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-legend</option></term>
 202
 203                                 <listitem><para>Do not print a legend, i.e.
 204                                 the column headers and the footer with hints.
 205                                 </para></listitem>
 206                         </varlistentry>
 207
 208                         <varlistentry>
 209                                 <term><option>--no-pager</option></term>
 210
 211                                 <listitem><para>Do not pipe output into a
 212                                 pager.</para></listitem>
 213                         </varlistentry>
 214
 215                         <varlistentry>
 216                                 <term><option>--system</option></term>
 217
 218                                 <listitem><para>Talk to the systemd
 219                                 system manager. (Default)</para></listitem>
 220                         </varlistentry>
 221
 222                         <varlistentry>
 223                                 <term><option>--user</option></term>
 224
 225                                 <listitem><para>Talk to the systemd
 226                                 manager of the calling user.</para></listitem>
 227                         </varlistentry>
 228
 229                         <varlistentry>
 230                                 <term><option>--order</option></term>
 231                                 <term><option>--require</option></term>
 232
 233                                 <listitem><para>When used in
 234                                 conjunction with the
 235                                 <command>dot</command> command (see
 236                                 below), selects which dependencies are
 237                                 shown in the dependency graph. If
 238                                 <option>--order</option> is passed
 239                                 only dependencies of type
 240                                 <varname>After=</varname> or
 241                                 <varname>Before=</varname> are
 242                                 shown. If <option>--require</option>
 243                                 is passed only dependencies of type
 244                                 <varname>Requires=</varname>,
 245                                 <varname>RequiresOverridable=</varname>,
 246                                 <varname>Requisite=</varname>,
 247                                 <varname>RequisiteOverridable=</varname>,
 248                                 <varname>Wants=</varname> and
 249                                 <varname>Conflicts=</varname> are
 250                                 shown. If neither is passed, shows
 251                                 dependencies of all these
 252                                 types.</para></listitem>
 253                         </varlistentry>
 254
 255                         <varlistentry>
 256                                 <term><option>--no-wall</option></term>
 257
 258                                 <listitem><para>Don't send wall
 259                                 message before
 260                                 halt, power-off, reboot.</para></listitem>
 261                         </varlistentry>
 262
 263                         <varlistentry>
 264                                 <term><option>--global</option></term>
 265
 266                                 <listitem><para>When used with
 267                                 <command>enable</command> and
 268                                 <command>disable</command>, operate on the
 269                                 global user configuration
 270                                 directory, thus enabling or disabling
 271                                 a unit file globally for all future
 272                                 logins of all users.</para></listitem>
 273                         </varlistentry>
 274
 275                         <varlistentry>
 276                                 <term><option>--no-reload</option></term>
 277
 278                                 <listitem><para>When used with
 279                                 <command>enable</command> and
 280                                 <command>disable</command>, do not
 281                                 implicitly reload daemon configuration
 282                                 after executing the
 283                                 changes.</para></listitem>
 284                         </varlistentry>
 285
 286                         <varlistentry>
 287                                 <term><option>--no-ask-password</option></term>
 288
 289                                 <listitem><para>When used with
 290                                 <command>start</command> and related
 291                                 commands, disables asking for
 292                                 passwords. Background services may
 293                                 require input of a password or
 294                                 passphrase string, for example to
 295                                 unlock system hard disks or
 296                                 cryptographic certificates. Unless
 297                                 this option is specified and the
 298                                 command is invoked from a terminal
 299                                 <command>systemctl</command> will
 300                                 query the user on the terminal for the
 301                                 necessary secrets. Use this option to
 302                                 switch this behavior off. In this
 303                                 case the password must be supplied by
 304                                 some other means (for example
 305                                 graphical password agents) or the
 306                                 service might fail.</para></listitem>
 307                         </varlistentry>
 308
 309                         <varlistentry>
 310                                 <term><option>--kill-who=</option></term>
 311
 312                                 <listitem><para>When used with
 313                                 <command>kill</command>, choose which
 314                                 processes to kill. Must be one of
 315                                 <option>main</option>,
 316                                 <option>control</option> or
 317                                 <option>all</option> to select whether
 318                                 to kill only the main process of the
 319                                 unit, the control process or all
 320                                 processes of the unit. If omitted
 321                                 defaults to
 322                                 <option>all</option>.</para></listitem>
 323                         </varlistentry>
 324
 325                         <varlistentry>
 326                                 <term><option>--signal=</option></term>
 327                                 <term><option>-s</option></term>
 328
 329                                 <listitem><para>When used with
 330                                 <command>kill</command>, choose which
 331                                 signal to send to selected
 332                                 processes. Must be one of the well
 333                                 known signal specifiers such as
 334                                 SIGTERM, SIGINT or SIGSTOP. If
 335                                 omitted defaults to
 336                                 <option>SIGTERM</option>.</para></listitem>
 337                         </varlistentry>
 338
 339                         <varlistentry>
 340                                 <term><option>--force</option></term>
 341                                 <term><option>-f</option></term>
 342
 343                                 <listitem><para>When used with
 344                                 <command>enable</command>, override any
 345                                 existing conflicting
 346                                 symlinks.</para></listitem>
 347
 348                                 <listitem><para>When used with
 349                                 <command>halt</command>,
 350                                 <command>poweroff</command>,
 351                                 <command>reboot</command> or
 352                                 <command>kexec</command> execute the
 353                                 selected operation without shutting
 354                                 down all units. However, all processes
 355                                 will be killed forcibly and all file
 356                                 systems are unmounted or remounted
 357                                 read-only. This is hence a drastic but
 358                                 relatively safe option to request an
 359                                 immediate reboot. If
 360                                 <option>--force</option> is specified
 361                                 twice for these operations, they will
 362                                 be executed immediately without
 363                                 terminating any processes or umounting
 364                                 any file systems. Warning: specifying
 365                                 <option>--force</option> twice with
 366                                 any of these operations might result
 367                                 in data loss.</para></listitem>
 368                         </varlistentry>
 369
 370                         <varlistentry>
 371                                 <term><option>--root=</option></term>
 372
 373                                 <listitem><para>When used with
 374                                 <command>enable</command>/<command>disable</command>/<command>is-enabled</command> (and
 375                                 related commands), use alternative
 376                                 root path when looking for unit
 377                                 files.</para></listitem>
 378                         </varlistentry>
 379
 380                         <varlistentry>
 381                                 <term><option>--runtime</option></term>
 382
 383                                 <listitem><para>When used with
 384                                 <command>enable</command>/<command>disable</command>/<command>is-enabled</command> (and related commands), make
 385                                 changes only temporarily, so that they
 386                                 are dropped on the next reboot. This
 387                                 will have the effect that changes are
 388                                 not made in subdirectories of
 389                                 <filename>/etc</filename> but in
 390                                 <filename>/run</filename>, with
 391                                 identical immediate effects, however,
 392                                 since the latter is lost on reboot,
 393                                 the changes are lost
 394                                 too.</para></listitem>
 395                         </varlistentry>
 396
 397                         <varlistentry>
 398                                 <term><option>-H</option></term>
 399                                 <term><option>--host</option></term>
 400
 401                                 <listitem><para>Execute operation
 402                                 remotely. Specify a hostname, or
 403                                 username and hostname separated by @,
 404                                 to connect to. This will use SSH to
 405                                 talk to the remote systemd
 406                                 instance.</para></listitem>
 407                         </varlistentry>
 408
 409                         <varlistentry>
 410                                 <term><option>-P</option></term>
 411                                 <term><option>--privileged</option></term>
 412
 413                                 <listitem><para>Acquire privileges via
 414                                 PolicyKit before executing the
 415                                 operation.</para></listitem>
 416                         </varlistentry>
 417
 418                         <varlistentry>
 419                                 <term><option>--lines=</option></term>
 420                                 <term><option>-n</option></term>
 421
 422                                 <listitem><para>When used with
 423                                 <command>status</command> controls the
 424                                 number of journal lines to show,
 425                                 counting from the most recent
 426                                 ones. Takes a positive integer
 427                                 argument. Defaults to
 428                                 10.</para></listitem>
 429                         </varlistentry>
 430
 431                         <varlistentry>
 432                                 <term><option>--follow</option></term>
 433
 434                                 <listitem><para>When used with
 435                                 <command>status</command> continously
 436                                 prints new journal entries as they are
 437                                 appended to the
 438                                 journal.</para></listitem>
 439                         </varlistentry>
 440
 441                         <varlistentry>
 442                                 <term><option>--output=</option></term>
 443                                 <term><option>-o</option></term>
 444
 445                                 <listitem><para>When used with
 446                                 <command>status</command> controls the
 447                                 formatting of the journal entries that
 448                                 are shown. For the available choices
 449                                 see
 450                                 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. Defaults
 451                                 to
 452                                 <literal>short</literal>.</para></listitem>
 453                         </varlistentry>
 454
 455                 </variablelist>
 456
 457                 <para>The following commands are understood:</para>
 458
 459                 <variablelist>
 460                         <varlistentry>
 461                                 <term><command>list-units</command></term>
 462
 463                                 <listitem><para>List known units.</para></listitem>
 464                         </varlistentry>
 465                         <varlistentry>
 466                                 <term><command>start [NAME...]</command></term>
 467
 468                                 <listitem><para>Start (activate) one
 469                                 or more units specified on the command
 470                                 line.</para></listitem>
 471                         </varlistentry>
 472                         <varlistentry>
 473                                 <term><command>stop [NAME...]</command></term>
 474
 475                                 <listitem><para>Stop (deactivate) one
 476                                 or more units specified on the command
 477                                 line.</para></listitem>
 478                         </varlistentry>
 479                         <varlistentry>
 480                                 <term><command>reload [NAME...]</command></term>
 481
 482                                 <listitem><para>Asks all units listed
 483                                 on the command line to reload their
 484                                 configuration. Note that this will
 485                                 reload the service-specific
 486                                 configuration, not the unit
 487                                 configuration file of systemd. If you
 488                                 want systemd to reload the
 489                                 configuration file of a unit use the
 490                                 <command>daemon-reload</command>
 491                                 command. In other words: for the
 492                                 example case of Apache, this will
 493                                 reload Apache's
 494                                 <filename>httpd.conf</filename> in the
 495                                 web server, not the
 496                                 <filename>apache.service</filename>
 497                                 systemd unit file. </para>
 498
 499                                 <para>This command should not be
 500                                 confused with the
 501                                 <command>daemon-reload</command> or
 502                                 <command>load</command>
 503                                 commands.</para></listitem>
 504
 505                         </varlistentry>
 506                         <varlistentry>
 507                                 <term><command>restart [NAME...]</command></term>
 508
 509                                 <listitem><para>Restart one or more
 510                                 units specified on the command
 511                                 line. If the units are not running yet
 512                                 they will be
 513                                 started.</para></listitem>
 514                         </varlistentry>
 515                         <varlistentry>
 516                                 <term><command>try-restart [NAME...]</command></term>
 517
 518                                 <listitem><para>Restart one or more
 519                                 units specified on the command
 520                                 line if the units are running. Do
 521                                 nothing if units are not running.
 522                                 Note that for compatibility
 523                                 with Red Hat init scripts
 524                                 <command>condrestart</command> is
 525                                 equivalent to this command.</para></listitem>
 526                         </varlistentry>
 527                         <varlistentry>
 528                                 <term><command>reload-or-restart [NAME...]</command></term>
 529
 530                                 <listitem><para>Reload one or more
 531                                 units if they support it. If not,
 532                                 restart them instead. If the units
 533                                 are not running yet they will be
 534                                 started.</para></listitem>
 535                         </varlistentry>
 536                         <varlistentry>
 537                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 538
 539                                 <listitem><para>Reload one or more
 540                                 units if they support it. If not,
 541                                 restart them instead. Do nothing if
 542                                 the units are not running. Note that
 543                                 for compatibility with SysV init
 544                                 scripts
 545                                 <command>force-reload</command> is
 546                                 equivalent to this
 547                                 command.</para></listitem>
 548                         </varlistentry>
 549                         <varlistentry>
 550                                 <term><command>isolate [NAME]</command></term>
 551
 552                                 <listitem><para>Start the unit
 553                                 specified on the command line and its
 554                                 dependencies and stop all others.</para>
 555
 556                                 <para>This is similar to changing the
 557                                 runlevel in a traditional init system. The
 558                                 <command>isolate</command> command will
 559                                 immediately stop processes that are not
 560                                 enabled in the new unit, possibly including
 561                                 the graphical environment or terminal you
 562                                 are currently using.</para>
 563
 564                                 <para>Note that this works only on units
 565                                 where <option>AllowIsolate=</option> is
 566                                 enabled. See
 567                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 568                                 for details.</para></listitem>
 569                         </varlistentry>
 570                         <varlistentry>
 571                                 <term><command>kill [NAME...]</command></term>
 572
 573                                 <listitem><para>Send a signal to one
 574                                 or more processes of the unit. Use
 575                                 <option>--kill-who=</option> to select
 576                                 which process to kill. Use
 577                                 <option>--kill-mode=</option> to
 578                                 select the kill mode and
 579                                 <option>--signal=</option> to select
 580                                 the signal to send.</para></listitem>
 581                         </varlistentry>
 582                         <varlistentry>
 583                                 <term><command>is-active [NAME...]</command></term>
 584
 585                                 <listitem><para>Check whether any of
 586                                 the specified units are active
 587                                 (i.e. running). Returns an exit code
 588                                 0 if at least one is active, non-zero
 589                                 otherwise. Unless
 590                                 <option>--quiet</option> is specified
 591                                 this will also print the current unit
 592                                 state to STDOUT.</para></listitem>
 593                         </varlistentry>
 594                         <varlistentry>
 595                                 <term><command>status [NAME...|PID...]</command></term>
 596
 597                                 <listitem><para>Show terse runtime
 598                                 status information about one or more
 599                                 units, followed by its most recent log
 600                                 data from the journal. This function
 601                                 is intended to generate human-readable
 602                                 output. If you are looking for
 603                                 computer-parsable output, use
 604                                 <command>show</command> instead. If a
 605                                 PID is passed information about the
 606                                 unit the process of the PID belongs to
 607                                 is shown.</para></listitem>
 608                         </varlistentry>
 609                         <varlistentry>
 610                                 <term><command>show [NAME...|JOB...]</command></term>
 611
 612                                 <listitem><para>Show properties of one
 613                                 or more units, jobs or the manager
 614                                 itself. If no argument is specified
 615                                 properties of the manager will be
 616                                 shown. If a unit name is specified
 617                                 properties of the unit is shown, and
 618                                 if a job id is specified properties of
 619                                 the job is shown. By default, empty
 620                                 properties are suppressed. Use
 621                                 <option>--all</option> to show those
 622                                 too. To select specific properties to
 623                                 show use
 624                                 <option>--property=</option>. This
 625                                 command is intended to be used
 626                                 whenever computer-parsable output is
 627                                 required. Use
 628                                 <command>status</command> if you are
 629                                 looking for formatted human-readable
 630                                 output.</para></listitem>
 631                         </varlistentry>
 632
 633                         <varlistentry>
 634                                 <term><command>reset-failed [NAME...]</command></term>
 635
 636                                 <listitem><para>Reset the
 637                                 '<literal>failed</literal>' state of the
 638                                 specified units, or if no unit name is
 639                                 passed of all units. When a unit fails
 640                                 in some way (i.e. process exiting with
 641                                 non-zero error code, terminating
 642                                 abnormally or timing out) it will
 643                                 automatically enter the
 644                                 '<literal>failed</literal>' state and
 645                                 its exit code and status is recorded
 646                                 for introspection by the administrator
 647                                 until the service is restarted or
 648                                 reset with this
 649                                 command.</para></listitem>
 650                         </varlistentry>
 651
 652                         <varlistentry>
 653                                 <term><command>list-unit-files</command></term>
 654
 655                                 <listitem><para>List installed unit files.
 656                                 </para></listitem>
 657                         </varlistentry>
 658
 659                         <varlistentry>
 660                                 <term><command>enable [NAME...]</command></term>
 661
 662                                 <listitem><para>Enable one or more
 663                                 unit files, as specified on the
 664                                 command line. This will create a
 665                                 number of symlinks as encoded in the
 666                                 <literal>[Install]</literal> sections
 667                                 of the unit files. After the symlinks
 668                                 have been created the systemd
 669                                 configuration is reloaded (in a way
 670                                 that is equivalent to
 671                                 <command>daemon-reload</command>) to
 672                                 ensure the changes are taken into
 673                                 account immediately. Note that this
 674                                 does not have the effect that any of
 675                                 the units enabled are also started at
 676                                 the same time. If this is desired a
 677                                 separate <command>start</command>
 678                                 command must be invoked for the
 679                                 unit.</para>
 680
 681                                 <para>This command will
 682                                 print the actions executed. This
 683                                 output may be suppressed by passing
 684                                 <option>--quiet</option>.</para>
 685
 686                                 <para>Note that this operation creates
 687                                 only the suggested symlinks for the
 688                                 units. While this command is the
 689                                 recommended way to manipulate the unit
 690                                 configuration directory, the
 691                                 administrator is free to make
 692                                 additional changes manually, by
 693                                 placing or removing symlinks in the
 694                                 directory. This is particularly useful
 695                                 to create configurations that deviate
 696                                 from the suggested default
 697                                 installation. In this case the
 698                                 administrator must make sure to invoke
 699                                 <command>daemon-reload</command>
 700                                 manually as necessary, to ensure his
 701                                 changes are taken into account.</para>
 702
 703                                 <para>Enabling units should not be
 704                                 confused with starting (activating)
 705                                 units, as done by the
 706                                 <command>start</command>
 707                                 command. Enabling and starting units
 708                                 is orthogonal: units may be enabled
 709                                 without being started and started
 710                                 without being enabled. Enabling simply
 711                                 hooks the unit into various suggested
 712                                 places (for example, so that the unit
 713                                 is automatically started on boot or
 714                                 when a particular kind of hardware is
 715                                 plugged in). Starting actually spawns
 716                                 the daemon process (in case of service
 717                                 units), or binds the socket (in case
 718                                 of socket units), and so
 719                                 on.</para>
 720
 721                                 <para>Depending on whether
 722                                 <option>--system</option>,
 723                                 <option>--user</option> or
 724                                 <option>--global</option> is specified
 725                                 this enables the unit for the system,
 726                                 for the calling user only
 727                                 or for all future logins of all
 728                                 users. Note that in the latter case no
 729                                 systemd daemon configuration is
 730                                 reloaded.</para>
 731                                 </listitem>
 732                         </varlistentry>
 733
 734                         <varlistentry>
 735                                 <term><command>disable [NAME...]</command></term>
 736
 737                                 <listitem><para>Disables one or more
 738                                 units. This removes all symlinks to
 739                                 the specified unit files from the unit
 740                                 configuration directory, and hence
 741                                 undoes the changes made by
 742                                 <command>enable</command>. Note
 743                                 however that this removes
 744                                 all symlinks to the unit files
 745                                 (i.e. including manual additions), not
 746                                 just those actually created by
 747                                 <command>enable</command>. This call
 748                                 implicitly reloads the systemd daemon
 749                                 configuration after completing the
 750                                 disabling of the units. Note that this
 751                                 command does not implicitly stop the
 752                                 units that is being disabled. If this
 753                                 is desired an additional
 754                                 <command>stop</command>command should
 755                                 be executed afterwards.</para>
 756
 757                                 <para>This command will print the
 758                                 actions executed. This output may be
 759                                 suppressed by passing
 760                                 <option>--quiet</option>.</para>
 761                                 </listitem>
 762
 763                                 <para>This command honors
 764                                 <option>--system</option>,
 765                                 <option>--user</option>,
 766                                 <option>--global</option> in a similar
 767                                 way as
 768                                 <command>enable</command>.</para>
 769                         </varlistentry>
 770
 771                         <varlistentry>
 772                                 <term><command>is-enabled [NAME...]</command></term>
 773
 774                                 <listitem><para>Checks whether any of
 775                                 the specified unit files is enabled
 776                                 (as with
 777                                 <command>enable</command>). Returns an
 778                                 exit code of 0 if at least one is
 779                                 enabled, non-zero otherwise. Prints
 780                                 the current enable status. To suppress
 781                                 this output use
 782                                 <option>--quiet</option>.</para></listitem>
 783                         </varlistentry>
 784
 785                         <varlistentry>
 786                                 <term><command>reenable [NAME...]</command></term>
 787
 788                                 <listitem><para>Reenable one or more
 789                                 unit files, as specified on the
 790                                 command line. This is a combination of
 791                                 <command>disable</command> and
 792                                 <command>enable</command> and is
 793                                 useful to reset the symlinks a unit is
 794                                 enabled with to the defaults
 795                                 configured in the
 796                                 <literal>[Install]</literal> section
 797                                 of the unit file.</para>
 798                                 </listitem>
 799                         </varlistentry>
 800
 801                         <varlistentry>
 802                                 <term><command>preset [NAME...]</command></term>
 803
 804                                 <listitem><para>Reset one or more unit
 805                                 files, as specified on the command
 806                                 line, to the defaults configured in a
 807                                 preset file. This has the same effect
 808                                 as <command>disable</command> or
 809                                 <command>enable</command>, depending
 810                                 how the unit is listed in the preset
 811                                 files.</para>
 812                                 </listitem>
 813                         </varlistentry>
 814
 815                         <varlistentry>
 816                                 <term><command>mask [NAME...]</command></term>
 817
 818                                 <listitem><para>Mask one or more unit
 819                                 files, as specified on the command
 820                                 line. This will link these units to
 821                                 <filename>/dev/null</filename>, making
 822                                 it impossible to start them. This is a stronger version
 823                                 of <command>disable</command>, since
 824                                 it prohibits all kinds of activation
 825                                 of the unit, including manual
 826                                 activation. Use this option with
 827                                 care.</para>
 828                                 </listitem>
 829                         </varlistentry>
 830
 831                         <varlistentry>
 832                                 <term><command>unmask [NAME...]</command></term>
 833
 834                                 <listitem><para>Unmask one or more
 835                                 unit files, as specified on the
 836                                 command line. This will undo the
 837                                 effect of
 838                                 <command>mask</command>.</para>
 839                                 </listitem>
 840                         </varlistentry>
 841
 842                         <varlistentry>
 843                                 <term><command>link [NAME...]</command></term>
 844
 845                                 <listitem><para>Link a unit file that
 846                                 is not in the unit file search paths
 847                                 into the unit file search path. This
 848                                 requires an absolute path to a unit
 849                                 file. The effect of this can be undone
 850                                 with <command>disable</command>. The
 851                                 effect of this command is that a unit
 852                                 file is available for
 853                                 <command>start</command> and other
 854                                 commands although it isn't installed
 855                                 directly in the unit search
 856                                 path.</para>
 857                                 </listitem>
 858                         </varlistentry>
 859
 860                         <varlistentry>
 861                                 <term><command>load [NAME...]</command></term>
 862
 863                                 <listitem><para>Load one or more units
 864                                 specified on the command line. This
 865                                 will simply load their configuration
 866                                 from disk, but not start them. To
 867                                 start them you need to use the
 868                                 <command>start</command> command which
 869                                 will implicitly load a unit that has
 870                                 not been loaded yet. Note that systemd
 871                                 garbage collects loaded units that are
 872                                 not active or referenced by an active
 873                                 unit. This means that units loaded
 874                                 this way will usually not stay loaded
 875                                 for long. Also note that this command
 876                                 cannot be used to reload unit
 877                                 configuration. Use the
 878                                 <command>daemon-reload</command>
 879                                 command for that. All in all, this
 880                                 command is of little use except for
 881                                 debugging.</para>
 882                                 <para>This command should not be
 883                                 confused with the
 884                                 <command>daemon-reload</command> or
 885                                 <command>reload</command>
 886                                 commands.</para></listitem>
 887                         </varlistentry>
 888                         <varlistentry>
 889                                 <term><command>list-jobs</command></term>
 890
 891                                 <listitem><para>List jobs that are in progress.</para></listitem>
 892                         </varlistentry>
 893                         <varlistentry>
 894                                 <term><command>cancel [JOB...]</command></term>
 895
 896                                 <listitem><para>Cancel one or more
 897                                 jobs specified on the command line by
 898                                 their numeric job
 899                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 900                         </varlistentry>
 901                         <varlistentry>
 902                                 <term><command>dump</command></term>
 903
 904                                 <listitem><para>Dump server
 905                                 status. This will output a (usually
 906                                 very long) human readable manager
 907                                 status dump. Its format is subject to
 908                                 change without notice and should not
 909                                 be parsed by
 910                                 applications.</para></listitem>
 911                         </varlistentry>
 912                         <varlistentry>
 913                                 <term><command>dot</command></term>
 914
 915                                 <listitem><para>Generate textual
 916                                 dependency graph description in dot
 917                                 format for further processing with the
 918                                 GraphViz
 919                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 920                                 tool. Use a command line like
 921                                 <command>systemctl dot | dot -Tsvg >
 922                                 systemd.svg</command> to generate a
 923                                 graphical dependency tree. Unless
 924                                 <option>--order</option> or
 925                                 <option>--require</option> is passed
 926                                 the generated graph will show both
 927                                 ordering and requirement
 928                                 dependencies.</para></listitem>
 929                         </varlistentry>
 930                         <varlistentry>
 931                                 <term><command>snapshot [NAME]</command></term>
 932
 933                                 <listitem><para>Create a snapshot. If
 934                                 a snapshot name is specified, the new
 935                                 snapshot will be named after it. If
 936                                 none is specified an automatic
 937                                 snapshot name is generated. In either
 938                                 case, the snapshot name used is
 939                                 printed to STDOUT, unless
 940                                 <option>--quiet</option> is
 941                                 specified.</para>
 942
 943                                 <para>A snapshot refers to a saved
 944                                 state of the systemd manager. It is
 945                                 implemented itself as a unit that is
 946                                 generated dynamically with this
 947                                 command and has dependencies on all
 948                                 units active at the time. At a later
 949                                 time the user may return to this state
 950                                 by using the
 951                                 <command>isolate</command> command on
 952                                 the snapshot unit.</para></listitem>
 953
 954                                 <para>Snapshots are only useful for
 955                                 saving and restoring which units are
 956                                 running or are stopped, they do not
 957                                 save/restore any other
 958                                 state. Snapshots are dynamic and lost
 959                                 on reboot.</para>
 960                         </varlistentry>
 961                         <varlistentry>
 962                                 <term><command>delete [NAME...]</command></term>
 963
 964                                 <listitem><para>Remove a snapshot
 965                                 previously created with
 966                                 <command>snapshot</command>.</para></listitem>
 967                         </varlistentry>
 968                         <varlistentry>
 969                                 <term><command>daemon-reload</command></term>
 970
 971                                 <listitem><para>Reload systemd manager
 972                                 configuration. This will reload all
 973                                 unit files and recreate the entire
 974                                 dependency tree. While the daemon is
 975                                 reloaded, all sockets systemd listens
 976                                 on on behalf of user configuration will
 977                                 stay accessible.</para> <para>This
 978                                 command should not be confused with
 979                                 the <command>load</command> or
 980                                 <command>reload</command>
 981                                 commands.</para></listitem>
 982                         </varlistentry>
 983                         <varlistentry>
 984                                 <term><command>daemon-reexec</command></term>
 985
 986                                 <listitem><para>Reexecute the systemd
 987                                 manager. This will serialize the
 988                                 manager state, reexecute the process
 989                                 and deserialize the state again. This
 990                                 command is of little use except for
 991                                 debugging and package
 992                                 upgrades. Sometimes it might be
 993                                 helpful as a heavy-weight
 994                                 <command>daemon-reload</command>. While
 995                                 the daemon is reexecuted all sockets
 996                                 systemd listens on on behalf of user
 997                                 configuration will stay
 998                                 accessible.</para></listitem>
 999                         </varlistentry>
1000                         <varlistentry>
1001                                 <term><command>show-environment</command></term>
1002
1003                                 <listitem><para>Dump the systemd
1004                                 manager environment block. The
1005                                 environment block will be dumped in
1006                                 straight-forward form suitable for
1007                                 sourcing into a shell script. This
1008                                 environment block will be passed to
1009                                 all processes the manager
1010                                 spawns.</para></listitem>
1011                         </varlistentry>
1012                         <varlistentry>
1013                                 <term><command>set-environment [NAME=VALUE...]</command></term>
1014
1015                                 <listitem><para>Set one or more
1016                                 systemd manager environment variables,
1017                                 as specified on the command
1018                                 line.</para></listitem>
1019                         </varlistentry>
1020                         <varlistentry>
1021                                 <term><command>unset-environment [NAME...]</command></term>
1022
1023                                 <listitem><para>Unset one or more
1024                                 systemd manager environment
1025                                 variables. If only a variable name is
1026                                 specified it will be removed
1027                                 regardless of its value. If a variable
1028                                 and a value are specified the variable
1029                                 is only removed if it has the
1030                                 specified value.</para></listitem>
1031                         </varlistentry>
1032                         <varlistentry>
1033                                 <term><command>default</command></term>
1034
1035                                 <listitem><para>Enter default
1036                                 mode. This is mostly equivalent to
1037                                 <command>start
1038                                 default.target</command>.</para></listitem>
1039                         </varlistentry>
1040                         <varlistentry>
1041                                 <term><command>rescue</command></term>
1042
1043                                 <listitem><para>Enter rescue
1044                                 mode. This is mostly equivalent to
1045                                 <command>isolate
1046                                 rescue.target</command> but also
1047                                 prints a wall message to all
1048                                 users.</para></listitem>
1049                         </varlistentry>
1050                         <varlistentry>
1051                                 <term><command>emergency</command></term>
1052
1053                                 <listitem><para>Enter emergency
1054                                 mode. This is mostly equivalent to
1055                                 <command>isolate
1056                                 emergency.target</command> but also
1057                                 prints a wall message to all
1058                                 users.</para></listitem>
1059                         </varlistentry>
1060                         <varlistentry>
1061                                 <term><command>halt</command></term>
1062
1063                                 <listitem><para>Shut down and halt the
1064                                 system. This is mostly equivalent to
1065                                 <command>start halt.target</command>
1066                                 but also prints a wall message to all
1067                                 users.  If combined with
1068                                 <option>--force</option> shutdown of
1069                                 all running services is skipped,
1070                                 however all processes are killed and
1071                                 all file systems are unmounted or
1072                                 mounted read-only, immediately
1073                                 followed by the system halt.  If
1074                                 <option>--force</option> is specified
1075                                 twice the the operation is immediately
1076                                 executed without terminating any
1077                                 processes or unmounting any file
1078                                 systems. This may result in data
1079                                 loss.</para></listitem>
1080                         </varlistentry>
1081                         <varlistentry>
1082                                 <term><command>poweroff</command></term>
1083
1084                                 <listitem><para>Shut down and
1085                                 power-off the system. This is mostly
1086                                 equivalent to <command>start
1087                                 poweroff.target</command> but also
1088                                 prints a wall message to all users. If
1089                                 combined with <option>--force</option>
1090                                 shutdown of all running services is
1091                                 skipped, however all processes are
1092                                 killed and all file systems are
1093                                 unmounted or mounted read-only,
1094                                 immediately followed by the powering
1095                                 off. If <option>--force</option> is
1096                                 specified twice the the operation is
1097                                 immediately executed without
1098                                 terminating any processes or
1099                                 unmounting any file systems. This may
1100                                 result in data loss.</para></listitem>
1101                         </varlistentry>
1102                         <varlistentry>
1103                                 <term><command>reboot</command></term>
1104
1105                                 <listitem><para>Shut down and reboot
1106                                 the system. This is mostly equivalent
1107                                 to <command>start
1108                                 reboot.target</command> but also
1109                                 prints a wall message to all users. If
1110                                 combined with <option>--force</option>
1111                                 shutdown of all running services is
1112                                 skipped, however all processes are
1113                                 killed and all file systems are
1114                                 unmounted or mounted read-only,
1115                                 immediately followed by the reboot. If
1116                                 <option>--force</option> is specified
1117                                 twice the the operation is immediately
1118                                 executed without terminating any
1119                                 processes or unmounting any file
1120                                 systems. This may result in data
1121                                 loss.</para></listitem>
1122                         </varlistentry>
1123                         <varlistentry>
1124                                 <term><command>kexec</command></term>
1125
1126                                 <listitem><para>Shut down and reboot
1127                                 the system via kexec. This is mostly
1128                                 equivalent to <command>start
1129                                 kexec.target</command> but also prints
1130                                 a wall message to all users. If
1131                                 combined with <option>--force</option>
1132                                 shutdown of all running services is
1133                                 skipped, however all processes are killed
1134                                 and all file systems are unmounted or
1135                                 mounted read-only, immediately
1136                                 followed by the
1137                                 reboot.</para></listitem>
1138                         </varlistentry>
1139                         <varlistentry>
1140                                 <term><command>exit</command></term>
1141
1142                                 <listitem><para>Ask the systemd
1143                                 manager to quit. This is only
1144                                 supported for user service managers
1145                                 (i.e. in conjunction with the
1146                                 <option>--user</option> option) and
1147                                 will fail otherwise.</para></listitem>
1148                         </varlistentry>
1149                 </variablelist>
1150
1151         </refsect1>
1152
1153         <refsect1>
1154                 <title>Exit status</title>
1155
1156                 <para>On success 0 is returned, a non-zero failure
1157                 code otherwise.</para>
1158         </refsect1>
1159
1160         <refsect1>
1161                 <title>Environment</title>
1162
1163                 <variablelist>
1164                         <varlistentry>
1165                                 <term><varname>$SYSTEMD_PAGER</varname></term>
1166                                 <listitem><para>Pager to use when
1167                                 <option>--no-pager</option> is not given;
1168                                 overrides <varname>$PAGER</varname>.  Setting
1169                                 this to an empty string or the value
1170                                 <literal>cat</literal> is equivalent to passing
1171                                 <option>--no-pager</option>.</para></listitem>
1172                         </varlistentry>
1173                 </variablelist>
1174         </refsect1>
1175
1176         <refsect1>
1177                 <title>See Also</title>
1178                 <para>
1179                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1180                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1181                         <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1182                         <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1183                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1184                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1185                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
1186                 </para>
1187         </refsect1>
1188
1189 </refentry>