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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  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
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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 information, 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 information,
 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> </varlistentry>
 198
 199                         <varlistentry>
 200                                 <term><option>--no-pager</option></term>
 201
 202                                 <listitem><para>Do not pipe output into a
 203                                 pager.</para></listitem>
 204                         </varlistentry>
 205
 206                         <varlistentry>
 207                                 <term><option>--system</option></term>
 208
 209                                 <listitem><para>Talk to the systemd
 210                                 system manager. (Default)</para></listitem>
 211                         </varlistentry>
 212
 213                         <varlistentry>
 214                                 <term><option>--user</option></term>
 215
 216                                 <listitem><para>Talk to the systemd
 217                                 manager of the calling user.</para></listitem>
 218                         </varlistentry>
 219
 220                         <varlistentry>
 221                                 <term><option>--order</option></term>
 222                                 <term><option>--require</option></term>
 223
 224                                 <listitem><para>When used in
 225                                 conjunction with the
 226                                 <command>dot</command> command (see
 227                                 below), selects which dependencies are
 228                                 shown in the dependency graph. If
 229                                 <option>--order</option> is passed
 230                                 only dependencies of type
 231                                 <varname>After=</varname> or
 232                                 <varname>Before=</varname> are
 233                                 shown. If <option>--require</option>
 234                                 is passed only dependencies of type
 235                                 <varname>Requires=</varname>,
 236                                 <varname>RequiresOverridable=</varname>,
 237                                 <varname>Requisite=</varname>,
 238                                 <varname>RequisiteOverridable=</varname>,
 239                                 <varname>Wants=</varname> and
 240                                 <varname>Conflicts=</varname> are
 241                                 shown. If neither is passed, shows
 242                                 dependencies of all these
 243                                 types.</para></listitem>
 244                         </varlistentry>
 245
 246                         <varlistentry>
 247                                 <term><option>--no-wall</option></term>
 248
 249                                 <listitem><para>Don't send wall
 250                                 message before
 251                                 halt, power-off, reboot.</para></listitem>
 252                         </varlistentry>
 253
 254                         <varlistentry>
 255                                 <term><option>--global</option></term>
 256
 257                                 <listitem><para>When used with
 258                                 <command>enable</command> and
 259                                 <command>disable</command>, operate on the
 260                                 global user configuration
 261                                 directory, thus enabling or disabling
 262                                 a unit file globally for all future
 263                                 logins of all users.</para></listitem>
 264                         </varlistentry>
 265
 266                         <varlistentry>
 267                                 <term><option>--no-reload</option></term>
 268
 269                                 <listitem><para>When used with
 270                                 <command>enable</command> and
 271                                 <command>disable</command>, do not
 272                                 implicitly reload daemon configuration
 273                                 after executing the
 274                                 changes.</para></listitem>
 275                         </varlistentry>
 276
 277                         <varlistentry>
 278                                 <term><option>--no-ask-password</option></term>
 279
 280                                 <listitem><para>When used with
 281                                 <command>start</command> and related
 282                                 commands, disables asking for
 283                                 passwords. Background services may
 284                                 require input of a password or
 285                                 passphrase string, for example to
 286                                 unlock system hard disks or
 287                                 cryptographic certificates. Unless
 288                                 this option is specified and the
 289                                 command is invoked from a terminal
 290                                 <command>systemctl</command> will
 291                                 query the user on the terminal for the
 292                                 necessary secrets. Use this option to
 293                                 switch this behavior off. In this
 294                                 case the password must be supplied by
 295                                 some other means (for example
 296                                 graphical password agents) or the
 297                                 service might fail.</para></listitem>
 298                         </varlistentry>
 299
 300                         <varlistentry>
 301                                 <term><option>--kill-mode=</option></term>
 302
 303                                 <listitem><para>When used with
 304                                 <command>kill</command>, choose the
 305                                 mode how to kill the selected
 306                                 processes. Must be one of
 307                                 <option>control-group</option> or
 308                                 <option>process</option> to select
 309                                 whether to kill the entire control
 310                                 group or only the selected process
 311                                 itself. If omitted defaults to
 312                                 <option>control-group</option> if
 313                                 <option>--kill-who=all</option> is
 314                                 set, or <option>process</option>
 315                                 otherwise. You probably never need to
 316                                 use this switch.</para></listitem>
 317                         </varlistentry>
 318
 319                         <varlistentry>
 320                                 <term><option>--kill-who=</option></term>
 321
 322                                 <listitem><para>When used with
 323                                 <command>kill</command>, choose which
 324                                 processes to kill. Must be one of
 325                                 <option>main</option>,
 326                                 <option>control</option> or
 327                                 <option>all</option> to select whether
 328                                 to kill only the main process of the
 329                                 unit, the control process or all
 330                                 processes of the unit. If omitted
 331                                 defaults to
 332                                 <option>all</option>.</para></listitem>
 333                         </varlistentry>
 334
 335                         <varlistentry>
 336                                 <term><option>--signal=</option></term>
 337                                 <term><option>-s</option></term>
 338
 339                                 <listitem><para>When used with
 340                                 <command>kill</command>, choose which
 341                                 signal to send to selected
 342                                 processes. Must be one of the well
 343                                 known signal specifiers such as
 344                                 SIGTERM, SIGINT or SIGSTOP. If
 345                                 omitted defaults to
 346                                 <option>SIGTERM</option>.</para></listitem>
 347                         </varlistentry>
 348
 349                         <varlistentry>
 350                                 <term><option>--force</option></term>
 351                                 <term><option>-f</option></term>
 352
 353                                 <listitem><para>When used with
 354                                 <command>enable</command>, override any
 355                                 existing conflicting
 356                                 symlinks.</para></listitem>
 357
 358                                 <listitem><para>When used with
 359                                 <command>halt</command>,
 360                                 <command>poweroff</command>,
 361                                 <command>reboot</command> or
 362                                 <command>kexec</command> execute
 363                                 selected operation without shutting
 364                                 down all units. However, all processes
 365                                 will be killed forcibly and all file
 366                                 systems are unmounted or remounted
 367                                 read-only. This is hence a drastic but
 368                                 relatively safe option to request an
 369                                 immediate reboot.</para></listitem>
 370                         </varlistentry>
 371
 372                         <varlistentry>
 373                                 <term><option>--defaults</option></term>
 374
 375                                 <listitem><para>When used with
 376                                 <command>disable</command>, ensures
 377                                 that only the symlinks created by
 378                                 <command>enable</command> are removed,
 379                                 not all symlinks pointing to the unit
 380                                 file that shall be
 381                                 disabled.</para></listitem>
 382                         </varlistentry>
 383
 384                         <varlistentry>
 385                                 <term><option>-H</option></term>
 386                                 <term><option>--host</option></term>
 387
 388                                 <listitem><para>Execute operation
 389                                 remotely. Specify a hostname, or
 390                                 username and hostname separated by @,
 391                                 to connect to. This will use SSH to
 392                                 talk to the remote systemd
 393                                 instance.</para></listitem>
 394                         </varlistentry>
 395
 396                         <varlistentry>
 397                                 <term><option>-P</option></term>
 398                                 <term><option>--privileged</option></term>
 399
 400                                 <listitem><para>Acquire privileges via
 401                                 PolicyKit before executing the
 402                                 operation.</para></listitem>
 403                         </varlistentry>
 404                 </variablelist>
 405
 406                 <para>The following commands are understood:</para>
 407
 408                 <variablelist>
 409                         <varlistentry>
 410                                 <term><command>list-units</command></term>
 411
 412                                 <listitem><para>List known units.</para></listitem>
 413                         </varlistentry>
 414                         <varlistentry>
 415                                 <term><command>start [NAME...]</command></term>
 416
 417                                 <listitem><para>Start (activate) one
 418                                 or more units specified on the command
 419                                 line.</para></listitem>
 420                         </varlistentry>
 421                         <varlistentry>
 422                                 <term><command>stop [NAME...]</command></term>
 423
 424                                 <listitem><para>Stop (deactivate) one
 425                                 or more units specified on the command
 426                                 line.</para></listitem>
 427                         </varlistentry>
 428                         <varlistentry>
 429                                 <term><command>reload [NAME...]</command></term>
 430
 431                                 <listitem><para>Asks all units listed
 432                                 on the command line to reload their
 433                                 configuration. Note that this will
 434                                 reload the service-specific
 435                                 configuration, not the unit
 436                                 configuration file of systemd. If you
 437                                 want systemd to reload the
 438                                 configuration file of a unit use the
 439                                 <command>daemon-reload</command>
 440                                 command. In other words: for the
 441                                 example case of Apache, this will
 442                                 reload Apache's
 443                                 <filename>httpd.conf</filename> in the
 444                                 web server, not the
 445                                 <filename>apache.service</filename>
 446                                 systemd unit file. </para>
 447
 448                                 <para>This command should not be
 449                                 confused with the
 450                                 <command>daemon-reload</command> or
 451                                 <command>load</command>
 452                                 commands.</para></listitem>
 453
 454                         </varlistentry>
 455                         <varlistentry>
 456                                 <term><command>restart [NAME...]</command></term>
 457
 458                                 <listitem><para>Restart one or more
 459                                 units specified on the command
 460                                 line. If the units are not running yet
 461                                 they will be
 462                                 started.</para></listitem>
 463                         </varlistentry>
 464                         <varlistentry>
 465                                 <term><command>try-restart [NAME...]</command></term>
 466
 467                                 <listitem><para>Restart one or more
 468                                 units specified on the command
 469                                 line if the units are running. Do
 470                                 nothing if units are not running.
 471                                 Note that for compatibility
 472                                 with Red Hat init scripts
 473                                 <command>condrestart</command> is
 474                                 equivalent to this command.</para></listitem>
 475                         </varlistentry>
 476                         <varlistentry>
 477                                 <term><command>reload-or-restart [NAME...]</command></term>
 478
 479                                 <listitem><para>Reload one or more
 480                                 units if they support it. If not,
 481                                 restart them instead. If the units
 482                                 are not running yet they will be
 483                                 started.</para></listitem>
 484                         </varlistentry>
 485                         <varlistentry>
 486                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 487
 488                                 <listitem><para>Reload one or more
 489                                 units if they support it. If not,
 490                                 restart them instead. Do nothing if
 491                                 the units are not running. Note that
 492                                 for compatibility with SysV init
 493                                 scripts
 494                                 <command>force-reload</command> is
 495                                 equivalent to this
 496                                 command.</para></listitem>
 497                         </varlistentry>
 498                         <varlistentry>
 499                                 <term><command>isolate [NAME]</command></term>
 500
 501                                 <listitem><para>Start the unit
 502                                 specified on the command line and its
 503                                 dependencies and stop all others.</para>
 504
 505                                 <para>This is similar to changing the
 506                                 runlevel in a traditional init system. The
 507                                 <command>isolate</command> command will
 508                                 immediately stop processes that are not
 509                                 enabled in the new unit, possibly including
 510                                 the graphical environment or terminal you
 511                                 are currently using.</para>
 512
 513                                 <para>Note that this works only on units
 514                                 where <option>AllowIsolate=</option> is
 515                                 enabled. See
 516                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 517                                 for details.</para></listitem>
 518                         </varlistentry>
 519                         <varlistentry>
 520                                 <term><command>kill [NAME...]</command></term>
 521
 522                                 <listitem><para>Send a signal to one
 523                                 or more processes of the unit. Use
 524                                 <option>--kill-who=</option> to select
 525                                 which process to kill. Use
 526                                 <option>--kill-mode=</option> to
 527                                 select the kill mode and
 528                                 <option>--signal=</option> to select
 529                                 the signal to send.</para></listitem>
 530                         </varlistentry>
 531                         <varlistentry>
 532                                 <term><command>is-active [NAME...]</command></term>
 533
 534                                 <listitem><para>Check whether any of
 535                                 the specified units are active
 536                                 (i.e. running). Returns an exit code
 537                                 0 if at least one is active, non-zero
 538                                 otherwise. Unless
 539                                 <option>--quiet</option> is specified
 540                                 this will also print the current unit
 541                                 state to STDOUT.</para></listitem>
 542                         </varlistentry>
 543                         <varlistentry>
 544                                 <term><command>status [NAME...|PID...]</command></term>
 545
 546                                 <listitem><para>Show terse runtime
 547                                 status information about one or more
 548                                 units. This function is intended to
 549                                 generate human-readable output. If you
 550                                 are looking for computer-parsable
 551                                 output, use <command>show</command>
 552                                 instead. If a PID is passed
 553                                 information about the unit the process
 554                                 of the PID belongs to is
 555                                 shown.</para></listitem>
 556                         </varlistentry>
 557                         <varlistentry>
 558                                 <term><command>show [NAME...|JOB...]</command></term>
 559
 560                                 <listitem><para>Show properties of one
 561                                 or more units, jobs or the manager
 562                                 itself. If no argument is specified
 563                                 properties of the manager will be
 564                                 shown. If a unit name is specified
 565                                 properties of the unit is shown, and
 566                                 if a job id is specified properties of
 567                                 the job is shown. By default, empty
 568                                 properties are suppressed. Use
 569                                 <option>--all</option> to show those
 570                                 too. To select specific properties to
 571                                 show use
 572                                 <option>--property=</option>. This
 573                                 command is intended to be used
 574                                 whenever computer-parsable output is
 575                                 required. Use
 576                                 <command>status</command> if you are
 577                                 looking for formatted human-readable
 578                                 output.</para></listitem>
 579                         </varlistentry>
 580
 581                         <varlistentry>
 582                                 <term><command>reset-failed [NAME...]</command></term>
 583
 584                                 <listitem><para>Reset the
 585                                 '<literal>failed</literal>' state of the
 586                                 specified units, or if no unit name is
 587                                 passed of all units. When a unit fails
 588                                 in some way (i.e. process exiting with
 589                                 non-zero error code, terminating
 590                                 abnormally or timing out) it will
 591                                 automatically enter the
 592                                 '<literal>failed</literal>' state and
 593                                 its exit code and status is recorded
 594                                 for introspection by the administrator
 595                                 until the service is restarted or
 596                                 reset with this
 597                                 command.</para></listitem>
 598                         </varlistentry>
 599
 600                         <varlistentry>
 601                                 <term><command>enable [NAME...]</command></term>
 602
 603                                 <listitem><para>Enable one or more
 604                                 unit files, as specified on the
 605                                 command line. This will create a
 606                                 number of symlinks as encoded in the
 607                                 <literal>[Install]</literal> sections
 608                                 of the unit files. After the symlinks
 609                                 have been created the systemd
 610                                 configuration is reloaded (in a way
 611                                 that is equivalent to
 612                                 <command>daemon-reload</command>) to
 613                                 ensure the changes are taken into
 614                                 account immediately. Note that this
 615                                 does not have the effect that any of
 616                                 the units enabled are also started at
 617                                 the same time. If this is desired a
 618                                 separate <command>start</command>
 619                                 command must be invoked for the
 620                                 unit.</para>
 621
 622                                 <para>This command will
 623                                 print the actions executed. This
 624                                 output may be suppressed by passing
 625                                 <option>--quiet</option>.</para>
 626
 627                                 <para>Note that this operation creates
 628                                 only the suggested symlinks for the
 629                                 units. While this command is the
 630                                 recommended way to manipulate the unit
 631                                 configuration directory, the
 632                                 administrator is free to make
 633                                 additional changes manually, by
 634                                 placing or removing symlinks in the
 635                                 directory. This is particularly useful
 636                                 to create configurations that deviate
 637                                 from the suggested default
 638                                 installation. In this case the
 639                                 administrator must make sure to invoke
 640                                 <command>daemon-reload</command>
 641                                 manually as necessary, to ensure his
 642                                 changes are taken into account.</para>
 643
 644                                 <para>Enabling units should not be
 645                                 confused with starting (activating)
 646                                 units, as done by the
 647                                 <command>start</command>
 648                                 command. Enabling and starting units
 649                                 is orthogonal: units may be enabled
 650                                 without being started and started
 651                                 without being enabled. Enabling simply
 652                                 hooks the unit into various suggested
 653                                 places (for example, so that the unit
 654                                 is automatically started on boot or
 655                                 when a particular kind of hardware is
 656                                 plugged in). Starting actually spawns
 657                                 the daemon process (in case of service
 658                                 units), or binds the socket (in case
 659                                 of socket units), and so
 660                                 on.</para>
 661
 662                                 <para>Depending on whether
 663                                 <option>--system</option>,
 664                                 <option>--user</option> or
 665                                 <option>--global</option> is specified
 666                                 this enables the unit for the system,
 667                                 for the calling user only
 668                                 or for all future logins of all
 669                                 users. Note that in the latter case no
 670                                 systemd daemon configuration is
 671                                 reloaded.</para>
 672                                 </listitem>
 673                         </varlistentry>
 674
 675                         <varlistentry>
 676                                 <term><command>disable [NAME...]</command></term>
 677
 678                                 <listitem><para>Disables one or more
 679                                 units. This removes all symlinks to
 680                                 the specified unit files from the unit
 681                                 configuration directory, and hence
 682                                 undoes the changes made by
 683                                 <command>enable</command>. Note
 684                                 however that this by default removes
 685                                 all symlinks to the unit files
 686                                 (i.e. including manual additions), not
 687                                 just those actually created by
 688                                 <command>enable</command>. If only the
 689                                 symlinks that are suggested by default
 690                                 shall be removed, pass
 691                                 <option>--defaults</option>. This
 692                                 implicitly reloads the systemd daemon
 693                                 configuration after completing the
 694                                 disabling of the units. Note that this
 695                                 command does not implicitly stop the
 696                                 units that is being disabled. If this
 697                                 is desired an additional
 698                                 <command>stop</command>command should
 699                                 be executed afterwards.</para>
 700
 701                                 <para>This command will print the
 702                                 actions executed. This output may be
 703                                 suppressed by passing
 704                                 <option>--quiet</option>.</para>
 705                                 </listitem>
 706
 707                                 <para>This command honors
 708                                 <option>--system</option>,
 709                                 <option>--user</option>,
 710                                 <option>--global</option> in a similar
 711                                 way as
 712                                 <command>enable</command>.</para>
 713                         </varlistentry>
 714
 715                         <varlistentry>
 716                                 <term><command>is-enabled [NAME...]</command></term>
 717
 718                                 <listitem><para>Checks whether any of
 719                                 the specified unit files is enabled
 720                                 (as with
 721                                 <command>enable</command>). Returns an
 722                                 exit code of 0 if at least one is
 723                                 enabled, non-zero
 724                                 otherwise.</para></listitem>
 725                         </varlistentry>
 726
 727                         <varlistentry>
 728                                 <term><command>load [NAME...]</command></term>
 729
 730                                 <listitem><para>Load one or more units
 731                                 specified on the command line. This
 732                                 will simply load their configuration
 733                                 from disk, but not start them. To
 734                                 start them you need to use the
 735                                 <command>start</command> command which
 736                                 will implicitly load a unit that has
 737                                 not been loaded yet. Note that systemd
 738                                 garbage collects loaded units that are
 739                                 not active or referenced by an active
 740                                 unit. This means that units loaded
 741                                 this way will usually not stay loaded
 742                                 for long. Also note that this command
 743                                 cannot be used to reload unit
 744                                 configuration. Use the
 745                                 <command>daemon-reload</command>
 746                                 command for that. All in all, this
 747                                 command is of little use except for
 748                                 debugging.</para>
 749                                 <para>This command should not be
 750                                 confused with the
 751                                 <command>daemon-reload</command> or
 752                                 <command>reload</command>
 753                                 commands.</para></listitem>
 754                         </varlistentry>
 755                         <varlistentry>
 756                                 <term><command>list-jobs</command></term>
 757
 758                                 <listitem><para>List jobs that are in progress.</para></listitem>
 759                         </varlistentry>
 760                         <varlistentry>
 761                                 <term><command>cancel [JOB...]</command></term>
 762
 763                                 <listitem><para>Cancel one or more
 764                                 jobs specified on the command line by
 765                                 their numeric job
 766                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 767                         </varlistentry>
 768                         <varlistentry>
 769                                 <term><command>monitor</command></term>
 770
 771                                 <listitem><para>Monitor unit/job
 772                                 changes. This is mostly useful for
 773                                 debugging purposes and prints a line
 774                                 each time systemd loads or unloads a
 775                                 unit configuration file, or a unit
 776                                 property changes.</para></listitem>
 777                         </varlistentry>
 778                         <varlistentry>
 779                                 <term><command>dump</command></term>
 780
 781                                 <listitem><para>Dump server
 782                                 status. This will output a (usually
 783                                 very long) human readable manager
 784                                 status dump. Its format is subject to
 785                                 change without notice and should not
 786                                 be parsed by
 787                                 applications.</para></listitem>
 788                         </varlistentry>
 789                         <varlistentry>
 790                                 <term><command>dot</command></term>
 791
 792                                 <listitem><para>Generate textual
 793                                 dependency graph description in dot
 794                                 format for further processing with the
 795                                 GraphViz
 796                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 797                                 tool. Use a command line like
 798                                 <command>systemctl dot | dot -Tsvg >
 799                                 systemd.svg</command> to generate a
 800                                 graphical dependency tree. Unless
 801                                 <option>--order</option> or
 802                                 <option>--require</option> is passed
 803                                 the generated graph will show both
 804                                 ordering and requirement
 805                                 dependencies.</para></listitem>
 806                         </varlistentry>
 807                         <varlistentry>
 808                                 <term><command>snapshot [NAME]</command></term>
 809
 810                                 <listitem><para>Create a snapshot. If
 811                                 a snapshot name is specified, the new
 812                                 snapshot will be named after it. If
 813                                 none is specified an automatic
 814                                 snapshot name is generated. In either
 815                                 case, the snapshot name used is
 816                                 printed to STDOUT, unless
 817                                 <option>--quiet</option> is
 818                                 specified.</para>
 819
 820                                 <para>A snapshot refers to a saved
 821                                 state of the systemd manager. It is
 822                                 implemented itself as a unit that is
 823                                 generated dynamically with this
 824                                 command and has dependencies on all
 825                                 units active at the time. At a later
 826                                 time the user may return to this state
 827                                 by using the
 828                                 <command>isolate</command> command on
 829                                 the snapshot unit.</para></listitem>
 830
 831                                 <para>Snapshots are only useful for
 832                                 saving and restoring which units are
 833                                 running or are stopped, they do not
 834                                 save/restore any other
 835                                 state. Snapshots are dynamic and lost
 836                                 on reboot.</para>
 837                         </varlistentry>
 838                         <varlistentry>
 839                                 <term><command>delete [NAME...]</command></term>
 840
 841                                 <listitem><para>Remove a snapshot
 842                                 previously created with
 843                                 <command>snapshot</command>.</para></listitem>
 844                         </varlistentry>
 845                         <varlistentry>
 846                                 <term><command>daemon-reload</command></term>
 847
 848                                 <listitem><para>Reload systemd manager
 849                                 configuration. This will reload all
 850                                 unit files and recreate the entire
 851                                 dependency tree. While the daemon is
 852                                 reloaded, all sockets systemd listens
 853                                 on on behalf of user configuration will
 854                                 stay accessible.</para> <para>This
 855                                 command should not be confused with
 856                                 the <command>load</command> or
 857                                 <command>reload</command>
 858                                 commands.</para></listitem>
 859                         </varlistentry>
 860                         <varlistentry>
 861                                 <term><command>daemon-reexec</command></term>
 862
 863                                 <listitem><para>Reexecute the systemd
 864                                 manager. This will serialize the
 865                                 manager state, reexecute the process
 866                                 and deserialize the state again. This
 867                                 command is of little use except for
 868                                 debugging and package
 869                                 upgrades. Sometimes it might be
 870                                 helpful as a heavy-weight
 871                                 <command>daemon-reload</command>. While
 872                                 the daemon is reexecuted all sockets
 873                                 systemd listens on on behalf of user
 874                                 configuration will stay
 875                                 accessible.</para></listitem>
 876                         </varlistentry>
 877                         <varlistentry>
 878                                 <term><command>show-environment</command></term>
 879
 880                                 <listitem><para>Dump the systemd
 881                                 manager environment block. The
 882                                 environment block will be dumped in
 883                                 straight-forward form suitable for
 884                                 sourcing into a shell script. This
 885                                 environment block will be passed to
 886                                 all processes the manager
 887                                 spawns.</para></listitem>
 888                         </varlistentry>
 889                         <varlistentry>
 890                                 <term><command>set-environment [NAME=VALUE...]</command></term>
 891
 892                                 <listitem><para>Set one or more
 893                                 systemd manager environment variables,
 894                                 as specified on the command
 895                                 line.</para></listitem>
 896                         </varlistentry>
 897                         <varlistentry>
 898                                 <term><command>unset-environment [NAME...]</command></term>
 899
 900                                 <listitem><para>Unset one or more
 901                                 systemd manager environment
 902                                 variables. If only a variable name is
 903                                 specified it will be removed
 904                                 regardless of its value. If a variable
 905                                 and a value are specified the variable
 906                                 is only removed if it has the
 907                                 specified value.</para></listitem>
 908                         </varlistentry>
 909                         <varlistentry>
 910                                 <term><command>default</command></term>
 911
 912                                 <listitem><para>Enter default
 913                                 mode. This is mostly equivalent to
 914                                 <command>start
 915                                 default.target</command>.</para></listitem>
 916                         </varlistentry>
 917                         <varlistentry>
 918                                 <term><command>rescue</command></term>
 919
 920                                 <listitem><para>Enter rescue
 921                                 mode. This is mostly equivalent to
 922                                 <command>isolate
 923                                 rescue.target</command> but also
 924                                 prints a wall message to all
 925                                 users.</para></listitem>
 926                         </varlistentry>
 927                         <varlistentry>
 928                                 <term><command>emergency</command></term>
 929
 930                                 <listitem><para>Enter emergency
 931                                 mode. This is mostly equivalent to
 932                                 <command>isolate
 933                                 emergency.target</command> but also
 934                                 prints a wall message to all
 935                                 users.</para></listitem>
 936                         </varlistentry>
 937                         <varlistentry>
 938                                 <term><command>halt</command></term>
 939
 940                                 <listitem><para>Shut down and halt the
 941                                 system. This is mostly equivalent to
 942                                 <command>start halt.target</command>
 943                                 but also prints a wall message to all
 944                                 users.  If
 945                                 combined with <option>--force</option>
 946                                 shutdown of all running services is
 947                                 skipped, however all processes are killed
 948                                 and all file systems are unmounted or
 949                                 mounted read-only, immediately
 950                                 followed by the
 951                                 system halt.</para></listitem>
 952                         </varlistentry>
 953                         <varlistentry>
 954                                 <term><command>poweroff</command></term>
 955
 956                                 <listitem><para>Shut down and
 957                                 power-off the system. This is mostly
 958                                 equivalent to <command>start
 959                                 poweroff.target</command> but also
 960                                 prints a wall message to all
 961                                 users. If
 962                                 combined with <option>--force</option>
 963                                 shutdown of all running services is
 964                                 skipped, however all processes are killed
 965                                 and all file systems are unmounted or
 966                                 mounted read-only, immediately
 967                                 followed by the
 968                                 powering off.</para></listitem>
 969                         </varlistentry>
 970                         <varlistentry>
 971                                 <term><command>reboot</command></term>
 972
 973                                 <listitem><para>Shut down and
 974                                 reboot the system. This is mostly
 975                                 equivalent to <command>start
 976                                 reboot.target</command> but also
 977                                 prints a wall message to all
 978                                 users. If
 979                                 combined with <option>--force</option>
 980                                 shutdown of all running services is
 981                                 skipped, however all processes are killed
 982                                 and all file systems are unmounted or
 983                                 mounted read-only, immediately
 984                                 followed by the
 985                                 reboot.</para></listitem>
 986                         </varlistentry>
 987                         <varlistentry>
 988                                 <term><command>kexec</command></term>
 989
 990                                 <listitem><para>Shut down and reboot
 991                                 the system via kexec. This is mostly
 992                                 equivalent to <command>start
 993                                 kexec.target</command> but also prints
 994                                 a wall message to all users. If
 995                                 combined with <option>--force</option>
 996                                 shutdown of all running services is
 997                                 skipped, however all processes are killed
 998                                 and all file systems are unmounted or
 999                                 mounted read-only, immediately
1000                                 followed by the
1001                                 reboot.</para></listitem>
1002                         </varlistentry>
1003                         <varlistentry>
1004                                 <term><command>exit</command></term>
1005
1006                                 <listitem><para>Ask the systemd
1007                                 manager to quit. This is only
1008                                 supported for user service managers
1009                                 (i.e. in conjunction with the
1010                                 <option>--user</option> option) and
1011                                 will fail otherwise.</para></listitem>
1012                         </varlistentry>
1013                 </variablelist>
1014
1015         </refsect1>
1016
1017         <refsect1>
1018                 <title>Exit status</title>
1019
1020                 <para>On success 0 is returned, a non-zero failure
1021                 code otherwise.</para>
1022         </refsect1>
1023
1024         <refsect1>
1025                 <title>See Also</title>
1026                 <para>
1027                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1028                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1029                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1030                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1031                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
1032                 </para>
1033         </refsect1>
1034
1035 </refentry>