man/systemctl.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   6   This file is part of systemd.
   7
   8   Copyright 2010 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU General Public License as published by
  12   the Free Software Foundation; either version 2 of the License, or
  13   (at your option) any later version.
  14
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  18   General Public License for more details.
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  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-who=</option></term>
 302
 303                                 <listitem><para>When used with
 304                                 <command>kill</command>, choose which
 305                                 processes to kill. Must be one of
 306                                 <option>main</option>,
 307                                 <option>control</option> or
 308                                 <option>all</option> to select whether
 309                                 to kill only the main process of the
 310                                 unit, the control process or all
 311                                 processes of the unit. If omitted
 312                                 defaults to
 313                                 <option>all</option>.</para></listitem>
 314                         </varlistentry>
 315
 316                         <varlistentry>
 317                                 <term><option>--signal=</option></term>
 318                                 <term><option>-s</option></term>
 319
 320                                 <listitem><para>When used with
 321                                 <command>kill</command>, choose which
 322                                 signal to send to selected
 323                                 processes. Must be one of the well
 324                                 known signal specifiers such as
 325                                 SIGTERM, SIGINT or SIGSTOP. If
 326                                 omitted defaults to
 327                                 <option>SIGTERM</option>.</para></listitem>
 328                         </varlistentry>
 329
 330                         <varlistentry>
 331                                 <term><option>--force</option></term>
 332                                 <term><option>-f</option></term>
 333
 334                                 <listitem><para>When used with
 335                                 <command>enable</command>, override any
 336                                 existing conflicting
 337                                 symlinks.</para></listitem>
 338
 339                                 <listitem><para>When used with
 340                                 <command>halt</command>,
 341                                 <command>poweroff</command>,
 342                                 <command>reboot</command> or
 343                                 <command>kexec</command> execute
 344                                 selected operation without shutting
 345                                 down all units. However, all processes
 346                                 will be killed forcibly and all file
 347                                 systems are unmounted or remounted
 348                                 read-only. This is hence a drastic but
 349                                 relatively safe option to request an
 350                                 immediate reboot.</para></listitem>
 351                         </varlistentry>
 352
 353                         <varlistentry>
 354                                 <term><option>--defaults</option></term>
 355
 356                                 <listitem><para>When used with
 357                                 <command>disable</command>, ensures
 358                                 that only the symlinks created by
 359                                 <command>enable</command> are removed,
 360                                 not all symlinks pointing to the unit
 361                                 file that shall be
 362                                 disabled.</para></listitem>
 363                         </varlistentry>
 364
 365                         <varlistentry>
 366                                 <term><option>--root=</option></term>
 367
 368                                 <listitem><para>When used with
 369                                 <command>enable</command>/
 370                                 <command>disable</command>/
 371                                 <command>is-enabled</command>,
 372                                 use alternative root path for systemd
 373                                 install.</para></listitem>
 374                         </varlistentry>
 375
 376                         <varlistentry>
 377                                 <term><option>-H</option></term>
 378                                 <term><option>--host</option></term>
 379
 380                                 <listitem><para>Execute operation
 381                                 remotely. Specify a hostname, or
 382                                 username and hostname separated by @,
 383                                 to connect to. This will use SSH to
 384                                 talk to the remote systemd
 385                                 instance.</para></listitem>
 386                         </varlistentry>
 387
 388                         <varlistentry>
 389                                 <term><option>-P</option></term>
 390                                 <term><option>--privileged</option></term>
 391
 392                                 <listitem><para>Acquire privileges via
 393                                 PolicyKit before executing the
 394                                 operation.</para></listitem>
 395                         </varlistentry>
 396                 </variablelist>
 397
 398                 <para>The following commands are understood:</para>
 399
 400                 <variablelist>
 401                         <varlistentry>
 402                                 <term><command>list-units</command></term>
 403
 404                                 <listitem><para>List known units.</para></listitem>
 405                         </varlistentry>
 406                         <varlistentry>
 407                                 <term><command>start [NAME...]</command></term>
 408
 409                                 <listitem><para>Start (activate) one
 410                                 or more units specified on the command
 411                                 line.</para></listitem>
 412                         </varlistentry>
 413                         <varlistentry>
 414                                 <term><command>stop [NAME...]</command></term>
 415
 416                                 <listitem><para>Stop (deactivate) one
 417                                 or more units specified on the command
 418                                 line.</para></listitem>
 419                         </varlistentry>
 420                         <varlistentry>
 421                                 <term><command>reload [NAME...]</command></term>
 422
 423                                 <listitem><para>Asks all units listed
 424                                 on the command line to reload their
 425                                 configuration. Note that this will
 426                                 reload the service-specific
 427                                 configuration, not the unit
 428                                 configuration file of systemd. If you
 429                                 want systemd to reload the
 430                                 configuration file of a unit use the
 431                                 <command>daemon-reload</command>
 432                                 command. In other words: for the
 433                                 example case of Apache, this will
 434                                 reload Apache's
 435                                 <filename>httpd.conf</filename> in the
 436                                 web server, not the
 437                                 <filename>apache.service</filename>
 438                                 systemd unit file. </para>
 439
 440                                 <para>This command should not be
 441                                 confused with the
 442                                 <command>daemon-reload</command> or
 443                                 <command>load</command>
 444                                 commands.</para></listitem>
 445
 446                         </varlistentry>
 447                         <varlistentry>
 448                                 <term><command>restart [NAME...]</command></term>
 449
 450                                 <listitem><para>Restart one or more
 451                                 units specified on the command
 452                                 line. If the units are not running yet
 453                                 they will be
 454                                 started.</para></listitem>
 455                         </varlistentry>
 456                         <varlistentry>
 457                                 <term><command>try-restart [NAME...]</command></term>
 458
 459                                 <listitem><para>Restart one or more
 460                                 units specified on the command
 461                                 line if the units are running. Do
 462                                 nothing if units are not running.
 463                                 Note that for compatibility
 464                                 with Red Hat init scripts
 465                                 <command>condrestart</command> is
 466                                 equivalent to this command.</para></listitem>
 467                         </varlistentry>
 468                         <varlistentry>
 469                                 <term><command>reload-or-restart [NAME...]</command></term>
 470
 471                                 <listitem><para>Reload one or more
 472                                 units if they support it. If not,
 473                                 restart them instead. If the units
 474                                 are not running yet they will be
 475                                 started.</para></listitem>
 476                         </varlistentry>
 477                         <varlistentry>
 478                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 479
 480                                 <listitem><para>Reload one or more
 481                                 units if they support it. If not,
 482                                 restart them instead. Do nothing if
 483                                 the units are not running. Note that
 484                                 for compatibility with SysV init
 485                                 scripts
 486                                 <command>force-reload</command> is
 487                                 equivalent to this
 488                                 command.</para></listitem>
 489                         </varlistentry>
 490                         <varlistentry>
 491                                 <term><command>isolate [NAME]</command></term>
 492
 493                                 <listitem><para>Start the unit
 494                                 specified on the command line and its
 495                                 dependencies and stop all others.</para>
 496
 497                                 <para>This is similar to changing the
 498                                 runlevel in a traditional init system. The
 499                                 <command>isolate</command> command will
 500                                 immediately stop processes that are not
 501                                 enabled in the new unit, possibly including
 502                                 the graphical environment or terminal you
 503                                 are currently using.</para>
 504
 505                                 <para>Note that this works only on units
 506                                 where <option>AllowIsolate=</option> is
 507                                 enabled. See
 508                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 509                                 for details.</para></listitem>
 510                         </varlistentry>
 511                         <varlistentry>
 512                                 <term><command>kill [NAME...]</command></term>
 513
 514                                 <listitem><para>Send a signal to one
 515                                 or more processes of the unit. Use
 516                                 <option>--kill-who=</option> to select
 517                                 which process to kill. Use
 518                                 <option>--kill-mode=</option> to
 519                                 select the kill mode and
 520                                 <option>--signal=</option> to select
 521                                 the signal to send.</para></listitem>
 522                         </varlistentry>
 523                         <varlistentry>
 524                                 <term><command>is-active [NAME...]</command></term>
 525
 526                                 <listitem><para>Check whether any of
 527                                 the specified units are active
 528                                 (i.e. running). Returns an exit code
 529                                 0 if at least one is active, non-zero
 530                                 otherwise. Unless
 531                                 <option>--quiet</option> is specified
 532                                 this will also print the current unit
 533                                 state to STDOUT.</para></listitem>
 534                         </varlistentry>
 535                         <varlistentry>
 536                                 <term><command>status [NAME...|PID...]</command></term>
 537
 538                                 <listitem><para>Show terse runtime
 539                                 status information about one or more
 540                                 units. This function is intended to
 541                                 generate human-readable output. If you
 542                                 are looking for computer-parsable
 543                                 output, use <command>show</command>
 544                                 instead. If a PID is passed
 545                                 information about the unit the process
 546                                 of the PID belongs to is
 547                                 shown.</para></listitem>
 548                         </varlistentry>
 549                         <varlistentry>
 550                                 <term><command>show [NAME...|JOB...]</command></term>
 551
 552                                 <listitem><para>Show properties of one
 553                                 or more units, jobs or the manager
 554                                 itself. If no argument is specified
 555                                 properties of the manager will be
 556                                 shown. If a unit name is specified
 557                                 properties of the unit is shown, and
 558                                 if a job id is specified properties of
 559                                 the job is shown. By default, empty
 560                                 properties are suppressed. Use
 561                                 <option>--all</option> to show those
 562                                 too. To select specific properties to
 563                                 show use
 564                                 <option>--property=</option>. This
 565                                 command is intended to be used
 566                                 whenever computer-parsable output is
 567                                 required. Use
 568                                 <command>status</command> if you are
 569                                 looking for formatted human-readable
 570                                 output.</para></listitem>
 571                         </varlistentry>
 572
 573                         <varlistentry>
 574                                 <term><command>reset-failed [NAME...]</command></term>
 575
 576                                 <listitem><para>Reset the
 577                                 '<literal>failed</literal>' state of the
 578                                 specified units, or if no unit name is
 579                                 passed of all units. When a unit fails
 580                                 in some way (i.e. process exiting with
 581                                 non-zero error code, terminating
 582                                 abnormally or timing out) it will
 583                                 automatically enter the
 584                                 '<literal>failed</literal>' state and
 585                                 its exit code and status is recorded
 586                                 for introspection by the administrator
 587                                 until the service is restarted or
 588                                 reset with this
 589                                 command.</para></listitem>
 590                         </varlistentry>
 591
 592                         <varlistentry>
 593                                 <term><command>enable [NAME...]</command></term>
 594
 595                                 <listitem><para>Enable one or more
 596                                 unit files, as specified on the
 597                                 command line. This will create a
 598                                 number of symlinks as encoded in the
 599                                 <literal>[Install]</literal> sections
 600                                 of the unit files. After the symlinks
 601                                 have been created the systemd
 602                                 configuration is reloaded (in a way
 603                                 that is equivalent to
 604                                 <command>daemon-reload</command>) to
 605                                 ensure the changes are taken into
 606                                 account immediately. Note that this
 607                                 does not have the effect that any of
 608                                 the units enabled are also started at
 609                                 the same time. If this is desired a
 610                                 separate <command>start</command>
 611                                 command must be invoked for the
 612                                 unit.</para>
 613
 614                                 <para>This command will
 615                                 print the actions executed. This
 616                                 output may be suppressed by passing
 617                                 <option>--quiet</option>.</para>
 618
 619                                 <para>Note that this operation creates
 620                                 only the suggested symlinks for the
 621                                 units. While this command is the
 622                                 recommended way to manipulate the unit
 623                                 configuration directory, the
 624                                 administrator is free to make
 625                                 additional changes manually, by
 626                                 placing or removing symlinks in the
 627                                 directory. This is particularly useful
 628                                 to create configurations that deviate
 629                                 from the suggested default
 630                                 installation. In this case the
 631                                 administrator must make sure to invoke
 632                                 <command>daemon-reload</command>
 633                                 manually as necessary, to ensure his
 634                                 changes are taken into account.</para>
 635
 636                                 <para>Enabling units should not be
 637                                 confused with starting (activating)
 638                                 units, as done by the
 639                                 <command>start</command>
 640                                 command. Enabling and starting units
 641                                 is orthogonal: units may be enabled
 642                                 without being started and started
 643                                 without being enabled. Enabling simply
 644                                 hooks the unit into various suggested
 645                                 places (for example, so that the unit
 646                                 is automatically started on boot or
 647                                 when a particular kind of hardware is
 648                                 plugged in). Starting actually spawns
 649                                 the daemon process (in case of service
 650                                 units), or binds the socket (in case
 651                                 of socket units), and so
 652                                 on.</para>
 653
 654                                 <para>Depending on whether
 655                                 <option>--system</option>,
 656                                 <option>--user</option> or
 657                                 <option>--global</option> is specified
 658                                 this enables the unit for the system,
 659                                 for the calling user only
 660                                 or for all future logins of all
 661                                 users. Note that in the latter case no
 662                                 systemd daemon configuration is
 663                                 reloaded.</para>
 664                                 </listitem>
 665                         </varlistentry>
 666
 667                         <varlistentry>
 668                                 <term><command>disable [NAME...]</command></term>
 669
 670                                 <listitem><para>Disables one or more
 671                                 units. This removes all symlinks to
 672                                 the specified unit files from the unit
 673                                 configuration directory, and hence
 674                                 undoes the changes made by
 675                                 <command>enable</command>. Note
 676                                 however that this by default removes
 677                                 all symlinks to the unit files
 678                                 (i.e. including manual additions), not
 679                                 just those actually created by
 680                                 <command>enable</command>. If only the
 681                                 symlinks that are suggested by default
 682                                 shall be removed, pass
 683                                 <option>--defaults</option>. This
 684                                 implicitly reloads the systemd daemon
 685                                 configuration after completing the
 686                                 disabling of the units. Note that this
 687                                 command does not implicitly stop the
 688                                 units that is being disabled. If this
 689                                 is desired an additional
 690                                 <command>stop</command>command should
 691                                 be executed afterwards.</para>
 692
 693                                 <para>This command will print the
 694                                 actions executed. This output may be
 695                                 suppressed by passing
 696                                 <option>--quiet</option>.</para>
 697                                 </listitem>
 698
 699                                 <para>This command honors
 700                                 <option>--system</option>,
 701                                 <option>--user</option>,
 702                                 <option>--global</option> in a similar
 703                                 way as
 704                                 <command>enable</command>.</para>
 705                         </varlistentry>
 706
 707                         <varlistentry>
 708                                 <term><command>is-enabled [NAME...]</command></term>
 709
 710                                 <listitem><para>Checks whether any of
 711                                 the specified unit files is enabled
 712                                 (as with
 713                                 <command>enable</command>). Returns an
 714                                 exit code of 0 if at least one is
 715                                 enabled, non-zero
 716                                 otherwise.</para></listitem>
 717                         </varlistentry>
 718
 719                         <varlistentry>
 720                                 <term><command>load [NAME...]</command></term>
 721
 722                                 <listitem><para>Load one or more units
 723                                 specified on the command line. This
 724                                 will simply load their configuration
 725                                 from disk, but not start them. To
 726                                 start them you need to use the
 727                                 <command>start</command> command which
 728                                 will implicitly load a unit that has
 729                                 not been loaded yet. Note that systemd
 730                                 garbage collects loaded units that are
 731                                 not active or referenced by an active
 732                                 unit. This means that units loaded
 733                                 this way will usually not stay loaded
 734                                 for long. Also note that this command
 735                                 cannot be used to reload unit
 736                                 configuration. Use the
 737                                 <command>daemon-reload</command>
 738                                 command for that. All in all, this
 739                                 command is of little use except for
 740                                 debugging.</para>
 741                                 <para>This command should not be
 742                                 confused with the
 743                                 <command>daemon-reload</command> or
 744                                 <command>reload</command>
 745                                 commands.</para></listitem>
 746                         </varlistentry>
 747                         <varlistentry>
 748                                 <term><command>list-jobs</command></term>
 749
 750                                 <listitem><para>List jobs that are in progress.</para></listitem>
 751                         </varlistentry>
 752                         <varlistentry>
 753                                 <term><command>cancel [JOB...]</command></term>
 754
 755                                 <listitem><para>Cancel one or more
 756                                 jobs specified on the command line by
 757                                 their numeric job
 758                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 759                         </varlistentry>
 760                         <varlistentry>
 761                                 <term><command>monitor</command></term>
 762
 763                                 <listitem><para>Monitor unit/job
 764                                 changes. This is mostly useful for
 765                                 debugging purposes and prints a line
 766                                 each time systemd loads or unloads a
 767                                 unit configuration file, or a unit
 768                                 property changes.</para></listitem>
 769                         </varlistentry>
 770                         <varlistentry>
 771                                 <term><command>dump</command></term>
 772
 773                                 <listitem><para>Dump server
 774                                 status. This will output a (usually
 775                                 very long) human readable manager
 776                                 status dump. Its format is subject to
 777                                 change without notice and should not
 778                                 be parsed by
 779                                 applications.</para></listitem>
 780                         </varlistentry>
 781                         <varlistentry>
 782                                 <term><command>dot</command></term>
 783
 784                                 <listitem><para>Generate textual
 785                                 dependency graph description in dot
 786                                 format for further processing with the
 787                                 GraphViz
 788                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 789                                 tool. Use a command line like
 790                                 <command>systemctl dot | dot -Tsvg >
 791                                 systemd.svg</command> to generate a
 792                                 graphical dependency tree. Unless
 793                                 <option>--order</option> or
 794                                 <option>--require</option> is passed
 795                                 the generated graph will show both
 796                                 ordering and requirement
 797                                 dependencies.</para></listitem>
 798                         </varlistentry>
 799                         <varlistentry>
 800                                 <term><command>snapshot [NAME]</command></term>
 801
 802                                 <listitem><para>Create a snapshot. If
 803                                 a snapshot name is specified, the new
 804                                 snapshot will be named after it. If
 805                                 none is specified an automatic
 806                                 snapshot name is generated. In either
 807                                 case, the snapshot name used is
 808                                 printed to STDOUT, unless
 809                                 <option>--quiet</option> is
 810                                 specified.</para>
 811
 812                                 <para>A snapshot refers to a saved
 813                                 state of the systemd manager. It is
 814                                 implemented itself as a unit that is
 815                                 generated dynamically with this
 816                                 command and has dependencies on all
 817                                 units active at the time. At a later
 818                                 time the user may return to this state
 819                                 by using the
 820                                 <command>isolate</command> command on
 821                                 the snapshot unit.</para></listitem>
 822
 823                                 <para>Snapshots are only useful for
 824                                 saving and restoring which units are
 825                                 running or are stopped, they do not
 826                                 save/restore any other
 827                                 state. Snapshots are dynamic and lost
 828                                 on reboot.</para>
 829                         </varlistentry>
 830                         <varlistentry>
 831                                 <term><command>delete [NAME...]</command></term>
 832
 833                                 <listitem><para>Remove a snapshot
 834                                 previously created with
 835                                 <command>snapshot</command>.</para></listitem>
 836                         </varlistentry>
 837                         <varlistentry>
 838                                 <term><command>daemon-reload</command></term>
 839
 840                                 <listitem><para>Reload systemd manager
 841                                 configuration. This will reload all
 842                                 unit files and recreate the entire
 843                                 dependency tree. While the daemon is
 844                                 reloaded, all sockets systemd listens
 845                                 on on behalf of user configuration will
 846                                 stay accessible.</para> <para>This
 847                                 command should not be confused with
 848                                 the <command>load</command> or
 849                                 <command>reload</command>
 850                                 commands.</para></listitem>
 851                         </varlistentry>
 852                         <varlistentry>
 853                                 <term><command>daemon-reexec</command></term>
 854
 855                                 <listitem><para>Reexecute the systemd
 856                                 manager. This will serialize the
 857                                 manager state, reexecute the process
 858                                 and deserialize the state again. This
 859                                 command is of little use except for
 860                                 debugging and package
 861                                 upgrades. Sometimes it might be
 862                                 helpful as a heavy-weight
 863                                 <command>daemon-reload</command>. While
 864                                 the daemon is reexecuted all sockets
 865                                 systemd listens on on behalf of user
 866                                 configuration will stay
 867                                 accessible.</para></listitem>
 868                         </varlistentry>
 869                         <varlistentry>
 870                                 <term><command>show-environment</command></term>
 871
 872                                 <listitem><para>Dump the systemd
 873                                 manager environment block. The
 874                                 environment block will be dumped in
 875                                 straight-forward form suitable for
 876                                 sourcing into a shell script. This
 877                                 environment block will be passed to
 878                                 all processes the manager
 879                                 spawns.</para></listitem>
 880                         </varlistentry>
 881                         <varlistentry>
 882                                 <term><command>set-environment [NAME=VALUE...]</command></term>
 883
 884                                 <listitem><para>Set one or more
 885                                 systemd manager environment variables,
 886                                 as specified on the command
 887                                 line.</para></listitem>
 888                         </varlistentry>
 889                         <varlistentry>
 890                                 <term><command>unset-environment [NAME...]</command></term>
 891
 892                                 <listitem><para>Unset one or more
 893                                 systemd manager environment
 894                                 variables. If only a variable name is
 895                                 specified it will be removed
 896                                 regardless of its value. If a variable
 897                                 and a value are specified the variable
 898                                 is only removed if it has the
 899                                 specified value.</para></listitem>
 900                         </varlistentry>
 901                         <varlistentry>
 902                                 <term><command>default</command></term>
 903
 904                                 <listitem><para>Enter default
 905                                 mode. This is mostly equivalent to
 906                                 <command>start
 907                                 default.target</command>.</para></listitem>
 908                         </varlistentry>
 909                         <varlistentry>
 910                                 <term><command>rescue</command></term>
 911
 912                                 <listitem><para>Enter rescue
 913                                 mode. This is mostly equivalent to
 914                                 <command>isolate
 915                                 rescue.target</command> but also
 916                                 prints a wall message to all
 917                                 users.</para></listitem>
 918                         </varlistentry>
 919                         <varlistentry>
 920                                 <term><command>emergency</command></term>
 921
 922                                 <listitem><para>Enter emergency
 923                                 mode. This is mostly equivalent to
 924                                 <command>isolate
 925                                 emergency.target</command> but also
 926                                 prints a wall message to all
 927                                 users.</para></listitem>
 928                         </varlistentry>
 929                         <varlistentry>
 930                                 <term><command>halt</command></term>
 931
 932                                 <listitem><para>Shut down and halt the
 933                                 system. This is mostly equivalent to
 934                                 <command>start halt.target</command>
 935                                 but also prints a wall message to all
 936                                 users.  If
 937                                 combined with <option>--force</option>
 938                                 shutdown of all running services is
 939                                 skipped, however all processes are killed
 940                                 and all file systems are unmounted or
 941                                 mounted read-only, immediately
 942                                 followed by the
 943                                 system halt.</para></listitem>
 944                         </varlistentry>
 945                         <varlistentry>
 946                                 <term><command>poweroff</command></term>
 947
 948                                 <listitem><para>Shut down and
 949                                 power-off the system. This is mostly
 950                                 equivalent to <command>start
 951                                 poweroff.target</command> but also
 952                                 prints a wall message to all
 953                                 users. If
 954                                 combined with <option>--force</option>
 955                                 shutdown of all running services is
 956                                 skipped, however all processes are killed
 957                                 and all file systems are unmounted or
 958                                 mounted read-only, immediately
 959                                 followed by the
 960                                 powering off.</para></listitem>
 961                         </varlistentry>
 962                         <varlistentry>
 963                                 <term><command>reboot</command></term>
 964
 965                                 <listitem><para>Shut down and
 966                                 reboot the system. This is mostly
 967                                 equivalent to <command>start
 968                                 reboot.target</command> but also
 969                                 prints a wall message to all
 970                                 users. If
 971                                 combined with <option>--force</option>
 972                                 shutdown of all running services is
 973                                 skipped, however all processes are killed
 974                                 and all file systems are unmounted or
 975                                 mounted read-only, immediately
 976                                 followed by the
 977                                 reboot.</para></listitem>
 978                         </varlistentry>
 979                         <varlistentry>
 980                                 <term><command>kexec</command></term>
 981
 982                                 <listitem><para>Shut down and reboot
 983                                 the system via kexec. This is mostly
 984                                 equivalent to <command>start
 985                                 kexec.target</command> but also prints
 986                                 a wall message to all users. If
 987                                 combined with <option>--force</option>
 988                                 shutdown of all running services is
 989                                 skipped, however all processes are killed
 990                                 and all file systems are unmounted or
 991                                 mounted read-only, immediately
 992                                 followed by the
 993                                 reboot.</para></listitem>
 994                         </varlistentry>
 995                         <varlistentry>
 996                                 <term><command>exit</command></term>
 997
 998                                 <listitem><para>Ask the systemd
 999                                 manager to quit. This is only
1000                                 supported for user service managers
1001                                 (i.e. in conjunction with the
1002                                 <option>--user</option> option) and
1003                                 will fail otherwise.</para></listitem>
1004                         </varlistentry>
1005                 </variablelist>
1006
1007         </refsect1>
1008
1009         <refsect1>
1010                 <title>Exit status</title>
1011
1012                 <para>On success 0 is returned, a non-zero failure
1013                 code otherwise.</para>
1014         </refsect1>
1015
1016         <refsect1>
1017                 <title>Environment</title>
1018
1019                 <variablelist>
1020                         <varlistentry>
1021                                 <term><varname>$SYSTEMD_PAGER</varname></term>
1022                                 <listitem><para>Pager to use when
1023                                 <option>--no-pager</option> is not given;
1024                                 overrides <varname>$PAGER</varname>.  Setting
1025                                 this to an empty string or the value
1026                                 <literal>cat</literal> is equivalent to passing
1027                                 <option>--no-pager</option>.</para></listitem>
1028                         </varlistentry>
1029                 </variablelist>
1030         </refsect1>
1031
1032         <refsect1>
1033                 <title>See Also</title>
1034                 <para>
1035                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1036                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1037                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1038                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1039                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
1040                 </para>
1041         </refsect1>
1042
1043 </refentry>