man/systemd-run.xml

   1 <?xml version='1.0'?>
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   5
   6 <refentry id="systemd-run"
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>systemd-run</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>systemd-run</refentrytitle>
  16     <manvolnum>1</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>systemd-run</refname>
  21     <refpurpose>Run programs in transient scope units, service units, or path-, socket-, or timer-triggered service units</refpurpose>
  22   </refnamediv>
  23
  24   <refsynopsisdiv>
  25     <cmdsynopsis>
  26       <command>systemd-run</command>
  27       <arg choice="opt" rep="repeat">OPTIONS</arg>
  28       <arg choice="plain"><replaceable>COMMAND</replaceable>
  29       <arg choice="opt" rep="repeat">ARGS</arg>
  30       </arg>
  31     </cmdsynopsis>
  32     <cmdsynopsis>
  33       <command>systemd-run</command>
  34       <arg choice="opt" rep="repeat">OPTIONS</arg>
  35       <arg choice="opt" rep="repeat">PATH OPTIONS</arg>
  36       <arg choice="req"><replaceable>COMMAND</replaceable></arg>
  37       <arg choice="opt" rep="repeat">ARGS</arg>
  38     </cmdsynopsis>
  39     <cmdsynopsis>
  40       <command>systemd-run</command>
  41       <arg choice="opt" rep="repeat">OPTIONS</arg>
  42       <arg choice="opt" rep="repeat">SOCKET OPTIONS</arg>
  43       <arg choice="req"><replaceable>COMMAND</replaceable></arg>
  44       <arg choice="opt" rep="repeat">ARGS</arg>
  45     </cmdsynopsis>
  46     <cmdsynopsis>
  47       <command>systemd-run</command>
  48       <arg choice="opt" rep="repeat">OPTIONS</arg>
  49       <arg choice="opt" rep="repeat">TIMER OPTIONS</arg>
  50       <arg choice="req"><replaceable>COMMAND</replaceable></arg>
  51       <arg choice="opt" rep="repeat">ARGS</arg>
  52     </cmdsynopsis>
  53   </refsynopsisdiv>
  54
  55   <refsect1>
  56     <title>Description</title>
  57
  58     <para><command>systemd-run</command> may be used to create and start a transient <filename>.service</filename> or
  59     <filename>.scope</filename> unit and run the specified <replaceable>COMMAND</replaceable> in it. It may also be
  60     used to create and start a transient <filename>.path</filename>, <filename>.socket</filename>, or
  61     <filename>.timer</filename> unit, that activates a <filename>.service</filename> unit when elapsing.</para>
  62
  63     <para>If a command is run as transient service unit, it will be started and managed by the service manager like any
  64     other service, and thus shows up in the output of <command>systemctl list-units</command> like any other unit. It
  65     will run in a clean and detached execution environment, with the service manager as its parent process. In this
  66     mode, <command>systemd-run</command> will start the service asynchronously in the background and return after the
  67     command has begun execution (unless <option>--no-block</option> or <option>--wait</option> are specified, see
  68     below).</para>
  69
  70     <para>If a command is run as transient scope unit, it will be executed by <command>systemd-run</command> itself as
  71     parent process and will thus inherit the execution environment of the caller. However, the processes of the command
  72     are managed by the service manager similar to normal services, and will show up in the output of <command>systemctl
  73     list-units</command>. Execution in this case is synchronous, and will return only when the command finishes. This
  74     mode is enabled via the <option>--scope</option> switch (see below). </para>
  75
  76     <para>If a command is run with path, socket, or timer options such as <option>--on-calendar=</option> (see below),
  77     a transient path, socket, or timer unit is created alongside the service unit for the specified command. Only the
  78     transient path, socket, or timer unit is started immediately, the transient service unit will be triggered by the
  79     path, socket, or timer unit. If the <option>--unit=</option> option is specified, the
  80     <replaceable>COMMAND</replaceable> may be omitted. In this case, <command>systemd-run</command> creates only a
  81     <filename>.path</filename>, <filename>.socket</filename>, or <filename>.timer</filename> unit that triggers the
  82     specified unit.</para>
  83
  84     <para>By default, services created with <command>systemd-run</command> default to the <option>simple</option> type,
  85     see the description of <varname>Type=</varname> in
  86     <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
  87     details. Note that when this type is used the service manager (and thus the <command>systemd-run</command> command)
  88     considers service start-up successful as soon as the <function>fork()</function> for the main service process
  89     succeeded, i.e. before the <function>execve()</function> is invoked, and thus even if the specified command cannot
  90     be started. Consider using the <option>exec</option> service type (i.e. <option>--property=Type=exec</option>) to
  91     ensure that <command>systemd-run</command> returns successfully only if the specified command line has been
  92     successfully started.</para>
  93   </refsect1>
  94
  95   <refsect1>
  96     <title>Options</title>
  97
  98     <para>The following options are understood:</para>
  99
 100     <variablelist>
 101       <varlistentry>
 102         <term><option>--no-ask-password</option></term>
 103
 104         <listitem><para>Do not query the user for authentication for
 105         privileged operations.</para></listitem>
 106       </varlistentry>
 107
 108       <varlistentry>
 109         <term><option>--scope</option></term>
 110
 111         <listitem>
 112           <para>Create a transient <filename>.scope</filename> unit instead of the default transient
 113           <filename>.service</filename> unit (see above).
 114           </para>
 115         </listitem>
 116       </varlistentry>
 117
 118       <varlistentry>
 119         <term><option>--unit=</option></term>
 120
 121         <listitem><para>Use this unit name instead of an automatically
 122         generated one.</para></listitem>
 123       </varlistentry>
 124
 125       <varlistentry>
 126         <term><option>--property=</option></term>
 127         <term><option>-p</option></term>
 128
 129         <listitem><para>Sets a property on the scope or service unit that is created. This option takes an assignment
 130         in the same format as
 131         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
 132         <command>set-property</command> command.</para>
 133         </listitem>
 134       </varlistentry>
 135
 136       <varlistentry>
 137         <term><option>--description=</option></term>
 138
 139         <listitem><para>Provide a description for the service, scope, path, socket, or timer unit. If not specified,
 140         the command itself will be used as a description. See <varname>Description=</varname> in
 141         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 142         </para></listitem>
 143       </varlistentry>
 144
 145       <varlistentry>
 146         <term><option>--slice=</option></term>
 147
 148         <listitem><para>Make the new <filename>.service</filename> or <filename>.scope</filename> unit part of the
 149         specified slice, instead of <filename>system.slice</filename>.</para>
 150         </listitem>
 151       </varlistentry>
 152
 153       <varlistentry>
 154         <term><option>-r</option></term>
 155         <term><option>--remain-after-exit</option></term>
 156
 157         <listitem><para>After the service process has terminated, keep the service around until it is explicitly
 158         stopped. This is useful to collect runtime information about the service after it finished running. Also see
 159         <varname>RemainAfterExit=</varname> in
 160         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 161         </para>
 162         </listitem>
 163       </varlistentry>
 164
 165       <varlistentry>
 166         <term><option>--send-sighup</option></term>
 167
 168         <listitem><para>When terminating the scope or service unit, send a SIGHUP immediately after SIGTERM. This is
 169         useful to indicate to shells and shell-like processes that the connection has been severed. Also see
 170         <varname>SendSIGHUP=</varname> in
 171         <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 172         </para>
 173         </listitem>
 174       </varlistentry>
 175
 176       <varlistentry>
 177         <term><option>--service-type=</option></term>
 178
 179         <listitem><para>Sets the service type. Also see
 180         <varname>Type=</varname> in
 181         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>. This
 182         option has no effect in conjunction with
 183         <option>--scope</option>. Defaults to
 184         <constant>simple</constant>.</para>
 185         </listitem>
 186       </varlistentry>
 187
 188       <varlistentry>
 189         <term><option>--uid=</option></term>
 190         <term><option>--gid=</option></term>
 191
 192         <listitem><para>Runs the service process under the specified UNIX user and group. Also see
 193         <varname>User=</varname> and <varname>Group=</varname> in
 194         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 195         </listitem>
 196       </varlistentry>
 197
 198       <varlistentry>
 199         <term><option>--nice=</option></term>
 200
 201         <listitem><para>Runs the service process with the specified
 202         nice level. Also see <varname>Nice=</varname> in
 203         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 204         </listitem>
 205       </varlistentry>
 206
 207       <varlistentry>
 208         <term><option>--working-directory=</option></term>
 209
 210         <listitem><para>Runs the service process with the specified working directory. Also see
 211         <varname>WorkingDirectory=</varname> in
 212         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 213         </listitem>
 214       </varlistentry>
 215
 216       <varlistentry>
 217         <term><option>--same-dir</option></term>
 218         <term><option>-d</option></term>
 219
 220         <listitem><para>Similar to <option>--working-directory=</option> but uses the current working directory of the
 221         caller for the service to execute.</para></listitem>
 222       </varlistentry>
 223
 224       <varlistentry>
 225         <term><option>-E <replaceable>NAME</replaceable>=<replaceable>VALUE</replaceable></option></term>
 226         <term><option>--setenv=<replaceable>NAME</replaceable>=<replaceable>VALUE</replaceable></option></term>
 227
 228         <listitem><para>Runs the service process with the specified environment variable set.
 229         Also see <varname>Environment=</varname> in
 230         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 231         </listitem>
 232       </varlistentry>
 233
 234       <varlistentry>
 235         <term><option>--pty</option></term>
 236         <term><option>-t</option></term>
 237
 238         <listitem><para>When invoking the command, the transient service connects its standard input, output and error
 239         to the terminal <command>systemd-run</command> is invoked on, via a pseudo TTY device. This allows running
 240         programs that expect interactive user input/output as services, such as interactive command shells.</para>
 241
 242         <para>Note that
 243         <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
 244         <command>shell</command> command is usually a better alternative for requesting a new, interactive login
 245         session on the local host or a local container.</para>
 246
 247         <para>See below for details on how this switch combines with <option>--pipe</option>.</para></listitem>
 248       </varlistentry>
 249
 250       <varlistentry>
 251         <term><option>--pipe</option></term>
 252         <term><option>-P</option></term>
 253
 254         <listitem><para>If specified, standard input, output, and error of the transient service are inherited from the
 255         <command>systemd-run</command> command itself. This allows <command>systemd-run</command>
 256         to be used within shell pipelines.
 257         Note that this mode is not suitable for interactive command shells and similar, as the
 258         service process will not become a TTY controller when invoked on a terminal. Use <option>--pty</option> instead
 259         in that case.</para>
 260
 261         <para>When both <option>--pipe</option> and <option>--pty</option> are used in combination the more appropriate
 262         option is automatically determined and used. Specifically, when invoked with standard input, output and error
 263         connected to a TTY <option>--pty</option> is used, and otherwise <option>--pipe</option>.</para>
 264
 265         <para>When this option is used the original file descriptors <command>systemd-run</command> receives are passed
 266         to the service processes as-is. If the service runs with different privileges than
 267         <command>systemd-run</command>, this means the service might not be able to re-open the passed file
 268         descriptors, due to normal file descriptor access restrictions. If the invoked process is a shell script that
 269         uses the <command>echo "hello" > /dev/stderr</command> construct for writing messages to stderr, this might
 270         cause problems, as this only works if stderr can be re-opened. To mitigate this use the construct <command>echo
 271         "hello" >&amp;2</command> instead, which is mostly equivalent and avoids this pitfall.</para></listitem>
 272       </varlistentry>
 273
 274       <varlistentry>
 275         <term><option>--shell</option></term>
 276         <term><option>-S</option></term>
 277
 278         <listitem><para>A shortcut for <literal>--pty --same-dir --wait --collect --service-type=exec $SHELL</literal>,
 279         i.e. requests an interactive shell in the current working directory, running in service context, accessible
 280         with a single switch.</para></listitem>
 281       </varlistentry>
 282
 283       <varlistentry>
 284         <term><option>--quiet</option></term>
 285         <term><option>-q</option></term>
 286
 287         <listitem><para>Suppresses additional informational output
 288         while running. This is particularly useful in combination with
 289         <option>--pty</option> when it will suppress the initial
 290         message explaining how to terminate the TTY connection.</para></listitem>
 291       </varlistentry>
 292
 293       <varlistentry>
 294         <term><option>--on-active=</option></term>
 295         <term><option>--on-boot=</option></term>
 296         <term><option>--on-startup=</option></term>
 297         <term><option>--on-unit-active=</option></term>
 298         <term><option>--on-unit-inactive=</option></term>
 299
 300         <listitem><para>Defines a monotonic timer relative to different starting points for starting the specified
 301         command. See <varname>OnActiveSec=</varname>, <varname>OnBootSec=</varname>, <varname>OnStartupSec=</varname>,
 302         <varname>OnUnitActiveSec=</varname> and <varname>OnUnitInactiveSec=</varname> in
 303         <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
 304         details. These options are shortcuts for <command>--timer-property=</command> with the relevant properties.
 305         These options may not be combined with <option>--scope</option> or <option>--pty</option>.</para>
 306         </listitem>
 307       </varlistentry>
 308
 309       <varlistentry>
 310         <term><option>--on-calendar=</option></term>
 311
 312         <listitem><para>Defines a calendar timer for starting the specified command. See <varname>OnCalendar=</varname>
 313         in <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>. This
 314         option is a shortcut for <command>--timer-property=OnCalendar=</command>. This option may not be combined with
 315         <option>--scope</option> or <option>--pty</option>.</para>
 316         </listitem>
 317       </varlistentry>
 318
 319       <varlistentry>
 320         <term><option>--on-clock-change</option></term>
 321         <term><option>--on-timezone-change</option></term>
 322
 323         <listitem><para>Defines a trigger based on system clock jumps or timezone changes for starting the
 324         specified command. See <varname>OnClockChange=</varname> and <varname>OnTimezoneChange=</varname> in
 325         <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>. These
 326         options are shortcuts for <command>--timer-property=OnClockChange=yes</command> and
 327         <command>--timer-property=OnTimezoneChange=yes</command>. These options may not be combined with
 328         <option>--scope</option> or <option>--pty</option>.</para></listitem>
 329       </varlistentry>
 330
 331       <varlistentry>
 332         <term><option>--path-property=</option></term>
 333         <term><option>--socket-property=</option></term>
 334         <term><option>--timer-property=</option></term>
 335
 336         <listitem><para>Sets a property on the path, socket, or timer unit that is created. This option is similar to
 337         <option>--property=</option> but applies to the transient path, socket, or timer unit rather than the
 338         transient service unit created. This option takes an assignment in the same format as
 339         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
 340         <command>set-property</command> command. These options may not be combined with
 341         <option>--scope</option> or <option>--pty</option>.</para>
 342         </listitem>
 343       </varlistentry>
 344
 345       <varlistentry>
 346         <term><option>--no-block</option></term>
 347
 348         <listitem>
 349           <para>Do not synchronously wait for the unit start operation to finish. If this option is not specified, the
 350           start request for the transient unit will be verified, enqueued and <command>systemd-run</command> will wait
 351           until the unit's start-up is completed. By passing this argument, it is only verified and enqueued. This
 352           option may not be combined with <option>--wait</option>.</para>
 353         </listitem>
 354       </varlistentry>
 355
 356       <varlistentry>
 357         <term><option>--wait</option></term>
 358
 359         <listitem><para>Synchronously wait for the transient service to terminate. If this option is specified, the
 360         start request for the transient unit is verified, enqueued, and waited for. Subsequently the invoked unit is
 361         monitored, and it is waited until it is deactivated again (most likely because the specified command
 362         completed). On exit, terse information about the unit's runtime is shown, including total runtime (as well as
 363         CPU usage, if <option>--property=CPUAccounting=1</option> was set) and the exit code and status of the main
 364         process. This output may be suppressed with <option>--quiet</option>. This option may not be combined with
 365         <option>--no-block</option>, <option>--scope</option> or the various path, socket, or timer options.</para></listitem>
 366       </varlistentry>
 367
 368       <varlistentry>
 369         <term><option>-G</option></term>
 370         <term><option>--collect</option></term>
 371
 372         <listitem><para>Unload the transient unit after it completed, even if it failed. Normally, without this option,
 373         all units that ran and failed are kept in memory until the user explicitly resets their failure state with
 374         <command>systemctl reset-failed</command> or an equivalent command. On the other hand, units that ran
 375         successfully are unloaded immediately. If this option is turned on the "garbage collection" of units is more
 376         aggressive, and unloads units regardless if they exited successfully or failed. This option is a shortcut for
 377         <command>--property=CollectMode=inactive-or-failed</command>, see the explanation for
 378         <varname>CollectMode=</varname> in
 379         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for further
 380         information.</para></listitem>
 381       </varlistentry>
 382
 383       <xi:include href="user-system-options.xml" xpointer="user" />
 384       <xi:include href="user-system-options.xml" xpointer="system" />
 385       <xi:include href="user-system-options.xml" xpointer="host" />
 386       <xi:include href="user-system-options.xml" xpointer="machine" />
 387
 388       <xi:include href="standard-options.xml" xpointer="help" />
 389       <xi:include href="standard-options.xml" xpointer="version" />
 390     </variablelist>
 391
 392     <para>All command line arguments after the first non-option
 393     argument become part of the command line of the launched
 394     process. If a command is run as service unit, the first argument
 395     needs to be an absolute program path.</para>
 396   </refsect1>
 397
 398   <refsect1>
 399     <title>Exit status</title>
 400
 401     <para>On success, 0 is returned, a non-zero failure
 402     code otherwise.</para>
 403   </refsect1>
 404
 405   <refsect1>
 406     <title>Examples</title>
 407
 408     <example>
 409       <title>Logging environment variables provided by systemd to services</title>
 410
 411       <programlisting># systemd-run env
 412 Running as unit: run-19945.service
 413 # journalctl -u run-19945.service
 414 Sep 08 07:37:21 bupkis systemd[1]: Starting /usr/bin/env...
 415 Sep 08 07:37:21 bupkis systemd[1]: Started /usr/bin/env.
 416 Sep 08 07:37:21 bupkis env[19948]: PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin
 417 Sep 08 07:37:21 bupkis env[19948]: LANG=en_US.UTF-8
 418 Sep 08 07:37:21 bupkis env[19948]: BOOT_IMAGE=/vmlinuz-3.11.0-0.rc5.git6.2.fc20.x86_64</programlisting>
 419     </example>
 420
 421     <example>
 422       <title>Limiting resources available to a command</title>
 423
 424       <programlisting># systemd-run -p BlockIOWeight=10 updatedb</programlisting>
 425
 426       <para>This command invokes the
 427       <citerefentry project='man-pages'><refentrytitle>updatedb</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 428       tool, but lowers the block I/O weight for it to 10. See
 429       <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 430       for more information on the <varname>BlockIOWeight=</varname>
 431       property.</para>
 432     </example>
 433
 434     <example>
 435       <title>Running commands at a specified time</title>
 436
 437       <para>The following command will touch a file after 30 seconds.</para>
 438
 439       <programlisting># date; systemd-run --on-active=30 --timer-property=AccuracySec=100ms /bin/touch /tmp/foo
 440 Mon Dec  8 20:44:24 KST 2014
 441 Running as unit: run-71.timer
 442 Will run service as unit: run-71.service
 443 # journalctl -b -u run-71.timer
 444 -- Logs begin at Fri 2014-12-05 19:09:21 KST, end at Mon 2014-12-08 20:44:54 KST. --
 445 Dec 08 20:44:38 container systemd[1]: Starting /bin/touch /tmp/foo.
 446 Dec 08 20:44:38 container systemd[1]: Started /bin/touch /tmp/foo.
 447 # journalctl -b -u run-71.service
 448 -- Logs begin at Fri 2014-12-05 19:09:21 KST, end at Mon 2014-12-08 20:44:54 KST. --
 449 Dec 08 20:44:48 container systemd[1]: Starting /bin/touch /tmp/foo...
 450 Dec 08 20:44:48 container systemd[1]: Started /bin/touch /tmp/foo.</programlisting>
 451     </example>
 452
 453     <example>
 454       <title>Allowing access to the tty</title>
 455
 456       <para>The following command invokes <filename>/bin/bash</filename> as a service
 457       passing its standard input, output and error to the calling TTY.</para>
 458
 459       <programlisting># systemd-run -t --send-sighup /bin/bash</programlisting>
 460     </example>
 461
 462     <example>
 463       <title>Start <command>screen</command> as a user service</title>
 464
 465       <programlisting>$ systemd-run --scope --user screen
 466 Running scope as unit run-r14b0047ab6df45bfb45e7786cc839e76.scope.
 467
 468 $ screen -ls
 469 There is a screen on:
 470         492..laptop     (Detached)
 471 1 Socket in /var/run/screen/S-fatima.
 472 </programlisting>
 473
 474       <para>This starts the <command>screen</command> process as a child of the
 475       <command>systemd --user</command> process that was started by
 476       <filename>user@.service</filename>, in a scope unit. A
 477       <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 478       unit is used instead of a
 479       <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 480       unit, because <command>screen</command> will exit when detaching from the terminal,
 481       and a service unit would be terminated. Running <command>screen</command>
 482       as a user unit has the advantage that it is not part of the session scope.
 483       If <varname>KillUserProcesses=yes</varname> is configured in
 484       <citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 485       the default, the session scope will be terminated when the user logs
 486       out of that session.</para>
 487
 488       <para>The <filename>user@.service</filename> is started automatically
 489       when the user first logs in, and stays around as long as at least one
 490       login session is open. After the user logs out of the last session,
 491       <filename>user@.service</filename> and all services underneath it
 492       are terminated. This behavior is the default, when "lingering" is
 493       not enabled for that user. Enabling lingering means that
 494       <filename>user@.service</filename> is started automatically during
 495       boot, even if the user is not logged in, and that the service is
 496       not terminated when the user logs out.</para>
 497
 498       <para>Enabling lingering allows the user to run processes without being logged in,
 499       for example to allow <command>screen</command> to persist after the user logs out,
 500       even if the session scope is terminated. In the default configuration, users can
 501       enable lingering for themselves:</para>
 502
 503       <programlisting>$ loginctl enable-linger</programlisting>
 504     </example>
 505   </refsect1>
 506
 507   <refsect1>
 508     <title>See Also</title>
 509     <para>
 510       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 511       <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 512       <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 513       <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 514       <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 515       <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 516       <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 517       <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 518       <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 519       <citerefentry><refentrytitle>systemd-mount</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 520       <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 521     </para>
 522   </refsect1>
 523
 524 </refentry>