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.
  19
  20   You should have received a copy of the GNU General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
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  23
  24 <refentry id="systemctl">
  25
  26         <refentryinfo>
  27                 <title>systemctl</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>systemctl</refentrytitle>
  42                 <manvolnum>1</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemctl</refname>
  47                 <refpurpose>Control the systemd system and 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                                 <term><option>-f</option></term>
 434
 435                                 <listitem><para>When used with
 436                                 <command>status</command> continously
 437                                 prints new journal entries as they are
 438                                 appended to the
 439                                 journal.</para></listitem>
 440                         </varlistentry>
 441
 442                         <varlistentry>
 443                                 <term><option>--output=</option></term>
 444                                 <term><option>-o</option></term>
 445
 446                                 <listitem><para>When used with
 447                                 <command>status</command> controls the
 448                                 formatting of the journal entries that
 449                                 are shown. For the available choices
 450                                 see
 451                                 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. Defaults
 452                                 to
 453                                 <literal>short</literal>.</para></listitem>
 454                         </varlistentry>
 455
 456                 </variablelist>
 457
 458                 <para>The following commands are understood:</para>
 459
 460                 <variablelist>
 461                         <varlistentry>
 462                                 <term><command>list-units</command></term>
 463
 464                                 <listitem><para>List known units.</para></listitem>
 465                         </varlistentry>
 466                         <varlistentry>
 467                                 <term><command>start [NAME...]</command></term>
 468
 469                                 <listitem><para>Start (activate) one
 470                                 or more units specified on the command
 471                                 line.</para></listitem>
 472                         </varlistentry>
 473                         <varlistentry>
 474                                 <term><command>stop [NAME...]</command></term>
 475
 476                                 <listitem><para>Stop (deactivate) one
 477                                 or more units specified on the command
 478                                 line.</para></listitem>
 479                         </varlistentry>
 480                         <varlistentry>
 481                                 <term><command>reload [NAME...]</command></term>
 482
 483                                 <listitem><para>Asks all units listed
 484                                 on the command line to reload their
 485                                 configuration. Note that this will
 486                                 reload the service-specific
 487                                 configuration, not the unit
 488                                 configuration file of systemd. If you
 489                                 want systemd to reload the
 490                                 configuration file of a unit use the
 491                                 <command>daemon-reload</command>
 492                                 command. In other words: for the
 493                                 example case of Apache, this will
 494                                 reload Apache's
 495                                 <filename>httpd.conf</filename> in the
 496                                 web server, not the
 497                                 <filename>apache.service</filename>
 498                                 systemd unit file. </para>
 499
 500                                 <para>This command should not be
 501                                 confused with the
 502                                 <command>daemon-reload</command> or
 503                                 <command>load</command>
 504                                 commands.</para></listitem>
 505
 506                         </varlistentry>
 507                         <varlistentry>
 508                                 <term><command>restart [NAME...]</command></term>
 509
 510                                 <listitem><para>Restart one or more
 511                                 units specified on the command
 512                                 line. If the units are not running yet
 513                                 they will be
 514                                 started.</para></listitem>
 515                         </varlistentry>
 516                         <varlistentry>
 517                                 <term><command>try-restart [NAME...]</command></term>
 518
 519                                 <listitem><para>Restart one or more
 520                                 units specified on the command
 521                                 line if the units are running. Do
 522                                 nothing if units are not running.
 523                                 Note that for compatibility
 524                                 with Red Hat init scripts
 525                                 <command>condrestart</command> is
 526                                 equivalent to this command.</para></listitem>
 527                         </varlistentry>
 528                         <varlistentry>
 529                                 <term><command>reload-or-restart [NAME...]</command></term>
 530
 531                                 <listitem><para>Reload one or more
 532                                 units if they support it. If not,
 533                                 restart them instead. If the units
 534                                 are not running yet they will be
 535                                 started.</para></listitem>
 536                         </varlistentry>
 537                         <varlistentry>
 538                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 539
 540                                 <listitem><para>Reload one or more
 541                                 units if they support it. If not,
 542                                 restart them instead. Do nothing if
 543                                 the units are not running. Note that
 544                                 for compatibility with SysV init
 545                                 scripts
 546                                 <command>force-reload</command> is
 547                                 equivalent to this
 548                                 command.</para></listitem>
 549                         </varlistentry>
 550                         <varlistentry>
 551                                 <term><command>isolate [NAME]</command></term>
 552
 553                                 <listitem><para>Start the unit
 554                                 specified on the command line and its
 555                                 dependencies and stop all others.</para>
 556
 557                                 <para>This is similar to changing the
 558                                 runlevel in a traditional init system. The
 559                                 <command>isolate</command> command will
 560                                 immediately stop processes that are not
 561                                 enabled in the new unit, possibly including
 562                                 the graphical environment or terminal you
 563                                 are currently using.</para>
 564
 565                                 <para>Note that this works only on units
 566                                 where <option>AllowIsolate=</option> is
 567                                 enabled. See
 568                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 569                                 for details.</para></listitem>
 570                         </varlistentry>
 571                         <varlistentry>
 572                                 <term><command>kill [NAME...]</command></term>
 573
 574                                 <listitem><para>Send a signal to one
 575                                 or more processes of the unit. Use
 576                                 <option>--kill-who=</option> to select
 577                                 which process to kill. Use
 578                                 <option>--kill-mode=</option> to
 579                                 select the kill mode and
 580                                 <option>--signal=</option> to select
 581                                 the signal to send.</para></listitem>
 582                         </varlistentry>
 583                         <varlistentry>
 584                                 <term><command>is-active [NAME...]</command></term>
 585
 586                                 <listitem><para>Check whether any of
 587                                 the specified units are active
 588                                 (i.e. running). Returns an exit code
 589                                 0 if at least one is active, non-zero
 590                                 otherwise. Unless
 591                                 <option>--quiet</option> is specified
 592                                 this will also print the current unit
 593                                 state to STDOUT.</para></listitem>
 594                         </varlistentry>
 595                         <varlistentry>
 596                                 <term><command>status [NAME...|PID...]</command></term>
 597
 598                                 <listitem><para>Show terse runtime
 599                                 status information about one or more
 600                                 units, followed by its most recent log
 601                                 data from the journal. This function
 602                                 is intended to generate human-readable
 603                                 output. If you are looking for
 604                                 computer-parsable output, use
 605                                 <command>show</command> instead. If a
 606                                 PID is passed information about the
 607                                 unit the process of the PID belongs to
 608                                 is shown.</para></listitem>
 609                         </varlistentry>
 610                         <varlistentry>
 611                                 <term><command>show [NAME...|JOB...]</command></term>
 612
 613                                 <listitem><para>Show properties of one
 614                                 or more units, jobs or the manager
 615                                 itself. If no argument is specified
 616                                 properties of the manager will be
 617                                 shown. If a unit name is specified
 618                                 properties of the unit is shown, and
 619                                 if a job id is specified properties of
 620                                 the job is shown. By default, empty
 621                                 properties are suppressed. Use
 622                                 <option>--all</option> to show those
 623                                 too. To select specific properties to
 624                                 show use
 625                                 <option>--property=</option>. This
 626                                 command is intended to be used
 627                                 whenever computer-parsable output is
 628                                 required. Use
 629                                 <command>status</command> if you are
 630                                 looking for formatted human-readable
 631                                 output.</para></listitem>
 632                         </varlistentry>
 633
 634                         <varlistentry>
 635                                 <term><command>reset-failed [NAME...]</command></term>
 636
 637                                 <listitem><para>Reset the
 638                                 '<literal>failed</literal>' state of the
 639                                 specified units, or if no unit name is
 640                                 passed of all units. When a unit fails
 641                                 in some way (i.e. process exiting with
 642                                 non-zero error code, terminating
 643                                 abnormally or timing out) it will
 644                                 automatically enter the
 645                                 '<literal>failed</literal>' state and
 646                                 its exit code and status is recorded
 647                                 for introspection by the administrator
 648                                 until the service is restarted or
 649                                 reset with this
 650                                 command.</para></listitem>
 651                         </varlistentry>
 652
 653                         <varlistentry>
 654                                 <term><command>list-unit-files</command></term>
 655
 656                                 <listitem><para>List installed unit files.
 657                                 </para></listitem>
 658                         </varlistentry>
 659
 660                         <varlistentry>
 661                                 <term><command>enable [NAME...]</command></term>
 662
 663                                 <listitem><para>Enable one or more
 664                                 unit files, as specified on the
 665                                 command line. This will create a
 666                                 number of symlinks as encoded in the
 667                                 <literal>[Install]</literal> sections
 668                                 of the unit files. After the symlinks
 669                                 have been created the systemd
 670                                 configuration is reloaded (in a way
 671                                 that is equivalent to
 672                                 <command>daemon-reload</command>) to
 673                                 ensure the changes are taken into
 674                                 account immediately. Note that this
 675                                 does not have the effect that any of
 676                                 the units enabled are also started at
 677                                 the same time. If this is desired a
 678                                 separate <command>start</command>
 679                                 command must be invoked for the
 680                                 unit.</para>
 681
 682                                 <para>This command will
 683                                 print the actions executed. This
 684                                 output may be suppressed by passing
 685                                 <option>--quiet</option>.</para>
 686
 687                                 <para>Note that this operation creates
 688                                 only the suggested symlinks for the
 689                                 units. While this command is the
 690                                 recommended way to manipulate the unit
 691                                 configuration directory, the
 692                                 administrator is free to make
 693                                 additional changes manually, by
 694                                 placing or removing symlinks in the
 695                                 directory. This is particularly useful
 696                                 to create configurations that deviate
 697                                 from the suggested default
 698                                 installation. In this case the
 699                                 administrator must make sure to invoke
 700                                 <command>daemon-reload</command>
 701                                 manually as necessary, to ensure his
 702                                 changes are taken into account.</para>
 703
 704                                 <para>Enabling units should not be
 705                                 confused with starting (activating)
 706                                 units, as done by the
 707                                 <command>start</command>
 708                                 command. Enabling and starting units
 709                                 is orthogonal: units may be enabled
 710                                 without being started and started
 711                                 without being enabled. Enabling simply
 712                                 hooks the unit into various suggested
 713                                 places (for example, so that the unit
 714                                 is automatically started on boot or
 715                                 when a particular kind of hardware is
 716                                 plugged in). Starting actually spawns
 717                                 the daemon process (in case of service
 718                                 units), or binds the socket (in case
 719                                 of socket units), and so
 720                                 on.</para>
 721
 722                                 <para>Depending on whether
 723                                 <option>--system</option>,
 724                                 <option>--user</option> or
 725                                 <option>--global</option> is specified
 726                                 this enables the unit for the system,
 727                                 for the calling user only
 728                                 or for all future logins of all
 729                                 users. Note that in the latter case no
 730                                 systemd daemon configuration is
 731                                 reloaded.</para>
 732                                 </listitem>
 733                         </varlistentry>
 734
 735                         <varlistentry>
 736                                 <term><command>disable [NAME...]</command></term>
 737
 738                                 <listitem><para>Disables one or more
 739                                 units. This removes all symlinks to
 740                                 the specified unit files from the unit
 741                                 configuration directory, and hence
 742                                 undoes the changes made by
 743                                 <command>enable</command>. Note
 744                                 however that this removes
 745                                 all symlinks to the unit files
 746                                 (i.e. including manual additions), not
 747                                 just those actually created by
 748                                 <command>enable</command>. This call
 749                                 implicitly reloads the systemd daemon
 750                                 configuration after completing the
 751                                 disabling of the units. Note that this
 752                                 command does not implicitly stop the
 753                                 units that is being disabled. If this
 754                                 is desired an additional
 755                                 <command>stop</command>command should
 756                                 be executed afterwards.</para>
 757
 758                                 <para>This command will print the
 759                                 actions executed. This output may be
 760                                 suppressed by passing
 761                                 <option>--quiet</option>.</para>
 762                                 </listitem>
 763
 764                                 <para>This command honors
 765                                 <option>--system</option>,
 766                                 <option>--user</option>,
 767                                 <option>--global</option> in a similar
 768                                 way as
 769                                 <command>enable</command>.</para>
 770                         </varlistentry>
 771
 772                         <varlistentry>
 773                                 <term><command>is-enabled [NAME...]</command></term>
 774
 775                                 <listitem><para>Checks whether any of
 776                                 the specified unit files is enabled
 777                                 (as with
 778                                 <command>enable</command>). Returns an
 779                                 exit code of 0 if at least one is
 780                                 enabled, non-zero otherwise. Prints
 781                                 the current enable status. To suppress
 782                                 this output use
 783                                 <option>--quiet</option>.</para></listitem>
 784                         </varlistentry>
 785
 786                         <varlistentry>
 787                                 <term><command>reenable [NAME...]</command></term>
 788
 789                                 <listitem><para>Reenable one or more
 790                                 unit files, as specified on the
 791                                 command line. This is a combination of
 792                                 <command>disable</command> and
 793                                 <command>enable</command> and is
 794                                 useful to reset the symlinks a unit is
 795                                 enabled with to the defaults
 796                                 configured in the
 797                                 <literal>[Install]</literal> section
 798                                 of the unit file.</para>
 799                                 </listitem>
 800                         </varlistentry>
 801
 802                         <varlistentry>
 803                                 <term><command>preset [NAME...]</command></term>
 804
 805                                 <listitem><para>Reset one or more unit
 806                                 files, as specified on the command
 807                                 line, to the defaults configured in a
 808                                 preset file. This has the same effect
 809                                 as <command>disable</command> or
 810                                 <command>enable</command>, depending
 811                                 how the unit is listed in the preset
 812                                 files.</para>
 813                                 </listitem>
 814                         </varlistentry>
 815
 816                         <varlistentry>
 817                                 <term><command>mask [NAME...]</command></term>
 818
 819                                 <listitem><para>Mask one or more unit
 820                                 files, as specified on the command
 821                                 line. This will link these units to
 822                                 <filename>/dev/null</filename>, making
 823                                 it impossible to start them. This is a stronger version
 824                                 of <command>disable</command>, since
 825                                 it prohibits all kinds of activation
 826                                 of the unit, including manual
 827                                 activation. Use this option with
 828                                 care.</para>
 829                                 </listitem>
 830                         </varlistentry>
 831
 832                         <varlistentry>
 833                                 <term><command>unmask [NAME...]</command></term>
 834
 835                                 <listitem><para>Unmask one or more
 836                                 unit files, as specified on the
 837                                 command line. This will undo the
 838                                 effect of
 839                                 <command>mask</command>.</para>
 840                                 </listitem>
 841                         </varlistentry>
 842
 843                         <varlistentry>
 844                                 <term><command>link [NAME...]</command></term>
 845
 846                                 <listitem><para>Link a unit file that
 847                                 is not in the unit file search paths
 848                                 into the unit file search path. This
 849                                 requires an absolute path to a unit
 850                                 file. The effect of this can be undone
 851                                 with <command>disable</command>. The
 852                                 effect of this command is that a unit
 853                                 file is available for
 854                                 <command>start</command> and other
 855                                 commands although it isn't installed
 856                                 directly in the unit search
 857                                 path.</para>
 858                                 </listitem>
 859                         </varlistentry>
 860
 861                         <varlistentry>
 862                                 <term><command>load [NAME...]</command></term>
 863
 864                                 <listitem><para>Load one or more units
 865                                 specified on the command line. This
 866                                 will simply load their configuration
 867                                 from disk, but not start them. To
 868                                 start them you need to use the
 869                                 <command>start</command> command which
 870                                 will implicitly load a unit that has
 871                                 not been loaded yet. Note that systemd
 872                                 garbage collects loaded units that are
 873                                 not active or referenced by an active
 874                                 unit. This means that units loaded
 875                                 this way will usually not stay loaded
 876                                 for long. Also note that this command
 877                                 cannot be used to reload unit
 878                                 configuration. Use the
 879                                 <command>daemon-reload</command>
 880                                 command for that. All in all, this
 881                                 command is of little use except for
 882                                 debugging.</para>
 883                                 <para>This command should not be
 884                                 confused with the
 885                                 <command>daemon-reload</command> or
 886                                 <command>reload</command>
 887                                 commands.</para></listitem>
 888                         </varlistentry>
 889                         <varlistentry>
 890                                 <term><command>list-jobs</command></term>
 891
 892                                 <listitem><para>List jobs that are in progress.</para></listitem>
 893                         </varlistentry>
 894                         <varlistentry>
 895                                 <term><command>cancel [JOB...]</command></term>
 896
 897                                 <listitem><para>Cancel one or more
 898                                 jobs specified on the command line by
 899                                 their numeric job
 900                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 901                         </varlistentry>
 902                         <varlistentry>
 903                                 <term><command>dump</command></term>
 904
 905                                 <listitem><para>Dump server
 906                                 status. This will output a (usually
 907                                 very long) human readable manager
 908                                 status dump. Its format is subject to
 909                                 change without notice and should not
 910                                 be parsed by
 911                                 applications.</para></listitem>
 912                         </varlistentry>
 913                         <varlistentry>
 914                                 <term><command>dot</command></term>
 915
 916                                 <listitem><para>Generate textual
 917                                 dependency graph description in dot
 918                                 format for further processing with the
 919                                 GraphViz
 920                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 921                                 tool. Use a command line like
 922                                 <command>systemctl dot | dot -Tsvg >
 923                                 systemd.svg</command> to generate a
 924                                 graphical dependency tree. Unless
 925                                 <option>--order</option> or
 926                                 <option>--require</option> is passed
 927                                 the generated graph will show both
 928                                 ordering and requirement
 929                                 dependencies.</para></listitem>
 930                         </varlistentry>
 931                         <varlistentry>
 932                                 <term><command>snapshot [NAME]</command></term>
 933
 934                                 <listitem><para>Create a snapshot. If
 935                                 a snapshot name is specified, the new
 936                                 snapshot will be named after it. If
 937                                 none is specified an automatic
 938                                 snapshot name is generated. In either
 939                                 case, the snapshot name used is
 940                                 printed to STDOUT, unless
 941                                 <option>--quiet</option> is
 942                                 specified.</para>
 943
 944                                 <para>A snapshot refers to a saved
 945                                 state of the systemd manager. It is
 946                                 implemented itself as a unit that is
 947                                 generated dynamically with this
 948                                 command and has dependencies on all
 949                                 units active at the time. At a later
 950                                 time the user may return to this state
 951                                 by using the
 952                                 <command>isolate</command> command on
 953                                 the snapshot unit.</para></listitem>
 954
 955                                 <para>Snapshots are only useful for
 956                                 saving and restoring which units are
 957                                 running or are stopped, they do not
 958                                 save/restore any other
 959                                 state. Snapshots are dynamic and lost
 960                                 on reboot.</para>
 961                         </varlistentry>
 962                         <varlistentry>
 963                                 <term><command>delete [NAME...]</command></term>
 964
 965                                 <listitem><para>Remove a snapshot
 966                                 previously created with
 967                                 <command>snapshot</command>.</para></listitem>
 968                         </varlistentry>
 969                         <varlistentry>
 970                                 <term><command>daemon-reload</command></term>
 971
 972                                 <listitem><para>Reload systemd manager
 973                                 configuration. This will reload all
 974                                 unit files and recreate the entire
 975                                 dependency tree. While the daemon is
 976                                 reloaded, all sockets systemd listens
 977                                 on on behalf of user configuration will
 978                                 stay accessible.</para> <para>This
 979                                 command should not be confused with
 980                                 the <command>load</command> or
 981                                 <command>reload</command>
 982                                 commands.</para></listitem>
 983                         </varlistentry>
 984                         <varlistentry>
 985                                 <term><command>daemon-reexec</command></term>
 986
 987                                 <listitem><para>Reexecute the systemd
 988                                 manager. This will serialize the
 989                                 manager state, reexecute the process
 990                                 and deserialize the state again. This
 991                                 command is of little use except for
 992                                 debugging and package
 993                                 upgrades. Sometimes it might be
 994                                 helpful as a heavy-weight
 995                                 <command>daemon-reload</command>. While
 996                                 the daemon is reexecuted all sockets
 997                                 systemd listens on on behalf of user
 998                                 configuration will stay
 999                                 accessible.</para></listitem>
1000                         </varlistentry>
1001                         <varlistentry>
1002                                 <term><command>show-environment</command></term>
1003
1004                                 <listitem><para>Dump the systemd
1005                                 manager environment block. The
1006                                 environment block will be dumped in
1007                                 straight-forward form suitable for
1008                                 sourcing into a shell script. This
1009                                 environment block will be passed to
1010                                 all processes the manager
1011                                 spawns.</para></listitem>
1012                         </varlistentry>
1013                         <varlistentry>
1014                                 <term><command>set-environment [NAME=VALUE...]</command></term>
1015
1016                                 <listitem><para>Set one or more
1017                                 systemd manager environment variables,
1018                                 as specified on the command
1019                                 line.</para></listitem>
1020                         </varlistentry>
1021                         <varlistentry>
1022                                 <term><command>unset-environment [NAME...]</command></term>
1023
1024                                 <listitem><para>Unset one or more
1025                                 systemd manager environment
1026                                 variables. If only a variable name is
1027                                 specified it will be removed
1028                                 regardless of its value. If a variable
1029                                 and a value are specified the variable
1030                                 is only removed if it has the
1031                                 specified value.</para></listitem>
1032                         </varlistentry>
1033                         <varlistentry>
1034                                 <term><command>default</command></term>
1035
1036                                 <listitem><para>Enter default
1037                                 mode. This is mostly equivalent to
1038                                 <command>start
1039                                 default.target</command>.</para></listitem>
1040                         </varlistentry>
1041                         <varlistentry>
1042                                 <term><command>rescue</command></term>
1043
1044                                 <listitem><para>Enter rescue
1045                                 mode. This is mostly equivalent to
1046                                 <command>isolate
1047                                 rescue.target</command> but also
1048                                 prints a wall message to all
1049                                 users.</para></listitem>
1050                         </varlistentry>
1051                         <varlistentry>
1052                                 <term><command>emergency</command></term>
1053
1054                                 <listitem><para>Enter emergency
1055                                 mode. This is mostly equivalent to
1056                                 <command>isolate
1057                                 emergency.target</command> but also
1058                                 prints a wall message to all
1059                                 users.</para></listitem>
1060                         </varlistentry>
1061                         <varlistentry>
1062                                 <term><command>halt</command></term>
1063
1064                                 <listitem><para>Shut down and halt the
1065                                 system. This is mostly equivalent to
1066                                 <command>start halt.target</command>
1067                                 but also prints a wall message to all
1068                                 users.  If combined with
1069                                 <option>--force</option> shutdown of
1070                                 all running services is skipped,
1071                                 however all processes are killed and
1072                                 all file systems are unmounted or
1073                                 mounted read-only, immediately
1074                                 followed by the system halt.  If
1075                                 <option>--force</option> is specified
1076                                 twice the the operation is immediately
1077                                 executed without terminating any
1078                                 processes or unmounting any file
1079                                 systems. This may result in data
1080                                 loss.</para></listitem>
1081                         </varlistentry>
1082                         <varlistentry>
1083                                 <term><command>poweroff</command></term>
1084
1085                                 <listitem><para>Shut down and
1086                                 power-off the system. This is mostly
1087                                 equivalent to <command>start
1088                                 poweroff.target</command> but also
1089                                 prints a wall message to all users. If
1090                                 combined with <option>--force</option>
1091                                 shutdown of all running services is
1092                                 skipped, however all processes are
1093                                 killed and all file systems are
1094                                 unmounted or mounted read-only,
1095                                 immediately followed by the powering
1096                                 off. If <option>--force</option> is
1097                                 specified twice the the operation is
1098                                 immediately executed without
1099                                 terminating any processes or
1100                                 unmounting any file systems. This may
1101                                 result in data loss.</para></listitem>
1102                         </varlistentry>
1103                         <varlistentry>
1104                                 <term><command>reboot</command></term>
1105
1106                                 <listitem><para>Shut down and reboot
1107                                 the system. This is mostly equivalent
1108                                 to <command>start
1109                                 reboot.target</command> but also
1110                                 prints a wall message to all users. If
1111                                 combined with <option>--force</option>
1112                                 shutdown of all running services is
1113                                 skipped, however all processes are
1114                                 killed and all file systems are
1115                                 unmounted or mounted read-only,
1116                                 immediately followed by the reboot. If
1117                                 <option>--force</option> is specified
1118                                 twice the the operation is immediately
1119                                 executed without terminating any
1120                                 processes or unmounting any file
1121                                 systems. This may result in data
1122                                 loss.</para></listitem>
1123                         </varlistentry>
1124                         <varlistentry>
1125                                 <term><command>kexec</command></term>
1126
1127                                 <listitem><para>Shut down and reboot
1128                                 the system via kexec. This is mostly
1129                                 equivalent to <command>start
1130                                 kexec.target</command> but also prints
1131                                 a wall message to all users. If
1132                                 combined with <option>--force</option>
1133                                 shutdown of all running services is
1134                                 skipped, however all processes are killed
1135                                 and all file systems are unmounted or
1136                                 mounted read-only, immediately
1137                                 followed by the
1138                                 reboot.</para></listitem>
1139                         </varlistentry>
1140                         <varlistentry>
1141                                 <term><command>exit</command></term>
1142
1143                                 <listitem><para>Ask the systemd
1144                                 manager to quit. This is only
1145                                 supported for user service managers
1146                                 (i.e. in conjunction with the
1147                                 <option>--user</option> option) and
1148                                 will fail otherwise.</para></listitem>
1149                         </varlistentry>
1150                 </variablelist>
1151
1152         </refsect1>
1153
1154         <refsect1>
1155                 <title>Exit status</title>
1156
1157                 <para>On success 0 is returned, a non-zero failure
1158                 code otherwise.</para>
1159         </refsect1>
1160
1161         <refsect1>
1162                 <title>Environment</title>
1163
1164                 <variablelist>
1165                         <varlistentry>
1166                                 <term><varname>$SYSTEMD_PAGER</varname></term>
1167                                 <listitem><para>Pager to use when
1168                                 <option>--no-pager</option> is not given;
1169                                 overrides <varname>$PAGER</varname>.  Setting
1170                                 this to an empty string or the value
1171                                 <literal>cat</literal> is equivalent to passing
1172                                 <option>--no-pager</option>.</para></listitem>
1173                         </varlistentry>
1174                 </variablelist>
1175         </refsect1>
1176
1177         <refsect1>
1178                 <title>See Also</title>
1179                 <para>
1180                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1181                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1182                         <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1183                         <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1184                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1185                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1186                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
1187                 </para>
1188         </refsect1>
1189
1190 </refentry>