man/systemctl.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4
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   6   This file is part of systemd.
   7
   8   Copyright 2010 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU General Public License as published by
  12   the Free Software Foundation; either version 2 of the License, or
  13   (at your option) any later version.
  14
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  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   General Public License for more details.
  19
  20   You should have received a copy of the GNU General Public License
  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 session 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 session 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>--type=</option></term>
  81                                 <term><option>-t</option></term>
  82
  83                                 <listitem><para>When listing units,
  84                                 limit display to certain unit
  85                                 types. If not specified units of all
  86                                 types will be shown. The argument
  87                                 should be a unit type name such as
  88                                 <option>service</option>,
  89                                 <option>socket</option> and
  90                                 similar.</para></listitem>
  91                         </varlistentry>
  92
  93                         <varlistentry>
  94                                 <term><option>--property=</option></term>
  95                                 <term><option>-p</option></term>
  96
  97                                 <listitem><para>When showing
  98                                 unit/job/manager information, limit
  99                                 display to certain properties as
 100                                 specified as argument. If not
 101                                 specified all set properties are
 102                                 shown. The argument should be a
 103                                 property name, such as
 104                                 <literal>MainPID</literal>. If
 105                                 specified more than once all
 106                                 properties with the specified names
 107                                 are shown.</para></listitem>
 108                         </varlistentry>
 109
 110                         <varlistentry>
 111                                 <term><option>--all</option></term>
 112                                 <term><option>-a</option></term>
 113
 114                                 <listitem><para>When listing units,
 115                                 show all units, regardless of their
 116                                 state, including inactive units. When
 117                                 showing unit/job/manager information,
 118                                 show all properties regardless whether
 119                                 they are set or not.</para></listitem>
 120                         </varlistentry>
 121
 122                         <varlistentry>
 123                                 <term><option>--full</option></term>
 124
 125                                 <listitem><para>Do not ellipsize unit
 126                                 names in the output of
 127                                 <command>list-units</command> and
 128                                 <command>list-jobs</command>.</para></listitem>
 129                         </varlistentry>
 130
 131                         <varlistentry>
 132                                 <term><option>--fail</option></term>
 133
 134                                 <listitem><para>If the requested
 135                                 operation conflicts with a pending
 136                                 unfinished job, fail the command. If
 137                                 this is not specified the requested
 138                                 operation will replace the pending job,
 139                                 if necessary.</para></listitem>
 140                         </varlistentry>
 141
 142                         <varlistentry>
 143                                 <term><option>--quiet</option></term>
 144                                 <term><option>-q</option></term>
 145
 146                                 <listitem><para>Suppress output to
 147                                 STDOUT in
 148                                 <command>snapshot</command>,
 149                                 <command>check</command>,
 150                                 <command>enable</command> and
 151                                 <command>disable</command>.</para></listitem>
 152                         </varlistentry>
 153
 154                         <varlistentry>
 155                                 <term><option>--no-block</option></term>
 156
 157                                 <listitem><para>Do not synchronously wait for
 158                                 the requested operation to finish. If this is
 159                                 not specified the job will be verified,
 160                                 enqueued and <command>systemctl</command> will
 161                                 wait until it is completed. By passing this
 162                                 argument it is only verified and
 163                                 enqueued.</para></listitem> </varlistentry>
 164
 165                         <varlistentry>
 166                                 <term><option>--system</option></term>
 167
 168                                 <listitem><para>Talk to the systemd
 169                                 system manager. (Default)</para></listitem>
 170                         </varlistentry>
 171
 172                         <varlistentry>
 173                                 <term><option>--session</option></term>
 174
 175                                 <listitem><para>Talk to the systemd
 176                                 session manager of the calling user.</para></listitem>
 177                         </varlistentry>
 178
 179                         <varlistentry>
 180                                 <term><option>--order</option></term>
 181                                 <term><option>--require</option></term>
 182
 183                                 <listitem><para>When used in
 184                                 conjunction with the
 185                                 <command>dot</command> command (see
 186                                 below), selects which dependencies are
 187                                 shown in the dependency graph. If
 188                                 <option>--order</option> is passed
 189                                 only dependencies of type
 190                                 <varname>After=</varname> or
 191                                 <varname>Before=</varname> are
 192                                 shown. If <option>--require</option>
 193                                 is passed only dependencies of type
 194                                 <varname>Requires=</varname>,
 195                                 <varname>RequiresOverridable=</varname>,
 196                                 <varname>Requisite=</varname>,
 197                                 <varname>RequisiteOverridable=</varname>,
 198                                 <varname>Wants=</varname> and
 199                                 <varname>Conflicts=</varname> are
 200                                 shown. If neither is passed, shows
 201                                 dependencies of all these
 202                                 types.</para></listitem>
 203                         </varlistentry>
 204
 205                         <varlistentry>
 206                                 <term><option>--no-wall</option></term>
 207
 208                                 <listitem><para>Don't send wall
 209                                 message before
 210                                 halt, power-off, reboot.</para></listitem>
 211                         </varlistentry>
 212
 213                         <varlistentry>
 214                                 <term><option>--global</option></term>
 215
 216                                 <listitem><para>When used with
 217                                 <command>enable</command> and
 218                                 <command>disable</command>, operate on the
 219                                 global session configuŕation
 220                                 directory, thus enabling or disabling
 221                                 a unit file globally for all future
 222                                 sessions of all users.</para></listitem>
 223                         </varlistentry>
 224
 225                         <varlistentry>
 226                                 <term><option>--no-reload</option></term>
 227
 228                                 <listitem><para>When used with
 229                                 <command>enable</command> and
 230                                 <command>disable</command>, do not
 231                                 implicitly reload daemon configuration
 232                                 after executing the
 233                                 changes.</para></listitem>
 234                         </varlistentry>
 235
 236                         <varlistentry>
 237                                 <term><option>--force</option></term>
 238
 239                                 <listitem><para>When used with
 240                                 <command>enable</command>, override any
 241                                 existing conflicting
 242                                 symlinks.</para></listitem>
 243                         </varlistentry>
 244
 245                         <varlistentry>
 246                                 <term><option>--defaults</option></term>
 247
 248                                 <listitem><para>When used with
 249                                 <command>disable</command>, ensures
 250                                 that only the symlinks created by
 251                                 <command>enable</command> are removed,
 252                                 not all symlinks pointing to the unit
 253                                 file that shall be
 254                                 disabled.</para></listitem>
 255                         </varlistentry>
 256                 </variablelist>
 257
 258                 <para>The following commands are understood:</para>
 259
 260                 <variablelist>
 261                         <varlistentry>
 262                                 <term><command>list-units</command></term>
 263
 264                                 <listitem><para>List known units.</para></listitem>
 265                         </varlistentry>
 266                         <varlistentry>
 267                                 <term><command>start [NAME...]</command></term>
 268
 269                                 <listitem><para>Start (activate) one
 270                                 or more units specified on the command
 271                                 line.</para></listitem>
 272                         </varlistentry>
 273                         <varlistentry>
 274                                 <term><command>stop [NAME...]</command></term>
 275
 276                                 <listitem><para>Stop (deactivate) one
 277                                 or more units specified on the command
 278                                 line.</para></listitem>
 279                         </varlistentry>
 280                         <varlistentry>
 281                                 <term><command>reload [NAME...]</command></term>
 282
 283                                 <listitem><para>Asks all units listed
 284                                 on the command line to reload their
 285                                 configuration. Note that this will
 286                                 reload the service-specific
 287                                 configuration, not the unit
 288                                 configuration file of systemd. If you
 289                                 want systemd to reload the
 290                                 configuration file of a unit use the
 291                                 <command>daemon-reload</command>
 292                                 command. In other words: for the
 293                                 example case of Apache, this will
 294                                 reload Apache's
 295                                 <filename>httpd.conf</filename> in the
 296                                 web server, not the
 297                                 <filename>apache.service</filename>
 298                                 systemd unit file. </para>
 299
 300                                 <para>This command should not be
 301                                 confused with the
 302                                 <command>daemon-reload</command> or
 303                                 <command>load</command>
 304                                 commands.</para></listitem>
 305
 306                         </varlistentry>
 307                         <varlistentry>
 308                                 <term><command>restart [NAME...]</command></term>
 309
 310                                 <listitem><para>Restart one or more
 311                                 units specified on the command
 312                                 line. If the units are not running yet
 313                                 they will be
 314                                 started.</para></listitem>
 315                         </varlistentry>
 316                         <varlistentry>
 317                                 <term><command>try-restart [NAME...]</command></term>
 318
 319                                 <listitem><para>Restart one or more
 320                                 units specified on the command
 321                                 line. If the units are not running yet
 322                                 the operation will
 323                                 fail.</para></listitem>
 324                         </varlistentry>
 325                         <varlistentry>
 326                                 <term><command>reload-or-restart [NAME...]</command></term>
 327                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 328
 329                                 <listitem><para>Reload one or more
 330                                 units if they support it. If not,
 331                                 restart them instead. Note that for
 332                                 compatibility with SysV and Red Hat
 333                                 init scripts
 334                                 <command>force-reload</command> and
 335                                 <command>condrestart</command> may be
 336                                 used as equivalent commands to
 337                                 <command>reload-or-try-restart</command>.</para></listitem>
 338                         </varlistentry>
 339                         <varlistentry>
 340                                 <term><command>isolate [NAME]</command></term>
 341
 342                                 <listitem><para>Start the unit
 343                                 specified on the command line and its
 344                                 dependencies and stop all
 345                                 others.</para></listitem>
 346                         </varlistentry>
 347                         <varlistentry>
 348                                 <term><command>is-active [NAME...]</command></term>
 349
 350                                 <listitem><para>Check whether any of
 351                                 the specified units is active
 352                                 (i.e. running). Returns an exit code
 353                                 0 if at least one is active, non-zero
 354                                 otherwise. Unless
 355                                 <option>--quiet</option> is specified
 356                                 this will also print the current unit
 357                                 state to STDOUT.</para></listitem>
 358                         </varlistentry>
 359                         <varlistentry>
 360                                 <term><command>status [NAME...|PID...]</command></term>
 361
 362                                 <listitem><para>Show terse runtime
 363                                 status information about one or more
 364                                 units. This function is intended to
 365                                 generate human-readable output. If you
 366                                 are looking for computer-parsable
 367                                 output, use <command>show</command>
 368                                 instead. If a PID is passed
 369                                 information about the unit the process
 370                                 of the PID belongs to is
 371                                 shown.</para></listitem>
 372                         </varlistentry>
 373                         <varlistentry>
 374                                 <term><command>show [NAME...|JOB...]</command></term>
 375
 376                                 <listitem><para>Show properties of one
 377                                 or more units, jobs or the manager
 378                                 itself. If no argument is specified
 379                                 properties of the manager will be
 380                                 shown. If a unit name is specified
 381                                 properties of the unit is shown, and
 382                                 if a job id is specified properties of
 383                                 the job is shown. By default, empty
 384                                 properties are suppressed. Use
 385                                 <option>--all</option> to show those
 386                                 too. To select specific properties to
 387                                 show use
 388                                 <option>--property=</option>. This
 389                                 command is intended to be used
 390                                 whenever computer-parsable output is
 391                                 required. Use
 392                                 <command>status</command> if you are
 393                                 looking for formatted human-readable
 394                                 output.</para></listitem>
 395                         </varlistentry>
 396
 397                         <varlistentry>
 398                                 <term><command>reset-maintenance [NAME...]</command></term>
 399
 400                                 <listitem><para>Reset maintenance
 401                                 state of the specified units, or if no
 402                                 unit name is passed of all units. When
 403                                 a unit fails in some way (i.e. process
 404                                 exiting with non-zero error code,
 405                                 terminating abnormally or timing out)
 406                                 it will automatically enter
 407                                 maintenance state and its exit codes
 408                                 and status is recorded for
 409                                 introspection by the administrator
 410                                 until the service is restarted or
 411                                 reset with this
 412                                 command.</para></listitem>
 413                         </varlistentry>
 414
 415                         <varlistentry>
 416                                 <term><command>enable [NAME...]</command></term>
 417
 418                                 <listitem><para>Enable one or more
 419                                 unit files, as specified on the
 420                                 command line. This will create a
 421                                 number of symlinks as encoded in the
 422                                 <literal>[Install]</literal> sections
 423                                 of the unit files. After the symlinks
 424                                 have been created the systemd
 425                                 configuration is reloaded (in a way
 426                                 that is equivalent to
 427                                 <command>daemon-reload</command>) to
 428                                 ensure the changes are taken into
 429                                 account immediately. Note that this
 430                                 does not have the effect that any of
 431                                 the units enabled are also started at
 432                                 the same time. If this is desired a
 433                                 seperate <command>start</command>
 434                                 command must be invoked for the
 435                                 unit.</para>
 436
 437                                 <para>This command will
 438                                 print the actions executed. This
 439                                 output may be suppressed by passing
 440                                 <option>--quiet</option>.</para>
 441
 442                                 <para>Note that this operation creates
 443                                 only the suggested symlinks for the
 444                                 units. While this command is the
 445                                 recommended way to manipulate the unit
 446                                 configuration directory, the
 447                                 administrator is free to make
 448                                 additional changes manually, by
 449                                 placing or removing symlinks in the
 450                                 directory. This is particular useful
 451                                 to create configurations that deviate
 452                                 from the suggested default
 453                                 installation. In this case the
 454                                 administrator must make sure to invoke
 455                                 <command>daemon-reload</command>
 456                                 manually as necessary, to ensure his
 457                                 changes are taken into account.</para>
 458
 459                                 <para>Enabling units should not be
 460                                 confused with starting (activating)
 461                                 units, as done by the
 462                                 <command>start</command>
 463                                 command. Enabling and starting units
 464                                 is orthogonal: units may be enabled
 465                                 without being started and started
 466                                 without being enabled. Enabling simply
 467                                 hooks the unit into various suggested
 468                                 places (for example, so that the unit
 469                                 is automatically started on boot or
 470                                 when a particular kind of hardware is
 471                                 plugged in). Starting actually spawns
 472                                 the daemon process (in case of service
 473                                 units), or binds the socket (in case
 474                                 of socket units), and so
 475                                 on.</para>
 476
 477                                 <para>Depending on whether
 478                                 <option>--system</option>,
 479                                 <option>--session</option> or
 480                                 <option>--global</option> is specified
 481                                 this enables the unit for the system,
 482                                 for sessions of the calling user only
 483                                 or for all future session of all
 484                                 users. Note that in the latter case no
 485                                 systemd daemon configuration is
 486                                 reloaded.</para>
 487                                 </listitem>
 488                         </varlistentry>
 489
 490                         <varlistentry>
 491                                 <term><command>disable [NAME...]</command></term>
 492
 493                                 <listitem><para>Disables one or more
 494                                 units. This removes all symlinks to
 495                                 the specified unit files from the unit
 496                                 configuration directory, and hence
 497                                 undoes the changes made by
 498                                 <command>enable</command>. Note
 499                                 however that this by default removes
 500                                 all symlinks to the unit files
 501                                 (i.e. including manual additions), not
 502                                 just those actually created by
 503                                 <command>enable</command>. If only the
 504                                 symlinks that are suggested by default
 505                                 shall be removed, pass
 506                                 <option>--defaults</option>. This
 507                                 implicitly reloads the systemd daemon
 508                                 configuration after completing the
 509                                 disabling of the units. Note that this
 510                                 command does not implicitly stop the
 511                                 units that is being disabled. If this
 512                                 is desired an additional
 513                                 <command>stop</command>command should
 514                                 be executed afterwards.</para>
 515
 516                                 <para>This command will print the
 517                                 actions executed. This output may be
 518                                 suppressed by passing
 519                                 <option>--quiet</option>.</para>
 520                                 </listitem>
 521
 522                                 <para>This command honours
 523                                 <option>--system</option>,
 524                                 <option>--session</option>,
 525                                 <option>--global</option> in a similar
 526                                 way as
 527                                 <command>enable</command>.</para>
 528                         </varlistentry>
 529
 530                         <varlistentry>
 531                                 <term><command>is-enabled [NAME...]</command></term>
 532
 533                                 <listitem><para>Checks whether any of
 534                                 the specified unit files is enabled
 535                                 (as with
 536                                 <command>enable</command>). Returns an
 537                                 exit code of 0 if at least one is
 538                                 enabled, non-zero
 539                                 otherwise.</para></listitem>
 540                         </varlistentry>
 541
 542                         <varlistentry>
 543                                 <term><command>load [NAME...]</command></term>
 544
 545                                 <listitem><para>Load one or more units
 546                                 specified on the command line. This
 547                                 will simply load their configuration
 548                                 from disk, but not start them. To
 549                                 start them you need to use the
 550                                 <command>start</command> command which
 551                                 will implicitly load a unit that has
 552                                 not been loaded yet. Note that systemd
 553                                 garbage collects loaded units that are
 554                                 not active or referenced by an active
 555                                 unit. This means that units loaded
 556                                 this way will usually not stay loaded
 557                                 for long. Also note that this command
 558                                 cannot be used to reload unit
 559                                 configuration. Use the
 560                                 <command>daemon-reload</command>
 561                                 command for that. All in all, this
 562                                 command is of little use except for
 563                                 debugging.</para>
 564                                 <para>This command should not be
 565                                 confused with the
 566                                 <command>daemon-reload</command> or
 567                                 <command>reload</command>
 568                                 commands.</para></listitem>
 569                         </varlistentry>
 570                         <varlistentry>
 571                                 <term><command>list-jobs</command></term>
 572
 573                                 <listitem><para>List jobs that are in progress.</para></listitem>
 574                         </varlistentry>
 575                         <varlistentry>
 576                                 <term><command>cancel [JOB...]</command></term>
 577
 578                                 <listitem><para>Cancel one or more
 579                                 jobs specified on the command line by
 580                                 their numeric job
 581                                 IDs. If not job id is specified cancels all jobs that are pending.</para></listitem>
 582                         </varlistentry>
 583                         <varlistentry>
 584                                 <term><command>monitor</command></term>
 585
 586                                 <listitem><para>Monitor unit/job
 587                                 changes. This is mostly useful for
 588                                 debugging purposes and prints a line
 589                                 each time systemd loads or unloads a
 590                                 unit configuration file, or a unit
 591                                 property changes.</para></listitem>
 592                         </varlistentry>
 593                         <varlistentry>
 594                                 <term><command>dump</command></term>
 595
 596                                 <listitem><para>Dump server
 597                                 status. This will output a (usually
 598                                 very long) human readable manager
 599                                 status dump. Its format is subject to
 600                                 change without notice and should not
 601                                 be parsed by
 602                                 applications.</para></listitem>
 603                         </varlistentry>
 604                         <varlistentry>
 605                                 <term><command>dot</command></term>
 606
 607                                 <listitem><para>Generate textual
 608                                 dependency graph description in dot
 609                                 format for further processing with the
 610                                 GraphViz
 611                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 612                                 tool. Use a command line like
 613                                 <command>systemctl dot | dot -Tsvg >
 614                                 systemd.svg</command> to generate a
 615                                 graphical dependency tree. Unless
 616                                 <option>--order</option> or
 617                                 <option>--require</option> is passed
 618                                 the generated graph will show both
 619                                 ordering and requirement
 620                                 dependencies.</para></listitem>
 621                         </varlistentry>
 622                         <varlistentry>
 623                                 <term><command>snapshot [NAME]</command></term>
 624
 625                                 <listitem><para>Create a snapshot. If
 626                                 a snapshot name is specified, the new
 627                                 snapshot will be named after it. If
 628                                 none is specified an automatic
 629                                 snapshot name is generated. In either
 630                                 case, the snapshot name used is
 631                                 printed to STDOUT, unless
 632                                 <option>--quiet</option> is
 633                                 specified.</para>
 634
 635                                 <para>A snapshot refers to a saved
 636                                 state of the systemd manager. It is
 637                                 implemented itself as unit that is
 638                                 generated dynamically with this
 639                                 command and has dependencies on all
 640                                 units active at the time. At a later
 641                                 time the user may return to this state
 642                                 by using the
 643                                 <command>isolate</command> command on
 644                                 the snapshot unit.</para></listitem>
 645
 646                                 <para>Snapshots are only useful for
 647                                 saving and restoring which units are
 648                                 running or are stopped, they do not
 649                                 save/restore any other
 650                                 state. Snapshots are dynamic and lost
 651                                 on reboot.</para>
 652                         </varlistentry>
 653                         <varlistentry>
 654                                 <term><command>delete [NAME...]</command></term>
 655
 656                                 <listitem><para>Remove a snapshot
 657                                 previously created with
 658                                 <command>snapshot</command>.</para></listitem>
 659                         </varlistentry>
 660                         <varlistentry>
 661                                 <term><command>daemon-reload</command></term>
 662
 663                                 <listitem><para>Reload systemd manager
 664                                 configuration. This will reload all
 665                                 unit files and recreate the entire
 666                                 dependency tree. While the daemon is
 667                                 reloaded, all sockets systemd listens
 668                                 on on behalf of user configuration will
 669                                 stay accessible.</para> <para>This
 670                                 command should not be confused with
 671                                 the <command>load</command> or
 672                                 <command>reload</command>
 673                                 commands.</para></listitem>
 674                         </varlistentry>
 675                         <varlistentry>
 676                                 <term><command>daemon-reexec</command></term>
 677
 678                                 <listitem><para>Reexecute the systemd
 679                                 manager. This will serialize the
 680                                 manager state, reexecute the process
 681                                 and deserialize the state again. This
 682                                 command is of little use except for
 683                                 debugging and package
 684                                 upgrades. Sometimes it might be
 685                                 helpful as a heavy-weight
 686                                 <command>daemon-reload</command>. While
 687                                 the daemon is reexecuted all sockets
 688                                 systemd listens on on behalf of user
 689                                 configuration will stay
 690                                 accessible.</para></listitem>
 691                         </varlistentry>
 692                         <varlistentry>
 693                                 <term><command>daemon-exit</command></term>
 694
 695                                 <listitem><para>Ask the systemd
 696                                 manager to quit. This is only
 697                                 supported for session managers
 698                                 (i.e. in conjunction with the
 699                                 <option>--session</option> option) and
 700                                 will fail otherwise.</para></listitem>
 701                         </varlistentry>
 702                         <varlistentry>
 703                                 <term><command>show-environment</command></term>
 704
 705                                 <listitem><para>Dump the systemd
 706                                 manager environment block. The
 707                                 environment block will be dumped in
 708                                 straight-forward form suitable for
 709                                 sourcing into a shell script. This
 710                                 environment block will be passed to
 711                                 all processes the manager
 712                                 spawns.</para></listitem>
 713                         </varlistentry>
 714                         <varlistentry>
 715                                 <term><command>set-environment [NAME=VALUE...]</command></term>
 716
 717                                 <listitem><para>Set one or more
 718                                 systemd manager environment variables,
 719                                 as specified on the command
 720                                 line.</para></listitem>
 721                         </varlistentry>
 722                         <varlistentry>
 723                                 <term><command>unset-environment [NAME...]</command></term>
 724
 725                                 <listitem><para>Unset one or more
 726                                 systemd manager environment
 727                                 variables. If only a variable name is
 728                                 specified it will be removed
 729                                 regardless of its value. If a variable
 730                                 and a value are specified the variable
 731                                 is only removed if it has the
 732                                 specified value.</para></listitem>
 733                         </varlistentry>
 734
 735                         <varlistentry>
 736                                 <term><command>halt</command></term>
 737
 738                                 <listitem><para>Shut down and halt the
 739                                 system. This is mostly equivalent to
 740                                 <command>start halt.target</command>
 741                                 but also prints a wall message to all
 742                                 users.</para></listitem>
 743                         </varlistentry>
 744                         <varlistentry>
 745                                 <term><command>poweroff</command></term>
 746
 747                                 <listitem><para>Shut down and
 748                                 power-off the system. This is mostly
 749                                 equivalent to <command>start
 750                                 poweroff.target</command> but also
 751                                 prints a wall message to all
 752                                 users.</para></listitem>
 753                         </varlistentry>
 754                         <varlistentry>
 755                                 <term><command>reboot</command></term>
 756
 757                                 <listitem><para>Shut down and
 758                                 reboot the system. This is mostly
 759                                 equivalent to <command>start
 760                                 reboot.target</command> but also
 761                                 prints a wall message to all
 762                                 users.</para></listitem>
 763                         </varlistentry>
 764                         <varlistentry>
 765                                 <term><command>default</command></term>
 766
 767                                 <listitem><para>Enter default
 768                                 mode. This is mostly equivalent to
 769                                 <command>start
 770                                 default.target</command>.</para></listitem>
 771                         </varlistentry>
 772                         <varlistentry>
 773                                 <term><command>rescue</command></term>
 774
 775                                 <listitem><para>Enter rescue
 776                                 mode. This is mostly equivalent to
 777                                 <command>isolate
 778                                 rescue.target</command> but also
 779                                 prints a wall message to all
 780                                 users.</para></listitem>
 781                         </varlistentry>
 782                         <varlistentry>
 783                                 <term><command>emergency</command></term>
 784
 785                                 <listitem><para>Enter emergency
 786                                 mode. This is mostly equivalent to
 787                                 <command>isolate
 788                                 emergency.target</command> but also
 789                                 prints a wall message to all
 790                                 users.</para></listitem>
 791                         </varlistentry>
 792                 </variablelist>
 793
 794         </refsect1>
 795
 796         <refsect1>
 797                 <title>Exit status</title>
 798
 799                 <para>On success 0 is returned, a non-zero failure
 800                 code otherwise.</para>
 801         </refsect1>
 802
 803         <refsect1>
 804                 <title>See Also</title>
 805                 <para>
 806                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 807                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 808                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 809                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 810                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 811                 </para>
 812         </refsect1>
 813
 814 </refentry>