man/systemctl.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4
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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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  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  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/>.
  22 -->
  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                 <refname>systemd-systemctl</refname>
  48                 <refpurpose>Control the systemd system and service manager</refpurpose>
  49         </refnamediv>
  50
  51         <refsynopsisdiv>
  52                 <cmdsynopsis>
  53                         <command>systemctl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg> <arg choice="opt" rep="repeat">NAME</arg></command>
  54                 </cmdsynopsis>
  55         </refsynopsisdiv>
  56
  57         <refsect1>
  58                 <title>Description</title>
  59
  60                 <para><command>systemctl</command> may be used to
  61                 introspect and control the state of the
  62                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  63                 system and service manager.</para>
  64         </refsect1>
  65
  66         <refsect1>
  67                 <title>Options</title>
  68
  69                 <para>The following options are understood:</para>
  70
  71                 <variablelist>
  72                         <varlistentry>
  73                                 <term><option>--help</option></term>
  74                                 <term><option>-h</option></term>
  75
  76                                 <listitem><para>Prints a short help
  77                                 text and exits.</para></listitem>
  78                         </varlistentry>
  79
  80                         <varlistentry>
  81                                 <term><option>--version</option></term>
  82
  83                                 <listitem><para>Prints a short version
  84                                 string and exits.</para></listitem>
  85                         </varlistentry>
  86
  87                         <varlistentry>
  88                                 <term><option>--type=</option></term>
  89                                 <term><option>-t</option></term>
  90
  91                                 <listitem><para>When listing units,
  92                                 limit display to certain unit
  93                                 types. If not specified units of all
  94                                 types will be shown. The argument
  95                                 should be a unit type name such as
  96                                 <option>service</option>,
  97                                 <option>socket</option> and
  98                                 similar.</para></listitem>
  99                         </varlistentry>
 100
 101                         <varlistentry>
 102                                 <term><option>--property=</option></term>
 103                                 <term><option>-p</option></term>
 104
 105                                 <listitem><para>When showing
 106                                 unit/job/manager properties, limit
 107                                 display to certain properties as
 108                                 specified as argument. If not
 109                                 specified all set properties are
 110                                 shown. The argument should be a
 111                                 property name, such as
 112                                 <literal>MainPID</literal>. If
 113                                 specified more than once all
 114                                 properties with the specified names
 115                                 are shown.</para></listitem>
 116                         </varlistentry>
 117
 118                         <varlistentry>
 119                                 <term><option>--all</option></term>
 120                                 <term><option>-a</option></term>
 121
 122                                 <listitem><para>When listing units,
 123                                 show all units, regardless of their
 124                                 state, including inactive units. When
 125                                 showing unit/job/manager properties,
 126                                 show all properties regardless whether
 127                                 they are set or not.</para></listitem>
 128                         </varlistentry>
 129
 130                         <varlistentry>
 131                                 <term><option>--failed</option></term>
 132
 133                                 <listitem><para>When listing units,
 134                                 show only failed units. Do not confuse
 135                                 with
 136                                 <option>--fail</option>.</para></listitem>
 137                         </varlistentry>
 138
 139                         <varlistentry>
 140                                 <term><option>--full</option></term>
 141
 142                                 <listitem><para>Do not ellipsize unit
 143                                 names and truncate unit descriptions
 144                                 in the output of
 145                                 <command>list-units</command> and
 146                                 <command>list-jobs</command>.</para></listitem>
 147                         </varlistentry>
 148
 149                         <varlistentry>
 150                                 <term><option>--fail</option></term>
 151
 152                                 <listitem><para>If the requested
 153                                 operation conflicts with a pending
 154                                 unfinished job, fail the command. If
 155                                 this is not specified the requested
 156                                 operation will replace the pending job,
 157                                 if necessary. Do not confuse
 158                                 with
 159                                 <option>--failed</option>.</para></listitem>
 160                         </varlistentry>
 161
 162                         <varlistentry>
 163                                 <term><option>--ignore-dependencies</option></term>
 164
 165                                 <listitem><para>When enqueuing a new
 166                                 job ignore all its dependencies and
 167                                 execute it immediately. If passed no
 168                                 required units of the unit passed will
 169                                 be pulled in, and no ordering
 170                                 dependencies will be honoured. This is
 171                                 mostly a debugging and rescue tool for
 172                                 the administrator and should not be
 173                                 used by
 174                                 applications.</para></listitem>
 175                         </varlistentry>
 176
 177                         <varlistentry>
 178                                 <term><option>--quiet</option></term>
 179                                 <term><option>-q</option></term>
 180
 181                                 <listitem><para>Suppress output to
 182                                 STDOUT in
 183                                 <command>snapshot</command>,
 184                                 <command>is-active</command>,
 185                                 <command>enable</command> and
 186                                 <command>disable</command>.</para></listitem>
 187                         </varlistentry>
 188
 189                         <varlistentry>
 190                                 <term><option>--no-block</option></term>
 191
 192                                 <listitem><para>Do not synchronously wait for
 193                                 the requested operation to finish. If this is
 194                                 not specified the job will be verified,
 195                                 enqueued and <command>systemctl</command> will
 196                                 wait until it is completed. By passing this
 197                                 argument it is only verified and
 198                                 enqueued.</para></listitem>
 199                         </varlistentry>
 200
 201                         <varlistentry>
 202                                 <term><option>--no-legend</option></term>
 203
 204                                 <listitem><para>Do not print a legend, i.e.
 205                                 the column headers and the footer with hints.
 206                                 </para></listitem>
 207                         </varlistentry>
 208
 209                         <varlistentry>
 210                                 <term><option>--no-pager</option></term>
 211
 212                                 <listitem><para>Do not pipe output into a
 213                                 pager.</para></listitem>
 214                         </varlistentry>
 215
 216                         <varlistentry>
 217                                 <term><option>--system</option></term>
 218
 219                                 <listitem><para>Talk to the systemd
 220                                 system manager. (Default)</para></listitem>
 221                         </varlistentry>
 222
 223                         <varlistentry>
 224                                 <term><option>--user</option></term>
 225
 226                                 <listitem><para>Talk to the systemd
 227                                 manager of the calling user.</para></listitem>
 228                         </varlistentry>
 229
 230                         <varlistentry>
 231                                 <term><option>--order</option></term>
 232                                 <term><option>--require</option></term>
 233
 234                                 <listitem><para>When used in
 235                                 conjunction with the
 236                                 <command>dot</command> command (see
 237                                 below), selects which dependencies are
 238                                 shown in the dependency graph. If
 239                                 <option>--order</option> is passed
 240                                 only dependencies of type
 241                                 <varname>After=</varname> or
 242                                 <varname>Before=</varname> are
 243                                 shown. If <option>--require</option>
 244                                 is passed only dependencies of type
 245                                 <varname>Requires=</varname>,
 246                                 <varname>RequiresOverridable=</varname>,
 247                                 <varname>Requisite=</varname>,
 248                                 <varname>RequisiteOverridable=</varname>,
 249                                 <varname>Wants=</varname> and
 250                                 <varname>Conflicts=</varname> are
 251                                 shown. If neither is passed, shows
 252                                 dependencies of all these
 253                                 types.</para></listitem>
 254                         </varlistentry>
 255
 256                         <varlistentry>
 257                                 <term><option>--no-wall</option></term>
 258
 259                                 <listitem><para>Don't send wall
 260                                 message before
 261                                 halt, power-off, reboot.</para></listitem>
 262                         </varlistentry>
 263
 264                         <varlistentry>
 265                                 <term><option>--global</option></term>
 266
 267                                 <listitem><para>When used with
 268                                 <command>enable</command> and
 269                                 <command>disable</command>, operate on the
 270                                 global user configuration
 271                                 directory, thus enabling or disabling
 272                                 a unit file globally for all future
 273                                 logins of all users.</para></listitem>
 274                         </varlistentry>
 275
 276                         <varlistentry>
 277                                 <term><option>--no-reload</option></term>
 278
 279                                 <listitem><para>When used with
 280                                 <command>enable</command> and
 281                                 <command>disable</command>, do not
 282                                 implicitly reload daemon configuration
 283                                 after executing the
 284                                 changes.</para></listitem>
 285                         </varlistentry>
 286
 287                         <varlistentry>
 288                                 <term><option>--no-ask-password</option></term>
 289
 290                                 <listitem><para>When used with
 291                                 <command>start</command> and related
 292                                 commands, disables asking for
 293                                 passwords. Background services may
 294                                 require input of a password or
 295                                 passphrase string, for example to
 296                                 unlock system hard disks or
 297                                 cryptographic certificates. Unless
 298                                 this option is specified and the
 299                                 command is invoked from a terminal
 300                                 <command>systemctl</command> will
 301                                 query the user on the terminal for the
 302                                 necessary secrets. Use this option to
 303                                 switch this behavior off. In this
 304                                 case the password must be supplied by
 305                                 some other means (for example
 306                                 graphical password agents) or the
 307                                 service might fail.</para></listitem>
 308                         </varlistentry>
 309
 310                         <varlistentry>
 311                                 <term><option>--kill-who=</option></term>
 312
 313                                 <listitem><para>When used with
 314                                 <command>kill</command>, choose which
 315                                 processes to kill. Must be one of
 316                                 <option>main</option>,
 317                                 <option>control</option> or
 318                                 <option>all</option> to select whether
 319                                 to kill only the main process of the
 320                                 unit, the control process or all
 321                                 processes of the unit. If omitted
 322                                 defaults to
 323                                 <option>all</option>.</para></listitem>
 324                         </varlistentry>
 325
 326                         <varlistentry>
 327                                 <term><option>--signal=</option></term>
 328                                 <term><option>-s</option></term>
 329
 330                                 <listitem><para>When used with
 331                                 <command>kill</command>, choose which
 332                                 signal to send to selected
 333                                 processes. Must be one of the well
 334                                 known signal specifiers such as
 335                                 SIGTERM, SIGINT or SIGSTOP. If
 336                                 omitted defaults to
 337                                 <option>SIGTERM</option>.</para></listitem>
 338                         </varlistentry>
 339
 340                         <varlistentry>
 341                                 <term><option>--force</option></term>
 342                                 <term><option>-f</option></term>
 343
 344                                 <listitem><para>When used with
 345                                 <command>enable</command>, override any
 346                                 existing conflicting
 347                                 symlinks.</para></listitem>
 348
 349                                 <listitem><para>When used with
 350                                 <command>halt</command>,
 351                                 <command>poweroff</command>,
 352                                 <command>reboot</command> or
 353                                 <command>kexec</command> execute the
 354                                 selected operation without shutting
 355                                 down all units. However, all processes
 356                                 will be killed forcibly and all file
 357                                 systems are unmounted or remounted
 358                                 read-only. This is hence a drastic but
 359                                 relatively safe option to request an
 360                                 immediate reboot. If
 361                                 <option>--force</option> is specified
 362                                 twice for these operations, they will
 363                                 be executed immediately without
 364                                 terminating any processes or umounting
 365                                 any file systems. Warning: specifying
 366                                 <option>--force</option> twice with
 367                                 any of these operations might result
 368                                 in data loss.</para></listitem>
 369                         </varlistentry>
 370
 371                         <varlistentry>
 372                                 <term><option>--root=</option></term>
 373
 374                                 <listitem><para>When used with
 375                                 <command>enable</command>/<command>disable</command>/<command>is-enabled</command> (and
 376                                 related commands), use alternative
 377                                 root path when looking for unit
 378                                 files.</para></listitem>
 379                         </varlistentry>
 380
 381                         <varlistentry>
 382                                 <term><option>--runtime</option></term>
 383
 384                                 <listitem><para>When used with
 385                                 <command>enable</command>/<command>disable</command>/<command>is-enabled</command> (and related commands), make
 386                                 changes only temporarily, so that they
 387                                 are dropped on the next reboot. This
 388                                 will have the effect that changes are
 389                                 not made in subdirectories of
 390                                 <filename>/etc</filename> but in
 391                                 <filename>/run</filename>, with
 392                                 identical immediate effects, however,
 393                                 since the latter is lost on reboot,
 394                                 the changes are lost
 395                                 too.</para></listitem>
 396                         </varlistentry>
 397
 398                         <varlistentry>
 399                                 <term><option>-H</option></term>
 400                                 <term><option>--host</option></term>
 401
 402                                 <listitem><para>Execute operation
 403                                 remotely. Specify a hostname, or
 404                                 username and hostname separated by @,
 405                                 to connect to. This will use SSH to
 406                                 talk to the remote systemd
 407                                 instance.</para></listitem>
 408                         </varlistentry>
 409
 410                         <varlistentry>
 411                                 <term><option>-P</option></term>
 412                                 <term><option>--privileged</option></term>
 413
 414                                 <listitem><para>Acquire privileges via
 415                                 PolicyKit before executing the
 416                                 operation.</para></listitem>
 417                         </varlistentry>
 418
 419                         <varlistentry>
 420                                 <term><option>--lines=</option></term>
 421                                 <term><option>-n</option></term>
 422
 423                                 <listitem><para>When used with
 424                                 <command>status</command> controls the
 425                                 number of journal lines to show,
 426                                 counting from the most recent
 427                                 ones. Takes a positive integer
 428                                 argument. Defaults to
 429                                 10.</para></listitem>
 430                         </varlistentry>
 431
 432                         <varlistentry>
 433                                 <term><option>--follow</option></term>
 434                                 <term><option>-f</option></term>
 435
 436                                 <listitem><para>When used with
 437                                 <command>status</command> continously
 438                                 prints new journal entries as they are
 439                                 appended to the
 440                                 journal.</para></listitem>
 441                         </varlistentry>
 442
 443                         <varlistentry>
 444                                 <term><option>--output=</option></term>
 445                                 <term><option>-o</option></term>
 446
 447                                 <listitem><para>When used with
 448                                 <command>status</command> controls the
 449                                 formatting of the journal entries that
 450                                 are shown. For the available choices
 451                                 see
 452                                 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. Defaults
 453                                 to
 454                                 <literal>short</literal>.</para></listitem>
 455                         </varlistentry>
 456
 457                 </variablelist>
 458
 459                 <para>The following commands are understood:</para>
 460
 461                 <variablelist>
 462                         <varlistentry>
 463                                 <term><command>list-units</command></term>
 464
 465                                 <listitem><para>List known units.</para></listitem>
 466                         </varlistentry>
 467                         <varlistentry>
 468                                 <term><command>start [NAME...]</command></term>
 469
 470                                 <listitem><para>Start (activate) one
 471                                 or more units specified on the command
 472                                 line.</para></listitem>
 473                         </varlistentry>
 474                         <varlistentry>
 475                                 <term><command>stop [NAME...]</command></term>
 476
 477                                 <listitem><para>Stop (deactivate) one
 478                                 or more units specified on the command
 479                                 line.</para></listitem>
 480                         </varlistentry>
 481                         <varlistentry>
 482                                 <term><command>reload [NAME...]</command></term>
 483
 484                                 <listitem><para>Asks all units listed
 485                                 on the command line to reload their
 486                                 configuration. Note that this will
 487                                 reload the service-specific
 488                                 configuration, not the unit
 489                                 configuration file of systemd. If you
 490                                 want systemd to reload the
 491                                 configuration file of a unit use the
 492                                 <command>daemon-reload</command>
 493                                 command. In other words: for the
 494                                 example case of Apache, this will
 495                                 reload Apache's
 496                                 <filename>httpd.conf</filename> in the
 497                                 web server, not the
 498                                 <filename>apache.service</filename>
 499                                 systemd unit file. </para>
 500
 501                                 <para>This command should not be
 502                                 confused with the
 503                                 <command>daemon-reload</command> or
 504                                 <command>load</command>
 505                                 commands.</para></listitem>
 506
 507                         </varlistentry>
 508                         <varlistentry>
 509                                 <term><command>restart [NAME...]</command></term>
 510
 511                                 <listitem><para>Restart one or more
 512                                 units specified on the command
 513                                 line. If the units are not running yet
 514                                 they will be
 515                                 started.</para></listitem>
 516                         </varlistentry>
 517                         <varlistentry>
 518                                 <term><command>try-restart [NAME...]</command></term>
 519
 520                                 <listitem><para>Restart one or more
 521                                 units specified on the command
 522                                 line if the units are running. Do
 523                                 nothing if units are not running.
 524                                 Note that for compatibility
 525                                 with Red Hat init scripts
 526                                 <command>condrestart</command> is
 527                                 equivalent to this command.</para></listitem>
 528                         </varlistentry>
 529                         <varlistentry>
 530                                 <term><command>reload-or-restart [NAME...]</command></term>
 531
 532                                 <listitem><para>Reload one or more
 533                                 units if they support it. If not,
 534                                 restart them instead. If the units
 535                                 are not running yet they will be
 536                                 started.</para></listitem>
 537                         </varlistentry>
 538                         <varlistentry>
 539                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 540
 541                                 <listitem><para>Reload one or more
 542                                 units if they support it. If not,
 543                                 restart them instead. Do nothing if
 544                                 the units are not running. Note that
 545                                 for compatibility with SysV init
 546                                 scripts
 547                                 <command>force-reload</command> is
 548                                 equivalent to this
 549                                 command.</para></listitem>
 550                         </varlistentry>
 551                         <varlistentry>
 552                                 <term><command>isolate [NAME]</command></term>
 553
 554                                 <listitem><para>Start the unit
 555                                 specified on the command line and its
 556                                 dependencies and stop all others.</para>
 557
 558                                 <para>This is similar to changing the
 559                                 runlevel in a traditional init system. The
 560                                 <command>isolate</command> command will
 561                                 immediately stop processes that are not
 562                                 enabled in the new unit, possibly including
 563                                 the graphical environment or terminal you
 564                                 are currently using.</para>
 565
 566                                 <para>Note that this works only on units
 567                                 where <option>AllowIsolate=</option> is
 568                                 enabled. See
 569                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 570                                 for details.</para></listitem>
 571                         </varlistentry>
 572                         <varlistentry>
 573                                 <term><command>kill [NAME...]</command></term>
 574
 575                                 <listitem><para>Send a signal to one
 576                                 or more processes of the unit. Use
 577                                 <option>--kill-who=</option> to select
 578                                 which process to kill. Use
 579                                 <option>--kill-mode=</option> to
 580                                 select the kill mode and
 581                                 <option>--signal=</option> to select
 582                                 the signal to send.</para></listitem>
 583                         </varlistentry>
 584                         <varlistentry>
 585                                 <term><command>is-active [NAME...]</command></term>
 586
 587                                 <listitem><para>Check whether any of
 588                                 the specified units are active
 589                                 (i.e. running). Returns an exit code
 590                                 0 if at least one is active, non-zero
 591                                 otherwise. Unless
 592                                 <option>--quiet</option> is specified
 593                                 this will also print the current unit
 594                                 state to STDOUT.</para></listitem>
 595                         </varlistentry>
 596                         <varlistentry>
 597                                 <term><command>status [NAME...|PID...]</command></term>
 598
 599                                 <listitem><para>Show terse runtime
 600                                 status information about one or more
 601                                 units, followed by its most recent log
 602                                 data from the journal. This function
 603                                 is intended to generate human-readable
 604                                 output. If you are looking for
 605                                 computer-parsable output, use
 606                                 <command>show</command> instead. If a
 607                                 PID is passed information about the
 608                                 unit the process of the PID belongs to
 609                                 is shown.</para></listitem>
 610                         </varlistentry>
 611                         <varlistentry>
 612                                 <term><command>show [NAME...|JOB...]</command></term>
 613
 614                                 <listitem><para>Show properties of one
 615                                 or more units, jobs or the manager
 616                                 itself. If no argument is specified
 617                                 properties of the manager will be
 618                                 shown. If a unit name is specified
 619                                 properties of the unit is shown, and
 620                                 if a job id is specified properties of
 621                                 the job is shown. By default, empty
 622                                 properties are suppressed. Use
 623                                 <option>--all</option> to show those
 624                                 too. To select specific properties to
 625                                 show use
 626                                 <option>--property=</option>. This
 627                                 command is intended to be used
 628                                 whenever computer-parsable output is
 629                                 required. Use
 630                                 <command>status</command> if you are
 631                                 looking for formatted human-readable
 632                                 output.</para></listitem>
 633                         </varlistentry>
 634
 635                         <varlistentry>
 636                                 <term><command>reset-failed [NAME...]</command></term>
 637
 638                                 <listitem><para>Reset the
 639                                 '<literal>failed</literal>' state of the
 640                                 specified units, or if no unit name is
 641                                 passed of all units. When a unit fails
 642                                 in some way (i.e. process exiting with
 643                                 non-zero error code, terminating
 644                                 abnormally or timing out) it will
 645                                 automatically enter the
 646                                 '<literal>failed</literal>' state and
 647                                 its exit code and status is recorded
 648                                 for introspection by the administrator
 649                                 until the service is restarted or
 650                                 reset with this
 651                                 command.</para></listitem>
 652                         </varlistentry>
 653
 654                         <varlistentry>
 655                                 <term><command>list-unit-files</command></term>
 656
 657                                 <listitem><para>List installed unit files.
 658                                 </para></listitem>
 659                         </varlistentry>
 660
 661                         <varlistentry>
 662                                 <term><command>enable [NAME...]</command></term>
 663
 664                                 <listitem><para>Enable one or more
 665                                 unit files, as specified on the
 666                                 command line. This will create a
 667                                 number of symlinks as encoded in the
 668                                 <literal>[Install]</literal> sections
 669                                 of the unit files. After the symlinks
 670                                 have been created the systemd
 671                                 configuration is reloaded (in a way
 672                                 that is equivalent to
 673                                 <command>daemon-reload</command>) to
 674                                 ensure the changes are taken into
 675                                 account immediately. Note that this
 676                                 does not have the effect that any of
 677                                 the units enabled are also started at
 678                                 the same time. If this is desired a
 679                                 separate <command>start</command>
 680                                 command must be invoked for the
 681                                 unit.</para>
 682
 683                                 <para>This command will
 684                                 print the actions executed. This
 685                                 output may be suppressed by passing
 686                                 <option>--quiet</option>.</para>
 687
 688                                 <para>Note that this operation creates
 689                                 only the suggested symlinks for the
 690                                 units. While this command is the
 691                                 recommended way to manipulate the unit
 692                                 configuration directory, the
 693                                 administrator is free to make
 694                                 additional changes manually, by
 695                                 placing or removing symlinks in the
 696                                 directory. This is particularly useful
 697                                 to create configurations that deviate
 698                                 from the suggested default
 699                                 installation. In this case the
 700                                 administrator must make sure to invoke
 701                                 <command>daemon-reload</command>
 702                                 manually as necessary, to ensure his
 703                                 changes are taken into account.</para>
 704
 705                                 <para>Enabling units should not be
 706                                 confused with starting (activating)
 707                                 units, as done by the
 708                                 <command>start</command>
 709                                 command. Enabling and starting units
 710                                 is orthogonal: units may be enabled
 711                                 without being started and started
 712                                 without being enabled. Enabling simply
 713                                 hooks the unit into various suggested
 714                                 places (for example, so that the unit
 715                                 is automatically started on boot or
 716                                 when a particular kind of hardware is
 717                                 plugged in). Starting actually spawns
 718                                 the daemon process (in case of service
 719                                 units), or binds the socket (in case
 720                                 of socket units), and so
 721                                 on.</para>
 722
 723                                 <para>Depending on whether
 724                                 <option>--system</option>,
 725                                 <option>--user</option> or
 726                                 <option>--global</option> is specified
 727                                 this enables the unit for the system,
 728                                 for the calling user only
 729                                 or for all future logins of all
 730                                 users. Note that in the latter case no
 731                                 systemd daemon configuration is
 732                                 reloaded.</para>
 733                                 </listitem>
 734                         </varlistentry>
 735
 736                         <varlistentry>
 737                                 <term><command>disable [NAME...]</command></term>
 738
 739                                 <listitem><para>Disables one or more
 740                                 units. This removes all symlinks to
 741                                 the specified unit files from the unit
 742                                 configuration directory, and hence
 743                                 undoes the changes made by
 744                                 <command>enable</command>. Note
 745                                 however that this removes
 746                                 all symlinks to the unit files
 747                                 (i.e. including manual additions), not
 748                                 just those actually created by
 749                                 <command>enable</command>. This call
 750                                 implicitly reloads the systemd daemon
 751                                 configuration after completing the
 752                                 disabling of the units. Note that this
 753                                 command does not implicitly stop the
 754                                 units that is being disabled. If this
 755                                 is desired an additional
 756                                 <command>stop</command>command should
 757                                 be executed afterwards.</para>
 758
 759                                 <para>This command will print the
 760                                 actions executed. This output may be
 761                                 suppressed by passing
 762                                 <option>--quiet</option>.</para>
 763                                 </listitem>
 764
 765                                 <para>This command honors
 766                                 <option>--system</option>,
 767                                 <option>--user</option>,
 768                                 <option>--global</option> in a similar
 769                                 way as
 770                                 <command>enable</command>.</para>
 771                         </varlistentry>
 772
 773                         <varlistentry>
 774                                 <term><command>is-enabled [NAME...]</command></term>
 775
 776                                 <listitem><para>Checks whether any of
 777                                 the specified unit files is enabled
 778                                 (as with
 779                                 <command>enable</command>). Returns an
 780                                 exit code of 0 if at least one is
 781                                 enabled, non-zero otherwise. Prints
 782                                 the current enable status. To suppress
 783                                 this output use
 784                                 <option>--quiet</option>.</para></listitem>
 785                         </varlistentry>
 786
 787                         <varlistentry>
 788                                 <term><command>reenable [NAME...]</command></term>
 789
 790                                 <listitem><para>Reenable one or more
 791                                 unit files, as specified on the
 792                                 command line. This is a combination of
 793                                 <command>disable</command> and
 794                                 <command>enable</command> and is
 795                                 useful to reset the symlinks a unit is
 796                                 enabled with to the defaults
 797                                 configured in the
 798                                 <literal>[Install]</literal> section
 799                                 of the unit file.</para>
 800                                 </listitem>
 801                         </varlistentry>
 802
 803                         <varlistentry>
 804                                 <term><command>preset [NAME...]</command></term>
 805
 806                                 <listitem><para>Reset one or more unit
 807                                 files, as specified on the command
 808                                 line, to the defaults configured in a
 809                                 preset file. This has the same effect
 810                                 as <command>disable</command> or
 811                                 <command>enable</command>, depending
 812                                 how the unit is listed in the preset
 813                                 files.</para>
 814                                 </listitem>
 815                         </varlistentry>
 816
 817                         <varlistentry>
 818                                 <term><command>mask [NAME...]</command></term>
 819
 820                                 <listitem><para>Mask one or more unit
 821                                 files, as specified on the command
 822                                 line. This will link these units to
 823                                 <filename>/dev/null</filename>, making
 824                                 it impossible to start them. This is a stronger version
 825                                 of <command>disable</command>, since
 826                                 it prohibits all kinds of activation
 827                                 of the unit, including manual
 828                                 activation. Use this option with
 829                                 care.</para>
 830                                 </listitem>
 831                         </varlistentry>
 832
 833                         <varlistentry>
 834                                 <term><command>unmask [NAME...]</command></term>
 835
 836                                 <listitem><para>Unmask one or more
 837                                 unit files, as specified on the
 838                                 command line. This will undo the
 839                                 effect of
 840                                 <command>mask</command>.</para>
 841                                 </listitem>
 842                         </varlistentry>
 843
 844                         <varlistentry>
 845                                 <term><command>link [NAME...]</command></term>
 846
 847                                 <listitem><para>Link a unit file that
 848                                 is not in the unit file search paths
 849                                 into the unit file search path. This
 850                                 requires an absolute path to a unit
 851                                 file. The effect of this can be undone
 852                                 with <command>disable</command>. The
 853                                 effect of this command is that a unit
 854                                 file is available for
 855                                 <command>start</command> and other
 856                                 commands although it isn't installed
 857                                 directly in the unit search
 858                                 path.</para>
 859                                 </listitem>
 860                         </varlistentry>
 861
 862                         <varlistentry>
 863                                 <term><command>load [NAME...]</command></term>
 864
 865                                 <listitem><para>Load one or more units
 866                                 specified on the command line. This
 867                                 will simply load their configuration
 868                                 from disk, but not start them. To
 869                                 start them you need to use the
 870                                 <command>start</command> command which
 871                                 will implicitly load a unit that has
 872                                 not been loaded yet. Note that systemd
 873                                 garbage collects loaded units that are
 874                                 not active or referenced by an active
 875                                 unit. This means that units loaded
 876                                 this way will usually not stay loaded
 877                                 for long. Also note that this command
 878                                 cannot be used to reload unit
 879                                 configuration. Use the
 880                                 <command>daemon-reload</command>
 881                                 command for that. All in all, this
 882                                 command is of little use except for
 883                                 debugging.</para>
 884                                 <para>This command should not be
 885                                 confused with the
 886                                 <command>daemon-reload</command> or
 887                                 <command>reload</command>
 888                                 commands.</para></listitem>
 889                         </varlistentry>
 890                         <varlistentry>
 891                                 <term><command>list-jobs</command></term>
 892
 893                                 <listitem><para>List jobs that are in progress.</para></listitem>
 894                         </varlistentry>
 895                         <varlistentry>
 896                                 <term><command>cancel [JOB...]</command></term>
 897
 898                                 <listitem><para>Cancel one or more
 899                                 jobs specified on the command line by
 900                                 their numeric job
 901                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 902                         </varlistentry>
 903                         <varlistentry>
 904                                 <term><command>dump</command></term>
 905
 906                                 <listitem><para>Dump server
 907                                 status. This will output a (usually
 908                                 very long) human readable manager
 909                                 status dump. Its format is subject to
 910                                 change without notice and should not
 911                                 be parsed by
 912                                 applications.</para></listitem>
 913                         </varlistentry>
 914                         <varlistentry>
 915                                 <term><command>dot</command></term>
 916
 917                                 <listitem><para>Generate textual
 918                                 dependency graph description in dot
 919                                 format for further processing with the
 920                                 GraphViz
 921                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 922                                 tool. Use a command line like
 923                                 <command>systemctl dot | dot -Tsvg >
 924                                 systemd.svg</command> to generate a
 925                                 graphical dependency tree. Unless
 926                                 <option>--order</option> or
 927                                 <option>--require</option> is passed
 928                                 the generated graph will show both
 929                                 ordering and requirement
 930                                 dependencies.</para></listitem>
 931                         </varlistentry>
 932                         <varlistentry>
 933                                 <term><command>snapshot [NAME]</command></term>
 934
 935                                 <listitem><para>Create a snapshot. If
 936                                 a snapshot name is specified, the new
 937                                 snapshot will be named after it. If
 938                                 none is specified an automatic
 939                                 snapshot name is generated. In either
 940                                 case, the snapshot name used is
 941                                 printed to STDOUT, unless
 942                                 <option>--quiet</option> is
 943                                 specified.</para>
 944
 945                                 <para>A snapshot refers to a saved
 946                                 state of the systemd manager. It is
 947                                 implemented itself as a unit that is
 948                                 generated dynamically with this
 949                                 command and has dependencies on all
 950                                 units active at the time. At a later
 951                                 time the user may return to this state
 952                                 by using the
 953                                 <command>isolate</command> command on
 954                                 the snapshot unit.</para></listitem>
 955
 956                                 <para>Snapshots are only useful for
 957                                 saving and restoring which units are
 958                                 running or are stopped, they do not
 959                                 save/restore any other
 960                                 state. Snapshots are dynamic and lost
 961                                 on reboot.</para>
 962                         </varlistentry>
 963                         <varlistentry>
 964                                 <term><command>delete [NAME...]</command></term>
 965
 966                                 <listitem><para>Remove a snapshot
 967                                 previously created with
 968                                 <command>snapshot</command>.</para></listitem>
 969                         </varlistentry>
 970                         <varlistentry>
 971                                 <term><command>daemon-reload</command></term>
 972
 973                                 <listitem><para>Reload systemd manager
 974                                 configuration. This will reload all
 975                                 unit files and recreate the entire
 976                                 dependency tree. While the daemon is
 977                                 reloaded, all sockets systemd listens
 978                                 on on behalf of user configuration will
 979                                 stay accessible.</para> <para>This
 980                                 command should not be confused with
 981                                 the <command>load</command> or
 982                                 <command>reload</command>
 983                                 commands.</para></listitem>
 984                         </varlistentry>
 985                         <varlistentry>
 986                                 <term><command>daemon-reexec</command></term>
 987
 988                                 <listitem><para>Reexecute the systemd
 989                                 manager. This will serialize the
 990                                 manager state, reexecute the process
 991                                 and deserialize the state again. This
 992                                 command is of little use except for
 993                                 debugging and package
 994                                 upgrades. Sometimes it might be
 995                                 helpful as a heavy-weight
 996                                 <command>daemon-reload</command>. While
 997                                 the daemon is reexecuted all sockets
 998                                 systemd listens on on behalf of user
 999                                 configuration will stay
1000                                 accessible.</para></listitem>
1001                         </varlistentry>
1002                         <varlistentry>
1003                                 <term><command>show-environment</command></term>
1004
1005                                 <listitem><para>Dump the systemd
1006                                 manager environment block. The
1007                                 environment block will be dumped in
1008                                 straight-forward form suitable for
1009                                 sourcing into a shell script. This
1010                                 environment block will be passed to
1011                                 all processes the manager
1012                                 spawns.</para></listitem>
1013                         </varlistentry>
1014                         <varlistentry>
1015                                 <term><command>set-environment [NAME=VALUE...]</command></term>
1016
1017                                 <listitem><para>Set one or more
1018                                 systemd manager environment variables,
1019                                 as specified on the command
1020                                 line.</para></listitem>
1021                         </varlistentry>
1022                         <varlistentry>
1023                                 <term><command>unset-environment [NAME...]</command></term>
1024
1025                                 <listitem><para>Unset one or more
1026                                 systemd manager environment
1027                                 variables. If only a variable name is
1028                                 specified it will be removed
1029                                 regardless of its value. If a variable
1030                                 and a value are specified the variable
1031                                 is only removed if it has the
1032                                 specified value.</para></listitem>
1033                         </varlistentry>
1034                         <varlistentry>
1035                                 <term><command>default</command></term>
1036
1037                                 <listitem><para>Enter default
1038                                 mode. This is mostly equivalent to
1039                                 <command>start
1040                                 default.target</command>.</para></listitem>
1041                         </varlistentry>
1042                         <varlistentry>
1043                                 <term><command>rescue</command></term>
1044
1045                                 <listitem><para>Enter rescue
1046                                 mode. This is mostly equivalent to
1047                                 <command>isolate
1048                                 rescue.target</command> but also
1049                                 prints a wall message to all
1050                                 users.</para></listitem>
1051                         </varlistentry>
1052                         <varlistentry>
1053                                 <term><command>emergency</command></term>
1054
1055                                 <listitem><para>Enter emergency
1056                                 mode. This is mostly equivalent to
1057                                 <command>isolate
1058                                 emergency.target</command> but also
1059                                 prints a wall message to all
1060                                 users.</para></listitem>
1061                         </varlistentry>
1062                         <varlistentry>
1063                                 <term><command>halt</command></term>
1064
1065                                 <listitem><para>Shut down and halt the
1066                                 system. This is mostly equivalent to
1067                                 <command>start halt.target</command>
1068                                 but also prints a wall message to all
1069                                 users.  If combined with
1070                                 <option>--force</option> shutdown of
1071                                 all running services is skipped,
1072                                 however all processes are killed and
1073                                 all file systems are unmounted or
1074                                 mounted read-only, immediately
1075                                 followed by the system halt.  If
1076                                 <option>--force</option> is specified
1077                                 twice the the operation is immediately
1078                                 executed without terminating any
1079                                 processes or unmounting any file
1080                                 systems. This may result in data
1081                                 loss.</para></listitem>
1082                         </varlistentry>
1083                         <varlistentry>
1084                                 <term><command>poweroff</command></term>
1085
1086                                 <listitem><para>Shut down and
1087                                 power-off the system. This is mostly
1088                                 equivalent to <command>start
1089                                 poweroff.target</command> but also
1090                                 prints a wall message to all users. If
1091                                 combined with <option>--force</option>
1092                                 shutdown of all running services is
1093                                 skipped, however all processes are
1094                                 killed and all file systems are
1095                                 unmounted or mounted read-only,
1096                                 immediately followed by the powering
1097                                 off. If <option>--force</option> is
1098                                 specified twice the the operation is
1099                                 immediately executed without
1100                                 terminating any processes or
1101                                 unmounting any file systems. This may
1102                                 result in data loss.</para></listitem>
1103                         </varlistentry>
1104                         <varlistentry>
1105                                 <term><command>reboot</command></term>
1106
1107                                 <listitem><para>Shut down and reboot
1108                                 the system. This is mostly equivalent
1109                                 to <command>start
1110                                 reboot.target</command> but also
1111                                 prints a wall message to all users. If
1112                                 combined with <option>--force</option>
1113                                 shutdown of all running services is
1114                                 skipped, however all processes are
1115                                 killed and all file systems are
1116                                 unmounted or mounted read-only,
1117                                 immediately followed by the reboot. If
1118                                 <option>--force</option> is specified
1119                                 twice the the operation is immediately
1120                                 executed without terminating any
1121                                 processes or unmounting any file
1122                                 systems. This may result in data
1123                                 loss.</para></listitem>
1124                         </varlistentry>
1125                         <varlistentry>
1126                                 <term><command>kexec</command></term>
1127
1128                                 <listitem><para>Shut down and reboot
1129                                 the system via kexec. This is mostly
1130                                 equivalent to <command>start
1131                                 kexec.target</command> but also prints
1132                                 a wall message to all users. If
1133                                 combined with <option>--force</option>
1134                                 shutdown of all running services is
1135                                 skipped, however all processes are killed
1136                                 and all file systems are unmounted or
1137                                 mounted read-only, immediately
1138                                 followed by the
1139                                 reboot.</para></listitem>
1140                         </varlistentry>
1141                         <varlistentry>
1142                                 <term><command>exit</command></term>
1143
1144                                 <listitem><para>Ask the systemd
1145                                 manager to quit. This is only
1146                                 supported for user service managers
1147                                 (i.e. in conjunction with the
1148                                 <option>--user</option> option) and
1149                                 will fail otherwise.</para></listitem>
1150                         </varlistentry>
1151                 </variablelist>
1152
1153         </refsect1>
1154
1155         <refsect1>
1156                 <title>Exit status</title>
1157
1158                 <para>On success 0 is returned, a non-zero failure
1159                 code otherwise.</para>
1160         </refsect1>
1161
1162         <refsect1>
1163                 <title>Environment</title>
1164
1165                 <variablelist>
1166                         <varlistentry>
1167                                 <term><varname>$SYSTEMD_PAGER</varname></term>
1168                                 <listitem><para>Pager to use when
1169                                 <option>--no-pager</option> is not given;
1170                                 overrides <varname>$PAGER</varname>.  Setting
1171                                 this to an empty string or the value
1172                                 <literal>cat</literal> is equivalent to passing
1173                                 <option>--no-pager</option>.</para></listitem>
1174                         </varlistentry>
1175                 </variablelist>
1176         </refsect1>
1177
1178         <refsect1>
1179                 <title>See Also</title>
1180                 <para>
1181                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1182                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1183                         <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1184                         <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1185                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1186                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1187                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
1188                 </para>
1189         </refsect1>
1190
1191 </refentry>