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