 967                                 is only removed if it has the
 968                                 specified value.</para></listitem>
 969                         </varlistentry>
 970                         <varlistentry>
 971                                 <term><command>default</command></term>
 972
 973                                 <listitem><para>Enter default
 974                                 mode. This is mostly equivalent to
 975                                 <command>start
 976                                 default.target</command>.</para></listitem>
 977                         </varlistentry>
 978                         <varlistentry>
 979                                 <term><command>rescue</command></term>
 980
 981                                 <listitem><para>Enter rescue
 982                                 mode. This is mostly equivalent to
 983                                 <command>isolate
 984                                 rescue.target</command> but also
 985                                 prints a wall message to all
 986                                 users.</para></listitem>
 987                         </varlistentry>
 988                         <varlistentry>
 989                                 <term><command>emergency</command></term>
 990
 991                                 <listitem><para>Enter emergency
 992                                 mode. This is mostly equivalent to
 993                                 <command>isolate
 994                                 emergency.target</command> but also
 995                                 prints a wall message to all
 996                                 users.</para></listitem>
 997                         </varlistentry>
 998                         <varlistentry>
 999                                 <term><command>halt</command></term>
1000
1001                                 <listitem><para>Shut down and halt the
1002                                 system. This is mostly equivalent to
1003                                 <command>start halt.target</command>
1004                                 but also prints a wall message to all
1005                                 users.  If
1006                                 combined with <option>--force</option>
1007                                 shutdown of all running services is
1008                                 skipped, however all processes are killed
1009                                 and all file systems are unmounted or
1010                                 mounted read-only, immediately
1011                                 followed by the
1012                                 system halt.</para></listitem>
1013                         </varlistentry>
1014                         <varlistentry>
1015                                 <term><command>poweroff</command></term>
1016
1017                                 <listitem><para>Shut down and
1018                                 power-off the system. This is mostly
1019                                 equivalent to <command>start
1020                                 poweroff.target</command> but also
1021                                 prints a wall message to all
1022                                 users. If
1023                                 combined with <option>--force</option>
1024                                 shutdown of all running services is
1025                                 skipped, however all processes are killed
1026                                 and all file systems are unmounted or
1027                                 mounted read-only, immediately
1028                                 followed by the
1029                                 powering off.</para></listitem>
1030                         </varlistentry>
1031                         <varlistentry>
1032                                 <term><command>reboot</command></term>
1033
1034                                 <listitem><para>Shut down and
1035                                 reboot the system. This is mostly
1036                                 equivalent to <command>start
1037                                 reboot.target</command> but also
1038                                 prints a wall message to all
1039                                 users. If
1040                                 combined with <option>--force</option>
1041                                 shutdown of all running services is
1042                                 skipped, however all processes are killed
1043                                 and all file systems are unmounted or
1044                                 mounted read-only, immediately
1045                                 followed by the
1046                                 reboot.</para></listitem>
1047                         </varlistentry>
1048                         <varlistentry>
1049                                 <term><command>kexec</command></term>
1050
1051                                 <listitem><para>Shut down and reboot
1052                                 the system via kexec. This is mostly
1053                                 equivalent to <command>start
1054                                 kexec.target</command> but also prints
1055                                 a wall message to all users. If
1056                                 combined with <option>--force</option>
1057                                 shutdown of all running services is
1058                                 skipped, however all processes are killed
1059                                 and all file systems are unmounted or
1060                                 mounted read-only, immediately
1061                                 followed by the
1062                                 reboot.</para></listitem>
1063                         </varlistentry>
1064                         <varlistentry>
1065                                 <term><command>exit</command></term>
1066
1067                                 <listitem><para>Ask the systemd
1068                                 manager to quit. This is only
1069                                 supported for user service managers
1070                                 (i.e. in conjunction with the
1071                                 <option>--user</option> option) and
1072                                 will fail otherwise.</para></listitem>
1073                         </varlistentry>
1074                 </variablelist>
1075
1076         </refsect1>
1077
1078         <refsect1>
1079                 <title>Exit status</title>
1080
1081                 <para>On success 0 is returned, a non-zero failure
1082                 code otherwise.</para>
1083         </refsect1>
1084
1085         <refsect1>
1086                 <title>Environment</title>
1087
1088                 <variablelist>
1089                         <varlistentry>
1090                                 <term><varname>$SYSTEMD_PAGER</varname></term>
1091                                 <listitem><para>Pager to use when
1092                                 <option>--no-pager</option> is not given;
1093                                 overrides <varname>$PAGER</varname>.  Setting
1094                                 this to an empty string or the value
1095                                 <literal>cat</literal> is equivalent to passing
1096                                 <option>--no-pager</option>.</para></listitem>
1097                         </varlistentry>
1098                 </variablelist>
1099         </refsect1>
1100
1101         <refsect1>
1102                 <title>See Also</title>
1103                 <para>
1104                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1105                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1106                         <citerefentry><refentrytitle>systemd-loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1107                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1108                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1109                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
1110                 </para>
1111         </refsect1>
1112
1113 </refentry>