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 properties, limit
 106                                 display to certain properties as
 107                                 specified as argument. If not
 108                                 specified all set properties are
 109                                 shown. The argument should be a
 110                                 property name, such as
 111                                 <literal>MainPID</literal>. If
 112                                 specified more than once all
 113                                 properties with the specified names
 114                                 are shown.</para></listitem>
 115                         </varlistentry>
 116
 117                         <varlistentry>
 118                                 <term><option>--all</option></term>
 119                                 <term><option>-a</option></term>
 120
 121                                 <listitem><para>When listing units,
 122                                 show all units, regardless of their
 123                                 state, including inactive units. When
 124                                 showing unit/job/manager properties,
 125                                 show all properties regardless whether
 126                                 they are set or not.</para></listitem>
 127                         </varlistentry>
 128
 129                         <varlistentry>
 130                                 <term><option>--failed</option></term>
 131
 132                                 <listitem><para>When listing units,
 133                                 show only failed units. Do not confuse
 134                                 with
 135                                 <option>--fail</option>.</para></listitem>
 136                         </varlistentry>
 137
 138                         <varlistentry>
 139                                 <term><option>--full</option></term>
 140
 141                                 <listitem><para>Do not ellipsize unit
 142                                 names and truncate unit descriptions
 143                                 in the output of
 144                                 <command>list-units</command> and
 145                                 <command>list-jobs</command>.</para></listitem>
 146                         </varlistentry>
 147
 148                         <varlistentry>
 149                                 <term><option>--fail</option></term>
 150
 151                                 <listitem><para>If the requested
 152                                 operation conflicts with a pending
 153                                 unfinished job, fail the command. If
 154                                 this is not specified the requested
 155                                 operation will replace the pending job,
 156                                 if necessary. Do not confuse
 157                                 with
 158                                 <option>--failed</option>.</para></listitem>
 159                         </varlistentry>
 160
 161                         <varlistentry>
 162                                 <term><option>--ignore-dependencies</option></term>
 163
 164                                 <listitem><para>When enqueuing a new
 165                                 job ignore all its dependencies and
 166                                 execute it immediately. If passed no
 167                                 required units of the unit passed will
 168                                 be pulled in, and no ordering
 169                                 dependencies will be honoured. This is
 170                                 mostly a debugging and rescue tool for
 171                                 the administrator and should not be
 172                                 used by
 173                                 applications.</para></listitem>
 174                         </varlistentry>
 175
 176                         <varlistentry>
 177                                 <term><option>--quiet</option></term>
 178                                 <term><option>-q</option></term>
 179
 180                                 <listitem><para>Suppress output to
 181                                 STDOUT in
 182                                 <command>snapshot</command>,
 183                                 <command>is-active</command>,
 184                                 <command>enable</command> and
 185                                 <command>disable</command>.</para></listitem>
 186                         </varlistentry>
 187
 188                         <varlistentry>
 189                                 <term><option>--no-block</option></term>
 190
 191                                 <listitem><para>Do not synchronously wait for
 192                                 the requested operation to finish. If this is
 193                                 not specified the job will be verified,
 194                                 enqueued and <command>systemctl</command> will
 195                                 wait until it is completed. By passing this
 196                                 argument it is only verified and
 197                                 enqueued.</para></listitem>
 198                         </varlistentry>
 199
 200                         <varlistentry>
 201                                 <term><option>--no-pager</option></term>
 202
 203                                 <listitem><para>Do not pipe output into a
 204                                 pager.</para></listitem>
 205                         </varlistentry>
 206
 207                         <varlistentry>
 208                                 <term><option>--system</option></term>
 209
 210                                 <listitem><para>Talk to the systemd
 211                                 system manager. (Default)</para></listitem>
 212                         </varlistentry>
 213
 214                         <varlistentry>
 215                                 <term><option>--user</option></term>
 216
 217                                 <listitem><para>Talk to the systemd
 218                                 manager of the calling user.</para></listitem>
 219                         </varlistentry>
 220
 221                         <varlistentry>
 222                                 <term><option>--order</option></term>
 223                                 <term><option>--require</option></term>
 224
 225                                 <listitem><para>When used in
 226                                 conjunction with the
 227                                 <command>dot</command> command (see
 228                                 below), selects which dependencies are
 229                                 shown in the dependency graph. If
 230                                 <option>--order</option> is passed
 231                                 only dependencies of type
 232                                 <varname>After=</varname> or
 233                                 <varname>Before=</varname> are
 234                                 shown. If <option>--require</option>
 235                                 is passed only dependencies of type
 236                                 <varname>Requires=</varname>,
 237                                 <varname>RequiresOverridable=</varname>,
 238                                 <varname>Requisite=</varname>,
 239                                 <varname>RequisiteOverridable=</varname>,
 240                                 <varname>Wants=</varname> and
 241                                 <varname>Conflicts=</varname> are
 242                                 shown. If neither is passed, shows
 243                                 dependencies of all these
 244                                 types.</para></listitem>
 245                         </varlistentry>
 246
 247                         <varlistentry>
 248                                 <term><option>--no-wall</option></term>
 249
 250                                 <listitem><para>Don't send wall
 251                                 message before
 252                                 halt, power-off, reboot.</para></listitem>
 253                         </varlistentry>
 254
 255                         <varlistentry>
 256                                 <term><option>--global</option></term>
 257
 258                                 <listitem><para>When used with
 259                                 <command>enable</command> and
 260                                 <command>disable</command>, operate on the
 261                                 global user configuration
 262                                 directory, thus enabling or disabling
 263                                 a unit file globally for all future
 264                                 logins of all users.</para></listitem>
 265                         </varlistentry>
 266
 267                         <varlistentry>
 268                                 <term><option>--no-reload</option></term>
 269
 270                                 <listitem><para>When used with
 271                                 <command>enable</command> and
 272                                 <command>disable</command>, do not
 273                                 implicitly reload daemon configuration
 274                                 after executing the
 275                                 changes.</para></listitem>
 276                         </varlistentry>
 277
 278                         <varlistentry>
 279                                 <term><option>--no-ask-password</option></term>
 280
 281                                 <listitem><para>When used with
 282                                 <command>start</command> and related
 283                                 commands, disables asking for
 284                                 passwords. Background services may
 285                                 require input of a password or
 286                                 passphrase string, for example to
 287                                 unlock system hard disks or
 288                                 cryptographic certificates. Unless
 289                                 this option is specified and the
 290                                 command is invoked from a terminal
 291                                 <command>systemctl</command> will
 292                                 query the user on the terminal for the
 293                                 necessary secrets. Use this option to
 294                                 switch this behavior off. In this
 295                                 case the password must be supplied by
 296                                 some other means (for example
 297                                 graphical password agents) or the
 298                                 service might fail.</para></listitem>
 299                         </varlistentry>
 300
 301                         <varlistentry>
 302                                 <term><option>--kill-who=</option></term>
 303
 304                                 <listitem><para>When used with
 305                                 <command>kill</command>, choose which
 306                                 processes to kill. Must be one of
 307                                 <option>main</option>,
 308                                 <option>control</option> or
 309                                 <option>all</option> to select whether
 310                                 to kill only the main process of the
 311                                 unit, the control process or all
 312                                 processes of the unit. If omitted
 313                                 defaults to
 314                                 <option>all</option>.</para></listitem>
 315                         </varlistentry>
 316
 317                         <varlistentry>
 318                                 <term><option>--signal=</option></term>
 319                                 <term><option>-s</option></term>
 320
 321                                 <listitem><para>When used with
 322                                 <command>kill</command>, choose which
 323                                 signal to send to selected
 324                                 processes. Must be one of the well
 325                                 known signal specifiers such as
 326                                 SIGTERM, SIGINT or SIGSTOP. If
 327                                 omitted defaults to
 328                                 <option>SIGTERM</option>.</para></listitem>
 329                         </varlistentry>
 330
 331                         <varlistentry>
 332                                 <term><option>--force</option></term>
 333                                 <term><option>-f</option></term>
 334
 335                                 <listitem><para>When used with
 336                                 <command>enable</command>, override any
 337                                 existing conflicting
 338                                 symlinks.</para></listitem>
 339
 340                                 <listitem><para>When used with
 341                                 <command>halt</command>,
 342                                 <command>poweroff</command>,
 343                                 <command>reboot</command> or
 344                                 <command>kexec</command> execute
 345                                 selected operation without shutting
 346                                 down all units. However, all processes
 347                                 will be killed forcibly and all file
 348                                 systems are unmounted or remounted
 349                                 read-only. This is hence a drastic but
 350                                 relatively safe option to request an
 351                                 immediate reboot.</para></listitem>
 352                         </varlistentry>
 353
 354                         <varlistentry>
 355                                 <term><option>--defaults</option></term>
 356
 357                                 <listitem><para>When used with
 358                                 <command>disable</command>, ensures
 359                                 that only the symlinks created by
 360                                 <command>enable</command> are removed,
 361                                 not all symlinks pointing to the unit
 362                                 file that shall be
 363                                 disabled.</para></listitem>
 364                         </varlistentry>
 365
 366                         <varlistentry>
 367                                 <term><option>--root=</option></term>
 368
 369                                 <listitem><para>When used with
 370                                 <command>enable</command>/
 371                                 <command>disable</command>/
 372                                 <command>is-enabled</command>,
 373                                 use alternative root path for systemd
 374                                 install.</para></listitem>
 375                         </varlistentry>
 376
 377                         <varlistentry>
 378                                 <term><option>-H</option></term>
 379                                 <term><option>--host</option></term>
 380
 381                                 <listitem><para>Execute operation
 382                                 remotely. Specify a hostname, or
 383                                 username and hostname separated by @,
 384                                 to connect to. This will use SSH to
 385                                 talk to the remote systemd
 386                                 instance.</para></listitem>
 387                         </varlistentry>
 388
 389                         <varlistentry>
 390                                 <term><option>-P</option></term>
 391                                 <term><option>--privileged</option></term>
 392
 393                                 <listitem><para>Acquire privileges via
 394                                 PolicyKit before executing the
 395                                 operation.</para></listitem>
 396                         </varlistentry>
 397                 </variablelist>
 398
 399                 <para>The following commands are understood:</para>
 400
 401                 <variablelist>
 402                         <varlistentry>
 403                                 <term><command>list-units</command></term>
 404
 405                                 <listitem><para>List known units.</para></listitem>
 406                         </varlistentry>
 407                         <varlistentry>
 408                                 <term><command>start [NAME...]</command></term>
 409
 410                                 <listitem><para>Start (activate) one
 411                                 or more units specified on the command
 412                                 line.</para></listitem>
 413                         </varlistentry>
 414                         <varlistentry>
 415                                 <term><command>stop [NAME...]</command></term>
 416
 417                                 <listitem><para>Stop (deactivate) one
 418                                 or more units specified on the command
 419                                 line.</para></listitem>
 420                         </varlistentry>
 421                         <varlistentry>
 422                                 <term><command>reload [NAME...]</command></term>
 423
 424                                 <listitem><para>Asks all units listed
 425                                 on the command line to reload their
 426                                 configuration. Note that this will
 427                                 reload the service-specific
 428                                 configuration, not the unit
 429                                 configuration file of systemd. If you
 430                                 want systemd to reload the
 431                                 configuration file of a unit use the
 432                                 <command>daemon-reload</command>
 433                                 command. In other words: for the
 434                                 example case of Apache, this will
 435                                 reload Apache's
 436                                 <filename>httpd.conf</filename> in the
 437                                 web server, not the
 438                                 <filename>apache.service</filename>
 439                                 systemd unit file. </para>
 440
 441                                 <para>This command should not be
 442                                 confused with the
 443                                 <command>daemon-reload</command> or
 444                                 <command>load</command>
 445                                 commands.</para></listitem>
 446
 447                         </varlistentry>
 448                         <varlistentry>
 449                                 <term><command>restart [NAME...]</command></term>
 450
 451                                 <listitem><para>Restart one or more
 452                                 units specified on the command
 453                                 line. If the units are not running yet
 454                                 they will be
 455                                 started.</para></listitem>
 456                         </varlistentry>
 457                         <varlistentry>
 458                                 <term><command>try-restart [NAME...]</command></term>
 459
 460                                 <listitem><para>Restart one or more
 461                                 units specified on the command
 462                                 line if the units are running. Do
 463                                 nothing if units are not running.
 464                                 Note that for compatibility
 465                                 with Red Hat init scripts
 466                                 <command>condrestart</command> is
 467                                 equivalent to this command.</para></listitem>
 468                         </varlistentry>
 469                         <varlistentry>
 470                                 <term><command>reload-or-restart [NAME...]</command></term>
 471
 472                                 <listitem><para>Reload one or more
 473                                 units if they support it. If not,
 474                                 restart them instead. If the units
 475                                 are not running yet they will be
 476                                 started.</para></listitem>
 477                         </varlistentry>
 478                         <varlistentry>
 479                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 480
 481                                 <listitem><para>Reload one or more
 482                                 units if they support it. If not,
 483                                 restart them instead. Do nothing if
 484                                 the units are not running. Note that
 485                                 for compatibility with SysV init
 486                                 scripts
 487                                 <command>force-reload</command> is
 488                                 equivalent to this
 489                                 command.</para></listitem>
 490                         </varlistentry>
 491                         <varlistentry>
 492                                 <term><command>isolate [NAME]</command></term>
 493
 494                                 <listitem><para>Start the unit
 495                                 specified on the command line and its
 496                                 dependencies and stop all others.</para>
 497
 498                                 <para>This is similar to changing the
 499                                 runlevel in a traditional init system. The
 500                                 <command>isolate</command> command will
 501                                 immediately stop processes that are not
 502                                 enabled in the new unit, possibly including
 503                                 the graphical environment or terminal you
 504                                 are currently using.</para>
 505
 506                                 <para>Note that this works only on units
 507                                 where <option>AllowIsolate=</option> is
 508                                 enabled. See
 509                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 510                                 for details.</para></listitem>
 511                         </varlistentry>
 512                         <varlistentry>
 513                                 <term><command>kill [NAME...]</command></term>
 514
 515                                 <listitem><para>Send a signal to one
 516                                 or more processes of the unit. Use
 517                                 <option>--kill-who=</option> to select
 518                                 which process to kill. Use
 519                                 <option>--kill-mode=</option> to
 520                                 select the kill mode and
 521                                 <option>--signal=</option> to select
 522                                 the signal to send.</para></listitem>
 523                         </varlistentry>
 524                         <varlistentry>
 525                                 <term><command>is-active [NAME...]</command></term>
 526
 527                                 <listitem><para>Check whether any of
 528                                 the specified units are active
 529                                 (i.e. running). Returns an exit code
 530                                 0 if at least one is active, non-zero
 531                                 otherwise. Unless
 532                                 <option>--quiet</option> is specified
 533                                 this will also print the current unit
 534                                 state to STDOUT.</para></listitem>
 535                         </varlistentry>
 536                         <varlistentry>
 537                                 <term><command>status [NAME...|PID...]</command></term>
 538
 539                                 <listitem><para>Show terse runtime
 540                                 status information about one or more
 541                                 units. This function is intended to
 542                                 generate human-readable output. If you
 543                                 are looking for computer-parsable
 544                                 output, use <command>show</command>
 545                                 instead. If a PID is passed
 546                                 information about the unit the process
 547                                 of the PID belongs to is
 548                                 shown.</para></listitem>
 549                         </varlistentry>
 550                         <varlistentry>
 551                                 <term><command>show [NAME...|JOB...]</command></term>
 552
 553                                 <listitem><para>Show properties of one
 554                                 or more units, jobs or the manager
 555                                 itself. If no argument is specified
 556                                 properties of the manager will be
 557                                 shown. If a unit name is specified
 558                                 properties of the unit is shown, and
 559                                 if a job id is specified properties of
 560                                 the job is shown. By default, empty
 561                                 properties are suppressed. Use
 562                                 <option>--all</option> to show those
 563                                 too. To select specific properties to
 564                                 show use
 565                                 <option>--property=</option>. This
 566                                 command is intended to be used
 567                                 whenever computer-parsable output is
 568                                 required. Use
 569                                 <command>status</command> if you are
 570                                 looking for formatted human-readable
 571                                 output.</para></listitem>
 572                         </varlistentry>
 573
 574                         <varlistentry>
 575                                 <term><command>reset-failed [NAME...]</command></term>
 576
 577                                 <listitem><para>Reset the
 578                                 '<literal>failed</literal>' state of the
 579                                 specified units, or if no unit name is
 580                                 passed of all units. When a unit fails
 581                                 in some way (i.e. process exiting with
 582                                 non-zero error code, terminating
 583                                 abnormally or timing out) it will
 584                                 automatically enter the
 585                                 '<literal>failed</literal>' state and
 586                                 its exit code and status is recorded
 587                                 for introspection by the administrator
 588                                 until the service is restarted or
 589                                 reset with this
 590                                 command.</para></listitem>
 591                         </varlistentry>
 592
 593                         <varlistentry>
 594                                 <term><command>enable [NAME...]</command></term>
 595
 596                                 <listitem><para>Enable one or more
 597                                 unit files, as specified on the
 598                                 command line. This will create a
 599                                 number of symlinks as encoded in the
 600                                 <literal>[Install]</literal> sections
 601                                 of the unit files. After the symlinks
 602                                 have been created the systemd
 603                                 configuration is reloaded (in a way
 604                                 that is equivalent to
 605                                 <command>daemon-reload</command>) to
 606                                 ensure the changes are taken into
 607                                 account immediately. Note that this
 608                                 does not have the effect that any of
 609                                 the units enabled are also started at
 610                                 the same time. If this is desired a
 611                                 separate <command>start</command>
 612                                 command must be invoked for the
 613                                 unit.</para>
 614
 615                                 <para>This command will
 616                                 print the actions executed. This
 617                                 output may be suppressed by passing
 618                                 <option>--quiet</option>.</para>
 619
 620                                 <para>Note that this operation creates
 621                                 only the suggested symlinks for the
 622                                 units. While this command is the
 623                                 recommended way to manipulate the unit
 624                                 configuration directory, the
 625                                 administrator is free to make
 626                                 additional changes manually, by
 627                                 placing or removing symlinks in the
 628                                 directory. This is particularly useful
 629                                 to create configurations that deviate
 630                                 from the suggested default
 631                                 installation. In this case the
 632                                 administrator must make sure to invoke
 633                                 <command>daemon-reload</command>
 634                                 manually as necessary, to ensure his
 635                                 changes are taken into account.</para>
 636
 637                                 <para>Enabling units should not be
 638                                 confused with starting (activating)
 639                                 units, as done by the
 640                                 <command>start</command>
 641                                 command. Enabling and starting units
 642                                 is orthogonal: units may be enabled
 643                                 without being started and started
 644                                 without being enabled. Enabling simply
 645                                 hooks the unit into various suggested
 646                                 places (for example, so that the unit
 647                                 is automatically started on boot or
 648                                 when a particular kind of hardware is
 649                                 plugged in). Starting actually spawns
 650                                 the daemon process (in case of service
 651                                 units), or binds the socket (in case
 652                                 of socket units), and so
 653                                 on.</para>
 654
 655                                 <para>Depending on whether
 656                                 <option>--system</option>,
 657                                 <option>--user</option> or
 658                                 <option>--global</option> is specified
 659                                 this enables the unit for the system,
 660                                 for the calling user only
 661                                 or for all future logins of all
 662                                 users. Note that in the latter case no
 663                                 systemd daemon configuration is
 664                                 reloaded.</para>
 665                                 </listitem>
 666                         </varlistentry>
 667
 668                         <varlistentry>
 669                                 <term><command>disable [NAME...]</command></term>
 670
 671                                 <listitem><para>Disables one or more
 672                                 units. This removes all symlinks to
 673                                 the specified unit files from the unit
 674                                 configuration directory, and hence
 675                                 undoes the changes made by
 676                                 <command>enable</command>. Note
 677                                 however that this by default removes
 678                                 all symlinks to the unit files
 679                                 (i.e. including manual additions), not
 680                                 just those actually created by
 681                                 <command>enable</command>. If only the
 682                                 symlinks that are suggested by default
 683                                 shall be removed, pass
 684                                 <option>--defaults</option>. This
 685                                 implicitly reloads the systemd daemon
 686                                 configuration after completing the
 687                                 disabling of the units. Note that this
 688                                 command does not implicitly stop the
 689                                 units that is being disabled. If this
 690                                 is desired an additional
 691                                 <command>stop</command>command should
 692                                 be executed afterwards.</para>
 693
 694                                 <para>This command will print the
 695                                 actions executed. This output may be
 696                                 suppressed by passing
 697                                 <option>--quiet</option>.</para>
 698                                 </listitem>
 699
 700                                 <para>This command honors
 701                                 <option>--system</option>,
 702                                 <option>--user</option>,
 703                                 <option>--global</option> in a similar
 704                                 way as
 705                                 <command>enable</command>.</para>
 706                         </varlistentry>
 707
 708                         <varlistentry>
 709                                 <term><command>is-enabled [NAME...]</command></term>
 710
 711                                 <listitem><para>Checks whether any of
 712                                 the specified unit files is enabled
 713                                 (as with
 714                                 <command>enable</command>). Returns an
 715                                 exit code of 0 if at least one is
 716                                 enabled, non-zero
 717                                 otherwise.</para></listitem>
 718                         </varlistentry>
 719
 720                         <varlistentry>
 721                                 <term><command>load [NAME...]</command></term>
 722
 723                                 <listitem><para>Load one or more units
 724                                 specified on the command line. This
 725                                 will simply load their configuration
 726                                 from disk, but not start them. To
 727                                 start them you need to use the
 728                                 <command>start</command> command which
 729                                 will implicitly load a unit that has
 730                                 not been loaded yet. Note that systemd
 731                                 garbage collects loaded units that are
 732                                 not active or referenced by an active
 733                                 unit. This means that units loaded
 734                                 this way will usually not stay loaded
 735                                 for long. Also note that this command
 736                                 cannot be used to reload unit
 737                                 configuration. Use the
 738                                 <command>daemon-reload</command>
 739                                 command for that. All in all, this
 740                                 command is of little use except for
 741                                 debugging.</para>
 742                                 <para>This command should not be
 743                                 confused with the
 744                                 <command>daemon-reload</command> or
 745                                 <command>reload</command>
 746                                 commands.</para></listitem>
 747                         </varlistentry>
 748                         <varlistentry>
 749                                 <term><command>list-jobs</command></term>
 750
 751                                 <listitem><para>List jobs that are in progress.</para></listitem>
 752                         </varlistentry>
 753                         <varlistentry>
 754                                 <term><command>cancel [JOB...]</command></term>
 755
 756                                 <listitem><para>Cancel one or more
 757                                 jobs specified on the command line by
 758                                 their numeric job
 759                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 760                         </varlistentry>
 761                         <varlistentry>
 762                                 <term><command>monitor</command></term>
 763
 764                                 <listitem><para>Monitor unit/job
 765                                 changes. This is mostly useful for
 766                                 debugging purposes and prints a line
 767                                 each time systemd loads or unloads a
 768                                 unit configuration file, or a unit
 769                                 property changes.</para></listitem>
 770                         </varlistentry>
 771                         <varlistentry>
 772                                 <term><command>dump</command></term>
 773
 774                                 <listitem><para>Dump server
 775                                 status. This will output a (usually
 776                                 very long) human readable manager
 777                                 status dump. Its format is subject to
 778                                 change without notice and should not
 779                                 be parsed by
 780                                 applications.</para></listitem>
 781                         </varlistentry>
 782                         <varlistentry>
 783                                 <term><command>dot</command></term>
 784
 785                                 <listitem><para>Generate textual
 786                                 dependency graph description in dot
 787                                 format for further processing with the
 788                                 GraphViz
 789                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 790                                 tool. Use a command line like
 791                                 <command>systemctl dot | dot -Tsvg >
 792                                 systemd.svg</command> to generate a
 793                                 graphical dependency tree. Unless
 794                                 <option>--order</option> or
 795                                 <option>--require</option> is passed
 796                                 the generated graph will show both
 797                                 ordering and requirement
 798                                 dependencies.</para></listitem>
 799                         </varlistentry>
 800                         <varlistentry>
 801                                 <term><command>snapshot [NAME]</command></term>
 802
 803                                 <listitem><para>Create a snapshot. If
 804                                 a snapshot name is specified, the new
 805                                 snapshot will be named after it. If
 806                                 none is specified an automatic
 807                                 snapshot name is generated. In either
 808                                 case, the snapshot name used is
 809                                 printed to STDOUT, unless
 810                                 <option>--quiet</option> is
 811                                 specified.</para>
 812
 813                                 <para>A snapshot refers to a saved
 814                                 state of the systemd manager. It is
 815                                 implemented itself as a unit that is
 816                                 generated dynamically with this
 817                                 command and has dependencies on all
 818                                 units active at the time. At a later
 819                                 time the user may return to this state
 820                                 by using the
 821                                 <command>isolate</command> command on
 822                                 the snapshot unit.</para></listitem>
 823
 824                                 <para>Snapshots are only useful for
 825                                 saving and restoring which units are
 826                                 running or are stopped, they do not
 827                                 save/restore any other
 828                                 state. Snapshots are dynamic and lost
 829                                 on reboot.</para>
 830                         </varlistentry>
 831                         <varlistentry>
 832                                 <term><command>delete [NAME...]</command></term>
 833
 834                                 <listitem><para>Remove a snapshot
 835                                 previously created with
 836                                 <command>snapshot</command>.</para></listitem>
 837                         </varlistentry>
 838                         <varlistentry>
 839                                 <term><command>daemon-reload</command></term>
 840
 841                                 <listitem><para>Reload systemd manager
 842                                 configuration. This will reload all
 843                                 unit files and recreate the entire
 844                                 dependency tree. While the daemon is
 845                                 reloaded, all sockets systemd listens
 846                                 on on behalf of user configuration will
 847                                 stay accessible.</para> <para>This
 848                                 command should not be confused with
 849                                 the <command>load</command> or
 850                                 <command>reload</command>
 851                                 commands.</para></listitem>
 852                         </varlistentry>
 853                         <varlistentry>
 854                                 <term><command>daemon-reexec</command></term>
 855
 856                                 <listitem><para>Reexecute the systemd
 857                                 manager. This will serialize the
 858                                 manager state, reexecute the process
 859                                 and deserialize the state again. This
 860                                 command is of little use except for
 861                                 debugging and package
 862                                 upgrades. Sometimes it might be
 863                                 helpful as a heavy-weight
 864                                 <command>daemon-reload</command>. While
 865                                 the daemon is reexecuted all sockets
 866                                 systemd listens on on behalf of user
 867                                 configuration will stay
 868                                 accessible.</para></listitem>
 869                         </varlistentry>
 870                         <varlistentry>
 871                                 <term><command>show-environment</command></term>
 872
 873                                 <listitem><para>Dump the systemd
 874                                 manager environment block. The
 875                                 environment block will be dumped in
 876                                 straight-forward form suitable for
 877                                 sourcing into a shell script. This
 878                                 environment block will be passed to
 879                                 all processes the manager
 880                                 spawns.</para></listitem>
 881                         </varlistentry>
 882                         <varlistentry>
 883                                 <term><command>set-environment [NAME=VALUE...]</command></term>
 884
 885                                 <listitem><para>Set one or more
 886                                 systemd manager environment variables,
 887                                 as specified on the command
 888                                 line.</para></listitem>
 889                         </varlistentry>
 890                         <varlistentry>
 891                                 <term><command>unset-environment [NAME...]</command></term>
 892
 893                                 <listitem><para>Unset one or more
 894                                 systemd manager environment
 895                                 variables. If only a variable name is
 896                                 specified it will be removed
 897                                 regardless of its value. If a variable
 898                                 and a value are specified the variable
 899                                 is only removed if it has the
 900                                 specified value.</para></listitem>
 901                         </varlistentry>
 902                         <varlistentry>
 903                                 <term><command>default</command></term>
 904
 905                                 <listitem><para>Enter default
 906                                 mode. This is mostly equivalent to
 907                                 <command>start
 908                                 default.target</command>.</para></listitem>
 909                         </varlistentry>
 910                         <varlistentry>
 911                                 <term><command>rescue</command></term>
 912
 913                                 <listitem><para>Enter rescue
 914                                 mode. This is mostly equivalent to
 915                                 <command>isolate
 916                                 rescue.target</command> but also
 917                                 prints a wall message to all
 918                                 users.</para></listitem>
 919                         </varlistentry>
 920                         <varlistentry>
 921                                 <term><command>emergency</command></term>
 922
 923                                 <listitem><para>Enter emergency
 924                                 mode. This is mostly equivalent to
 925                                 <command>isolate
 926                                 emergency.target</command> but also
 927                                 prints a wall message to all
 928                                 users.</para></listitem>
 929                         </varlistentry>
 930                         <varlistentry>
 931                                 <term><command>halt</command></term>
 932
 933                                 <listitem><para>Shut down and halt the
 934                                 system. This is mostly equivalent to
 935                                 <command>start halt.target</command>
 936                                 but also prints a wall message to all
 937                                 users.  If
 938                                 combined with <option>--force</option>
 939                                 shutdown of all running services is
 940                                 skipped, however all processes are killed
 941                                 and all file systems are unmounted or
 942                                 mounted read-only, immediately
 943                                 followed by the
 944                                 system halt.</para></listitem>
 945                         </varlistentry>
 946                         <varlistentry>
 947                                 <term><command>poweroff</command></term>
 948
 949                                 <listitem><para>Shut down and
 950                                 power-off the system. This is mostly
 951                                 equivalent to <command>start
 952                                 poweroff.target</command> but also
 953                                 prints a wall message to all
 954                                 users. If
 955                                 combined with <option>--force</option>
 956                                 shutdown of all running services is
 957                                 skipped, however all processes are killed
 958                                 and all file systems are unmounted or
 959                                 mounted read-only, immediately
 960                                 followed by the
 961                                 powering off.</para></listitem>
 962                         </varlistentry>
 963                         <varlistentry>
 964                                 <term><command>reboot</command></term>
 965
 966                                 <listitem><para>Shut down and
 967                                 reboot the system. This is mostly
 968                                 equivalent to <command>start
 969                                 reboot.target</command> but also
 970                                 prints a wall message to all
 971                                 users. If
 972                                 combined with <option>--force</option>
 973                                 shutdown of all running services is
 974                                 skipped, however all processes are killed
 975                                 and all file systems are unmounted or
 976                                 mounted read-only, immediately
 977                                 followed by the
 978                                 reboot.</para></listitem>
 979                         </varlistentry>
 980                         <varlistentry>
 981                                 <term><command>kexec</command></term>
 982
 983                                 <listitem><para>Shut down and reboot
 984                                 the system via kexec. This is mostly
 985                                 equivalent to <command>start
 986                                 kexec.target</command> but also prints
 987                                 a wall message to all users. If
 988                                 combined with <option>--force</option>
 989                                 shutdown of all running services is
 990                                 skipped, however all processes are killed
 991                                 and all file systems are unmounted or
 992                                 mounted read-only, immediately
 993                                 followed by the
 994                                 reboot.</para></listitem>
 995                         </varlistentry>
 996                         <varlistentry>
 997                                 <term><command>exit</command></term>
 998
 999                                 <listitem><para>Ask the systemd
1000                                 manager to quit. This is only
1001                                 supported for user service managers
1002                                 (i.e. in conjunction with the
1003                                 <option>--user</option> option) and
1004                                 will fail otherwise.</para></listitem>
1005                         </varlistentry>
1006                 </variablelist>
1007
1008         </refsect1>
1009
1010         <refsect1>
1011                 <title>Exit status</title>
1012
1013                 <para>On success 0 is returned, a non-zero failure
1014                 code otherwise.</para>
1015         </refsect1>
1016
1017         <refsect1>
1018                 <title>Environment</title>
1019
1020                 <variablelist>
1021                         <varlistentry>
1022                                 <term><varname>$SYSTEMD_PAGER</varname></term>
1023                                 <listitem><para>Pager to use when
1024                                 <option>--no-pager</option> is not given;
1025                                 overrides <varname>$PAGER</varname>.  Setting
1026                                 this to an empty string or the value
1027                                 <literal>cat</literal> is equivalent to passing
1028                                 <option>--no-pager</option>.</para></listitem>
1029                         </varlistentry>
1030                 </variablelist>
1031         </refsect1>
1032
1033         <refsect1>
1034                 <title>See Also</title>
1035                 <para>
1036                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1037                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1038                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1039                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1040                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
1041                 </para>
1042         </refsect1>
1043
1044 </refentry>