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
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  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-legend</option></term>
 202
 203                                 <listitem><para>Do not print a legend, i.e.
 204                                 the column headers and the footer with hints.
 205                                 </para></listitem>
 206                         </varlistentry>
 207
 208                         <varlistentry>
 209                                 <term><option>--no-pager</option></term>
 210
 211                                 <listitem><para>Do not pipe output into a
 212                                 pager.</para></listitem>
 213                         </varlistentry>
 214
 215                         <varlistentry>
 216                                 <term><option>--system</option></term>
 217
 218                                 <listitem><para>Talk to the systemd
 219                                 system manager. (Default)</para></listitem>
 220                         </varlistentry>
 221
 222                         <varlistentry>
 223                                 <term><option>--user</option></term>
 224
 225                                 <listitem><para>Talk to the systemd
 226                                 manager of the calling user.</para></listitem>
 227                         </varlistentry>
 228
 229                         <varlistentry>
 230                                 <term><option>--order</option></term>
 231                                 <term><option>--require</option></term>
 232
 233                                 <listitem><para>When used in
 234                                 conjunction with the
 235                                 <command>dot</command> command (see
 236                                 below), selects which dependencies are
 237                                 shown in the dependency graph. If
 238                                 <option>--order</option> is passed
 239                                 only dependencies of type
 240                                 <varname>After=</varname> or
 241                                 <varname>Before=</varname> are
 242                                 shown. If <option>--require</option>
 243                                 is passed only dependencies of type
 244                                 <varname>Requires=</varname>,
 245                                 <varname>RequiresOverridable=</varname>,
 246                                 <varname>Requisite=</varname>,
 247                                 <varname>RequisiteOverridable=</varname>,
 248                                 <varname>Wants=</varname> and
 249                                 <varname>Conflicts=</varname> are
 250                                 shown. If neither is passed, shows
 251                                 dependencies of all these
 252                                 types.</para></listitem>
 253                         </varlistentry>
 254
 255                         <varlistentry>
 256                                 <term><option>--no-wall</option></term>
 257
 258                                 <listitem><para>Don't send wall
 259                                 message before
 260                                 halt, power-off, reboot.</para></listitem>
 261                         </varlistentry>
 262
 263                         <varlistentry>
 264                                 <term><option>--global</option></term>
 265
 266                                 <listitem><para>When used with
 267                                 <command>enable</command> and
 268                                 <command>disable</command>, operate on the
 269                                 global user configuration
 270                                 directory, thus enabling or disabling
 271                                 a unit file globally for all future
 272                                 logins of all users.</para></listitem>
 273                         </varlistentry>
 274
 275                         <varlistentry>
 276                                 <term><option>--no-reload</option></term>
 277
 278                                 <listitem><para>When used with
 279                                 <command>enable</command> and
 280                                 <command>disable</command>, do not
 281                                 implicitly reload daemon configuration
 282                                 after executing the
 283                                 changes.</para></listitem>
 284                         </varlistentry>
 285
 286                         <varlistentry>
 287                                 <term><option>--no-ask-password</option></term>
 288
 289                                 <listitem><para>When used with
 290                                 <command>start</command> and related
 291                                 commands, disables asking for
 292                                 passwords. Background services may
 293                                 require input of a password or
 294                                 passphrase string, for example to
 295                                 unlock system hard disks or
 296                                 cryptographic certificates. Unless
 297                                 this option is specified and the
 298                                 command is invoked from a terminal
 299                                 <command>systemctl</command> will
 300                                 query the user on the terminal for the
 301                                 necessary secrets. Use this option to
 302                                 switch this behavior off. In this
 303                                 case the password must be supplied by
 304                                 some other means (for example
 305                                 graphical password agents) or the
 306                                 service might fail.</para></listitem>
 307                         </varlistentry>
 308
 309                         <varlistentry>
 310                                 <term><option>--kill-who=</option></term>
 311
 312                                 <listitem><para>When used with
 313                                 <command>kill</command>, choose which
 314                                 processes to kill. Must be one of
 315                                 <option>main</option>,
 316                                 <option>control</option> or
 317                                 <option>all</option> to select whether
 318                                 to kill only the main process of the
 319                                 unit, the control process or all
 320                                 processes of the unit. If omitted
 321                                 defaults to
 322                                 <option>all</option>.</para></listitem>
 323                         </varlistentry>
 324
 325                         <varlistentry>
 326                                 <term><option>--signal=</option></term>
 327                                 <term><option>-s</option></term>
 328
 329                                 <listitem><para>When used with
 330                                 <command>kill</command>, choose which
 331                                 signal to send to selected
 332                                 processes. Must be one of the well
 333                                 known signal specifiers such as
 334                                 SIGTERM, SIGINT or SIGSTOP. If
 335                                 omitted defaults to
 336                                 <option>SIGTERM</option>.</para></listitem>
 337                         </varlistentry>
 338
 339                         <varlistentry>
 340                                 <term><option>--force</option></term>
 341                                 <term><option>-f</option></term>
 342
 343                                 <listitem><para>When used with
 344                                 <command>enable</command>, override any
 345                                 existing conflicting
 346                                 symlinks.</para></listitem>
 347
 348                                 <listitem><para>When used with
 349                                 <command>halt</command>,
 350                                 <command>poweroff</command>,
 351                                 <command>reboot</command> or
 352                                 <command>kexec</command> execute
 353                                 selected operation without shutting
 354                                 down all units. However, all processes
 355                                 will be killed forcibly and all file
 356                                 systems are unmounted or remounted
 357                                 read-only. This is hence a drastic but
 358                                 relatively safe option to request an
 359                                 immediate reboot.</para></listitem>
 360                         </varlistentry>
 361
 362                         <varlistentry>
 363                                 <term><option>--root=</option></term>
 364
 365                                 <listitem><para>When used with
 366                                 <command>enable</command>/<command>disable</command>/<command>is-enabled</command> (and
 367                                 related commands), use alternative
 368                                 root path when looking for unit
 369                                 files.</para></listitem>
 370                         </varlistentry>
 371
 372                         <varlistentry>
 373                                 <term><option>--runtime</option></term>
 374
 375                                 <listitem><para>When used with
 376                                 <command>enable</command>/<command>disable</command>/<command>is-enabled</command> (and related commands), make
 377                                 changes only temporarily, so that they
 378                                 are dropped on the next reboot. This
 379                                 will have the effect that changes are
 380                                 not made in subdirectories of
 381                                 <filename>/etc</filename> but in
 382                                 <filename>/run</filename>, with
 383                                 identical immediate effects, however,
 384                                 since the latter is lost on reboot,
 385                                 the changes are lost
 386                                 too.</para></listitem>
 387                         </varlistentry>
 388
 389                         <varlistentry>
 390                                 <term><option>-H</option></term>
 391                                 <term><option>--host</option></term>
 392
 393                                 <listitem><para>Execute operation
 394                                 remotely. Specify a hostname, or
 395                                 username and hostname separated by @,
 396                                 to connect to. This will use SSH to
 397                                 talk to the remote systemd
 398                                 instance.</para></listitem>
 399                         </varlistentry>
 400
 401                         <varlistentry>
 402                                 <term><option>-P</option></term>
 403                                 <term><option>--privileged</option></term>
 404
 405                                 <listitem><para>Acquire privileges via
 406                                 PolicyKit before executing the
 407                                 operation.</para></listitem>
 408                         </varlistentry>
 409                 </variablelist>
 410
 411                 <para>The following commands are understood:</para>
 412
 413                 <variablelist>
 414                         <varlistentry>
 415                                 <term><command>list-units</command></term>
 416
 417                                 <listitem><para>List known units.</para></listitem>
 418                         </varlistentry>
 419                         <varlistentry>
 420                                 <term><command>start [NAME...]</command></term>
 421
 422                                 <listitem><para>Start (activate) one
 423                                 or more units specified on the command
 424                                 line.</para></listitem>
 425                         </varlistentry>
 426                         <varlistentry>
 427                                 <term><command>stop [NAME...]</command></term>
 428
 429                                 <listitem><para>Stop (deactivate) one
 430                                 or more units specified on the command
 431                                 line.</para></listitem>
 432                         </varlistentry>
 433                         <varlistentry>
 434                                 <term><command>reload [NAME...]</command></term>
 435
 436                                 <listitem><para>Asks all units listed
 437                                 on the command line to reload their
 438                                 configuration. Note that this will
 439                                 reload the service-specific
 440                                 configuration, not the unit
 441                                 configuration file of systemd. If you
 442                                 want systemd to reload the
 443                                 configuration file of a unit use the
 444                                 <command>daemon-reload</command>
 445                                 command. In other words: for the
 446                                 example case of Apache, this will
 447                                 reload Apache's
 448                                 <filename>httpd.conf</filename> in the
 449                                 web server, not the
 450                                 <filename>apache.service</filename>
 451                                 systemd unit file. </para>
 452
 453                                 <para>This command should not be
 454                                 confused with the
 455                                 <command>daemon-reload</command> or
 456                                 <command>load</command>
 457                                 commands.</para></listitem>
 458
 459                         </varlistentry>
 460                         <varlistentry>
 461                                 <term><command>restart [NAME...]</command></term>
 462
 463                                 <listitem><para>Restart one or more
 464                                 units specified on the command
 465                                 line. If the units are not running yet
 466                                 they will be
 467                                 started.</para></listitem>
 468                         </varlistentry>
 469                         <varlistentry>
 470                                 <term><command>try-restart [NAME...]</command></term>
 471
 472                                 <listitem><para>Restart one or more
 473                                 units specified on the command
 474                                 line if the units are running. Do
 475                                 nothing if units are not running.
 476                                 Note that for compatibility
 477                                 with Red Hat init scripts
 478                                 <command>condrestart</command> is
 479                                 equivalent to this command.</para></listitem>
 480                         </varlistentry>
 481                         <varlistentry>
 482                                 <term><command>reload-or-restart [NAME...]</command></term>
 483
 484                                 <listitem><para>Reload one or more
 485                                 units if they support it. If not,
 486                                 restart them instead. If the units
 487                                 are not running yet they will be
 488                                 started.</para></listitem>
 489                         </varlistentry>
 490                         <varlistentry>
 491                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 492
 493                                 <listitem><para>Reload one or more
 494                                 units if they support it. If not,
 495                                 restart them instead. Do nothing if
 496                                 the units are not running. Note that
 497                                 for compatibility with SysV init
 498                                 scripts
 499                                 <command>force-reload</command> is
 500                                 equivalent to this
 501                                 command.</para></listitem>
 502                         </varlistentry>
 503                         <varlistentry>
 504                                 <term><command>isolate [NAME]</command></term>
 505
 506                                 <listitem><para>Start the unit
 507                                 specified on the command line and its
 508                                 dependencies and stop all others.</para>
 509
 510                                 <para>This is similar to changing the
 511                                 runlevel in a traditional init system. The
 512                                 <command>isolate</command> command will
 513                                 immediately stop processes that are not
 514                                 enabled in the new unit, possibly including
 515                                 the graphical environment or terminal you
 516                                 are currently using.</para>
 517
 518                                 <para>Note that this works only on units
 519                                 where <option>AllowIsolate=</option> is
 520                                 enabled. See
 521                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 522                                 for details.</para></listitem>
 523                         </varlistentry>
 524                         <varlistentry>
 525                                 <term><command>kill [NAME...]</command></term>
 526
 527                                 <listitem><para>Send a signal to one
 528                                 or more processes of the unit. Use
 529                                 <option>--kill-who=</option> to select
 530                                 which process to kill. Use
 531                                 <option>--kill-mode=</option> to
 532                                 select the kill mode and
 533                                 <option>--signal=</option> to select
 534                                 the signal to send.</para></listitem>
 535                         </varlistentry>
 536                         <varlistentry>
 537                                 <term><command>is-active [NAME...]</command></term>
 538
 539                                 <listitem><para>Check whether any of
 540                                 the specified units are active
 541                                 (i.e. running). Returns an exit code
 542                                 0 if at least one is active, non-zero
 543                                 otherwise. Unless
 544                                 <option>--quiet</option> is specified
 545                                 this will also print the current unit
 546                                 state to STDOUT.</para></listitem>
 547                         </varlistentry>
 548                         <varlistentry>
 549                                 <term><command>status [NAME...|PID...]</command></term>
 550
 551                                 <listitem><para>Show terse runtime
 552                                 status information about one or more
 553                                 units. This function is intended to
 554                                 generate human-readable output. If you
 555                                 are looking for computer-parsable
 556                                 output, use <command>show</command>
 557                                 instead. If a PID is passed
 558                                 information about the unit the process
 559                                 of the PID belongs to is
 560                                 shown.</para></listitem>
 561                         </varlistentry>
 562                         <varlistentry>
 563                                 <term><command>show [NAME...|JOB...]</command></term>
 564
 565                                 <listitem><para>Show properties of one
 566                                 or more units, jobs or the manager
 567                                 itself. If no argument is specified
 568                                 properties of the manager will be
 569                                 shown. If a unit name is specified
 570                                 properties of the unit is shown, and
 571                                 if a job id is specified properties of
 572                                 the job is shown. By default, empty
 573                                 properties are suppressed. Use
 574                                 <option>--all</option> to show those
 575                                 too. To select specific properties to
 576                                 show use
 577                                 <option>--property=</option>. This
 578                                 command is intended to be used
 579                                 whenever computer-parsable output is
 580                                 required. Use
 581                                 <command>status</command> if you are
 582                                 looking for formatted human-readable
 583                                 output.</para></listitem>
 584                         </varlistentry>
 585
 586                         <varlistentry>
 587                                 <term><command>reset-failed [NAME...]</command></term>
 588
 589                                 <listitem><para>Reset the
 590                                 '<literal>failed</literal>' state of the
 591                                 specified units, or if no unit name is
 592                                 passed of all units. When a unit fails
 593                                 in some way (i.e. process exiting with
 594                                 non-zero error code, terminating
 595                                 abnormally or timing out) it will
 596                                 automatically enter the
 597                                 '<literal>failed</literal>' state and
 598                                 its exit code and status is recorded
 599                                 for introspection by the administrator
 600                                 until the service is restarted or
 601                                 reset with this
 602                                 command.</para></listitem>
 603                         </varlistentry>
 604
 605                         <varlistentry>
 606                                 <term><command>list-unit-files</command></term>
 607
 608                                 <listitem><para>List installed unit files.
 609                                 </para></listitem>
 610                         </varlistentry>
 611
 612                         <varlistentry>
 613                                 <term><command>enable [NAME...]</command></term>
 614
 615                                 <listitem><para>Enable one or more
 616                                 unit files, as specified on the
 617                                 command line. This will create a
 618                                 number of symlinks as encoded in the
 619                                 <literal>[Install]</literal> sections
 620                                 of the unit files. After the symlinks
 621                                 have been created the systemd
 622                                 configuration is reloaded (in a way
 623                                 that is equivalent to
 624                                 <command>daemon-reload</command>) to
 625                                 ensure the changes are taken into
 626                                 account immediately. Note that this
 627                                 does not have the effect that any of
 628                                 the units enabled are also started at
 629                                 the same time. If this is desired a
 630                                 separate <command>start</command>
 631                                 command must be invoked for the
 632                                 unit.</para>
 633
 634                                 <para>This command will
 635                                 print the actions executed. This
 636                                 output may be suppressed by passing
 637                                 <option>--quiet</option>.</para>
 638
 639                                 <para>Note that this operation creates
 640                                 only the suggested symlinks for the
 641                                 units. While this command is the
 642                                 recommended way to manipulate the unit
 643                                 configuration directory, the
 644                                 administrator is free to make
 645                                 additional changes manually, by
 646                                 placing or removing symlinks in the
 647                                 directory. This is particularly useful
 648                                 to create configurations that deviate
 649                                 from the suggested default
 650                                 installation. In this case the
 651                                 administrator must make sure to invoke
 652                                 <command>daemon-reload</command>
 653                                 manually as necessary, to ensure his
 654                                 changes are taken into account.</para>
 655
 656                                 <para>Enabling units should not be
 657                                 confused with starting (activating)
 658                                 units, as done by the
 659                                 <command>start</command>
 660                                 command. Enabling and starting units
 661                                 is orthogonal: units may be enabled
 662                                 without being started and started
 663                                 without being enabled. Enabling simply
 664                                 hooks the unit into various suggested
 665                                 places (for example, so that the unit
 666                                 is automatically started on boot or
 667                                 when a particular kind of hardware is
 668                                 plugged in). Starting actually spawns
 669                                 the daemon process (in case of service
 670                                 units), or binds the socket (in case
 671                                 of socket units), and so
 672                                 on.</para>
 673
 674                                 <para>Depending on whether
 675                                 <option>--system</option>,
 676                                 <option>--user</option> or
 677                                 <option>--global</option> is specified
 678                                 this enables the unit for the system,
 679                                 for the calling user only
 680                                 or for all future logins of all
 681                                 users. Note that in the latter case no
 682                                 systemd daemon configuration is
 683                                 reloaded.</para>
 684                                 </listitem>
 685                         </varlistentry>
 686
 687                         <varlistentry>
 688                                 <term><command>disable [NAME...]</command></term>
 689
 690                                 <listitem><para>Disables one or more
 691                                 units. This removes all symlinks to
 692                                 the specified unit files from the unit
 693                                 configuration directory, and hence
 694                                 undoes the changes made by
 695                                 <command>enable</command>. Note
 696                                 however that this removes
 697                                 all symlinks to the unit files
 698                                 (i.e. including manual additions), not
 699                                 just those actually created by
 700                                 <command>enable</command>. This call
 701                                 implicitly reloads the systemd daemon
 702                                 configuration after completing the
 703                                 disabling of the units. Note that this
 704                                 command does not implicitly stop the
 705                                 units that is being disabled. If this
 706                                 is desired an additional
 707                                 <command>stop</command>command should
 708                                 be executed afterwards.</para>
 709
 710                                 <para>This command will print the
 711                                 actions executed. This output may be
 712                                 suppressed by passing
 713                                 <option>--quiet</option>.</para>
 714                                 </listitem>
 715
 716                                 <para>This command honors
 717                                 <option>--system</option>,
 718                                 <option>--user</option>,
 719                                 <option>--global</option> in a similar
 720                                 way as
 721                                 <command>enable</command>.</para>
 722                         </varlistentry>
 723
 724                         <varlistentry>
 725                                 <term><command>is-enabled [NAME...]</command></term>
 726
 727                                 <listitem><para>Checks whether any of
 728                                 the specified unit files is enabled
 729                                 (as with
 730                                 <command>enable</command>). Returns an
 731                                 exit code of 0 if at least one is
 732                                 enabled, non-zero otherwise. Prints
 733                                 the current enable status. To suppress
 734                                 this output use
 735                                 <option>--quiet</option>.</para></listitem>
 736                         </varlistentry>
 737
 738                         <varlistentry>
 739                                 <term><command>reenable [NAME...]</command></term>
 740
 741                                 <listitem><para>Reenable one or more
 742                                 unit files, as specified on the
 743                                 command line. This is a combination of
 744                                 <command>disable</command> and
 745                                 <command>enable</command> and is
 746                                 useful to reset the symlinks a unit is
 747                                 enabled with to the defaults
 748                                 configured in the
 749                                 <literal>[Install]</literal> section
 750                                 of the unit file.</para>
 751                                 </listitem>
 752                         </varlistentry>
 753
 754                         <varlistentry>
 755                                 <term><command>preset [NAME...]</command></term>
 756
 757                                 <listitem><para>Reset one or more unit
 758                                 files, as specified on the command
 759                                 line, to the defaults configured in a
 760                                 preset file. This has the same effect
 761                                 as <command>disable</command> or
 762                                 <command>enable</command>, depending
 763                                 how the unit is listed in the preset
 764                                 files.</para>
 765                                 </listitem>
 766                         </varlistentry>
 767
 768                         <varlistentry>
 769                                 <term><command>mask [NAME...]</command></term>
 770
 771                                 <listitem><para>Mask one or more unit
 772                                 files, as specified on the command
 773                                 line. This will link these units to
 774                                 <filename>/dev/null</filename>, making
 775                                 it impossible to start them. This is a stronger version
 776                                 of <command>disable</command>, since
 777                                 it prohibits all kinds of activation
 778                                 of the unit, including manual
 779                                 activation. Use this option with
 780                                 care.</para>
 781                                 </listitem>
 782                         </varlistentry>
 783
 784                         <varlistentry>
 785                                 <term><command>unmask [NAME...]</command></term>
 786
 787                                 <listitem><para>Unmask one or more
 788                                 unit files, as specified on the
 789                                 command line. This will undo the
 790                                 effect of
 791                                 <command>mask</command>.</para>
 792                                 </listitem>
 793                         </varlistentry>
 794
 795                         <varlistentry>
 796                                 <term><command>link [NAME...]</command></term>
 797
 798                                 <listitem><para>Link a unit file that
 799                                 is not in the unit file search paths
 800                                 into the unit file search path. This
 801                                 requires an absolute path to a unit
 802                                 file. The effect of this can be undone
 803                                 with <command>disable</command>. The
 804                                 effect of this command is that a unit
 805                                 file is available for
 806                                 <command>start</command> and other
 807                                 commands although it isn't installed
 808                                 directly in the unit search
 809                                 path.</para>
 810                                 </listitem>
 811                         </varlistentry>
 812
 813                         <varlistentry>
 814                                 <term><command>load [NAME...]</command></term>
 815
 816                                 <listitem><para>Load one or more units
 817                                 specified on the command line. This
 818                                 will simply load their configuration
 819                                 from disk, but not start them. To
 820                                 start them you need to use the
 821                                 <command>start</command> command which
 822                                 will implicitly load a unit that has
 823                                 not been loaded yet. Note that systemd
 824                                 garbage collects loaded units that are
 825                                 not active or referenced by an active
 826                                 unit. This means that units loaded
 827                                 this way will usually not stay loaded
 828                                 for long. Also note that this command
 829                                 cannot be used to reload unit
 830                                 configuration. Use the
 831                                 <command>daemon-reload</command>
 832                                 command for that. All in all, this
 833                                 command is of little use except for
 834                                 debugging.</para>
 835                                 <para>This command should not be
 836                                 confused with the
 837                                 <command>daemon-reload</command> or
 838                                 <command>reload</command>
 839                                 commands.</para></listitem>
 840                         </varlistentry>
 841                         <varlistentry>
 842                                 <term><command>list-jobs</command></term>
 843
 844                                 <listitem><para>List jobs that are in progress.</para></listitem>
 845                         </varlistentry>
 846                         <varlistentry>
 847                                 <term><command>cancel [JOB...]</command></term>
 848
 849                                 <listitem><para>Cancel one or more
 850                                 jobs specified on the command line by
 851                                 their numeric job
 852                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 853                         </varlistentry>
 854                         <varlistentry>
 855                                 <term><command>dump</command></term>
 856
 857                                 <listitem><para>Dump server
 858                                 status. This will output a (usually
 859                                 very long) human readable manager
 860                                 status dump. Its format is subject to
 861                                 change without notice and should not
 862                                 be parsed by
 863                                 applications.</para></listitem>
 864                         </varlistentry>
 865                         <varlistentry>
 866                                 <term><command>dot</command></term>
 867
 868                                 <listitem><para>Generate textual
 869                                 dependency graph description in dot
 870                                 format for further processing with the
 871                                 GraphViz
 872                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 873                                 tool. Use a command line like
 874                                 <command>systemctl dot | dot -Tsvg >
 875                                 systemd.svg</command> to generate a
 876                                 graphical dependency tree. Unless
 877                                 <option>--order</option> or
 878                                 <option>--require</option> is passed
 879                                 the generated graph will show both
 880                                 ordering and requirement
 881                                 dependencies.</para></listitem>
 882                         </varlistentry>
 883                         <varlistentry>
 884                                 <term><command>snapshot [NAME]</command></term>
 885
 886                                 <listitem><para>Create a snapshot. If
 887                                 a snapshot name is specified, the new
 888                                 snapshot will be named after it. If
 889                                 none is specified an automatic
 890                                 snapshot name is generated. In either
 891                                 case, the snapshot name used is
 892                                 printed to STDOUT, unless
 893                                 <option>--quiet</option> is
 894                                 specified.</para>
 895
 896                                 <para>A snapshot refers to a saved
 897                                 state of the systemd manager. It is
 898                                 implemented itself as a unit that is
 899                                 generated dynamically with this
 900                                 command and has dependencies on all
 901                                 units active at the time. At a later
 902                                 time the user may return to this state
 903                                 by using the
 904                                 <command>isolate</command> command on
 905                                 the snapshot unit.</para></listitem>
 906
 907                                 <para>Snapshots are only useful for
 908                                 saving and restoring which units are
 909                                 running or are stopped, they do not
 910                                 save/restore any other
 911                                 state. Snapshots are dynamic and lost
 912                                 on reboot.</para>
 913                         </varlistentry>
 914                         <varlistentry>
 915                                 <term><command>delete [NAME...]</command></term>
 916
 917                                 <listitem><para>Remove a snapshot
 918                                 previously created with
 919                                 <command>snapshot</command>.</para></listitem>
 920                         </varlistentry>
 921                         <varlistentry>
 922                                 <term><command>daemon-reload</command></term>
 923
 924                                 <listitem><para>Reload systemd manager
 925                                 configuration. This will reload all
 926                                 unit files and recreate the entire
 927                                 dependency tree. While the daemon is
 928                                 reloaded, all sockets systemd listens
 929                                 on on behalf of user configuration will
 930                                 stay accessible.</para> <para>This
 931                                 command should not be confused with
 932                                 the <command>load</command> or
 933                                 <command>reload</command>
 934                                 commands.</para></listitem>
 935                         </varlistentry>
 936                         <varlistentry>
 937                                 <term><command>daemon-reexec</command></term>
 938
 939                                 <listitem><para>Reexecute the systemd
 940                                 manager. This will serialize the
 941                                 manager state, reexecute the process
 942                                 and deserialize the state again. This
 943                                 command is of little use except for
 944                                 debugging and package
 945                                 upgrades. Sometimes it might be
 946                                 helpful as a heavy-weight
 947                                 <command>daemon-reload</command>. While
 948                                 the daemon is reexecuted all sockets
 949                                 systemd listens on on behalf of user
 950                                 configuration will stay
 951                                 accessible.</para></listitem>
 952                         </varlistentry>
 953                         <varlistentry>
 954                                 <term><command>show-environment</command></term>
 955
 956                                 <listitem><para>Dump the systemd
 957                                 manager environment block. The
 958                                 environment block will be dumped in
 959                                 straight-forward form suitable for
 960                                 sourcing into a shell script. This
 961                                 environment block will be passed to
 962                                 all processes the manager
 963                                 spawns.</para></listitem>
 964                         </varlistentry>
 965                         <varlistentry>
 966                                 <term><command>set-environment [NAME=VALUE...]</command></term>
 967
 968                                 <listitem><para>Set one or more
 969                                 systemd manager environment variables,
 970                                 as specified on the command
 971                                 line.</para></listitem>
 972                         </varlistentry>
 973                         <varlistentry>
 974                                 <term><command>unset-environment [NAME...]</command></term>
 975
 976                                 <listitem><para>Unset one or more
 977                                 systemd manager environment
 978                                 variables. If only a variable name is
 979                                 specified it will be removed
 980                                 regardless of its value. If a variable
 981                                 and a value are specified the variable
 982                                 is only removed if it has the
 983                                 specified value.</para></listitem>
 984                         </varlistentry>
 985                         <varlistentry>
 986                                 <term><command>default</command></term>
 987
 988                                 <listitem><para>Enter default
 989                                 mode. This is mostly equivalent to
 990                                 <command>start
 991                                 default.target</command>.</para></listitem>
 992                         </varlistentry>
 993                         <varlistentry>
 994                                 <term><command>rescue</command></term>
 995
 996                                 <listitem><para>Enter rescue
 997                                 mode. This is mostly equivalent to
 998                                 <command>isolate
 999                                 rescue.target</command> but also
1000                                 prints a wall message to all
1001                                 users.</para></listitem>
1002                         </varlistentry>
1003                         <varlistentry>
1004                                 <term><command>emergency</command></term>
1005
1006                                 <listitem><para>Enter emergency
1007                                 mode. This is mostly equivalent to
1008                                 <command>isolate
1009                                 emergency.target</command> but also
1010                                 prints a wall message to all
1011                                 users.</para></listitem>
1012                         </varlistentry>
1013                         <varlistentry>
1014                                 <term><command>halt</command></term>
1015
1016                                 <listitem><para>Shut down and halt the
1017                                 system. This is mostly equivalent to
1018                                 <command>start halt.target</command>
1019                                 but also prints a wall message to all
1020                                 users.  If
1021                                 combined with <option>--force</option>
1022                                 shutdown of all running services is
1023                                 skipped, however all processes are killed
1024                                 and all file systems are unmounted or
1025                                 mounted read-only, immediately
1026                                 followed by the
1027                                 system halt.</para></listitem>
1028                         </varlistentry>
1029                         <varlistentry>
1030                                 <term><command>poweroff</command></term>
1031
1032                                 <listitem><para>Shut down and
1033                                 power-off the system. This is mostly
1034                                 equivalent to <command>start
1035                                 poweroff.target</command> but also
1036                                 prints a wall message to all
1037                                 users. If
1038                                 combined with <option>--force</option>
1039                                 shutdown of all running services is
1040                                 skipped, however all processes are killed
1041                                 and all file systems are unmounted or
1042                                 mounted read-only, immediately
1043                                 followed by the
1044                                 powering off.</para></listitem>
1045                         </varlistentry>
1046                         <varlistentry>
1047                                 <term><command>reboot</command></term>
1048
1049                                 <listitem><para>Shut down and
1050                                 reboot the system. This is mostly
1051                                 equivalent to <command>start
1052                                 reboot.target</command> but also
1053                                 prints a wall message to all
1054                                 users. If
1055                                 combined with <option>--force</option>
1056                                 shutdown of all running services is
1057                                 skipped, however all processes are killed
1058                                 and all file systems are unmounted or
1059                                 mounted read-only, immediately
1060                                 followed by the
1061                                 reboot.</para></listitem>
1062                         </varlistentry>
1063                         <varlistentry>
1064                                 <term><command>kexec</command></term>
1065
1066                                 <listitem><para>Shut down and reboot
1067                                 the system via kexec. This is mostly
1068                                 equivalent to <command>start
1069                                 kexec.target</command> but also prints
1070                                 a wall message to all users. If
1071                                 combined with <option>--force</option>
1072                                 shutdown of all running services is
1073                                 skipped, however all processes are killed
1074                                 and all file systems are unmounted or
1075                                 mounted read-only, immediately
1076                                 followed by the
1077                                 reboot.</para></listitem>
1078                         </varlistentry>
1079                         <varlistentry>
1080                                 <term><command>exit</command></term>
1081
1082                                 <listitem><para>Ask the systemd
1083                                 manager to quit. This is only
1084                                 supported for user service managers
1085                                 (i.e. in conjunction with the
1086                                 <option>--user</option> option) and
1087                                 will fail otherwise.</para></listitem>
1088                         </varlistentry>
1089                 </variablelist>
1090
1091         </refsect1>
1092
1093         <refsect1>
1094                 <title>Exit status</title>
1095
1096                 <para>On success 0 is returned, a non-zero failure
1097                 code otherwise.</para>
1098         </refsect1>
1099
1100         <refsect1>
1101                 <title>Environment</title>
1102
1103                 <variablelist>
1104                         <varlistentry>
1105                                 <term><varname>$SYSTEMD_PAGER</varname></term>
1106                                 <listitem><para>Pager to use when
1107                                 <option>--no-pager</option> is not given;
1108                                 overrides <varname>$PAGER</varname>.  Setting
1109                                 this to an empty string or the value
1110                                 <literal>cat</literal> is equivalent to passing
1111                                 <option>--no-pager</option>.</para></listitem>
1112                         </varlistentry>
1113                 </variablelist>
1114         </refsect1>
1115
1116         <refsect1>
1117                 <title>See Also</title>
1118                 <para>
1119                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1120                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1121                         <citerefentry><refentrytitle>systemd-loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1122                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1123                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1124                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
1125                 </para>
1126         </refsect1>
1127
1128 </refentry>