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+<?xml version='1.0'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+ "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
+
+<refentry id="systemd-run"
+ xmlns:xi="http://www.w3.org/2001/XInclude">
+
+ <refentryinfo>
+ <title>systemd-run</title>
+ <productname>systemd</productname>
+ </refentryinfo>
+
+ <refmeta>
+ <refentrytitle>systemd-run</refentrytitle>
+ <manvolnum>1</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>systemd-run</refname>
+ <refpurpose>Run programs in transient scope units, service units, or path-, socket-, or timer-triggered service units</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <cmdsynopsis>
+ <command>systemd-run</command>
+ <arg choice="opt" rep="repeat">OPTIONS</arg>
+ <arg choice="plain"><replaceable>COMMAND</replaceable>
+ <arg choice="opt" rep="repeat">ARGS</arg>
+ </arg>
+ </cmdsynopsis>
+ <cmdsynopsis>
+ <command>systemd-run</command>
+ <arg choice="opt" rep="repeat">OPTIONS</arg>
+ <arg choice="opt" rep="repeat">PATH OPTIONS</arg>
+ <arg choice="req"><replaceable>COMMAND</replaceable></arg>
+ <arg choice="opt" rep="repeat">ARGS</arg>
+ </cmdsynopsis>
+ <cmdsynopsis>
+ <command>systemd-run</command>
+ <arg choice="opt" rep="repeat">OPTIONS</arg>
+ <arg choice="opt" rep="repeat">SOCKET OPTIONS</arg>
+ <arg choice="req"><replaceable>COMMAND</replaceable></arg>
+ <arg choice="opt" rep="repeat">ARGS</arg>
+ </cmdsynopsis>
+ <cmdsynopsis>
+ <command>systemd-run</command>
+ <arg choice="opt" rep="repeat">OPTIONS</arg>
+ <arg choice="opt" rep="repeat">TIMER OPTIONS</arg>
+ <arg choice="req"><replaceable>COMMAND</replaceable></arg>
+ <arg choice="opt" rep="repeat">ARGS</arg>
+ </cmdsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><command>systemd-run</command> may be used to create and start a transient <filename>.service</filename> or
+ <filename>.scope</filename> unit and run the specified <replaceable>COMMAND</replaceable> in it. It may also be
+ used to create and start a transient <filename>.path</filename>, <filename>.socket</filename>, or
+ <filename>.timer</filename> unit, that activates a <filename>.service</filename> unit when elapsing.</para>
+
+ <para>If a command is run as transient service unit, it will be started and managed by the service manager like any
+ other service, and thus shows up in the output of <command>systemctl list-units</command> like any other unit. It
+ will run in a clean and detached execution environment, with the service manager as its parent process. In this
+ mode, <command>systemd-run</command> will start the service asynchronously in the background and return after the
+ command has begun execution (unless <option>--no-block</option> or <option>--wait</option> are specified, see
+ below).</para>
+
+ <para>If a command is run as transient scope unit, it will be executed by <command>systemd-run</command>
+ itself as parent process and will thus inherit the execution environment of the caller. However, the
+ processes of the command are managed by the service manager similarly to normal services, and will show
+ up in the output of <command>systemctl list-units</command>. Execution in this case is synchronous, and
+ will return only when the command finishes. This mode is enabled via the <option>--scope</option> switch
+ (see below).</para>
+
+ <para>If a command is run with path, socket, or timer options such as <option>--on-calendar=</option> (see below),
+ a transient path, socket, or timer unit is created alongside the service unit for the specified command. Only the
+ transient path, socket, or timer unit is started immediately, the transient service unit will be triggered by the
+ path, socket, or timer unit. If the <option>--unit=</option> option is specified, the
+ <replaceable>COMMAND</replaceable> may be omitted. In this case, <command>systemd-run</command> creates only a
+ <filename>.path</filename>, <filename>.socket</filename>, or <filename>.timer</filename> unit that triggers the
+ specified unit.</para>
+
+ <para>By default, services created with <command>systemd-run</command> default to the
+ <option>simple</option> type, see the description of <varname>Type=</varname> in
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ details. Note that when this type is used, the service manager (and thus the
+ <command>systemd-run</command> command) considers service start-up successful as soon as the
+ <function>fork()</function> for the main service process succeeded, i.e. before the
+ <function>execve()</function> is invoked, and thus even if the specified command cannot be started.
+ Consider using the <option>exec</option> service type (i.e. <option>--property=Type=exec</option>) to
+ ensure that <command>systemd-run</command> returns successfully only if the specified command line has
+ been successfully started.</para>
+
+ <para>After <command>systemd-run</command> passes the command to the service manager, the manager
+ performs variable expansion. This means that dollar characters (<literal>$</literal>) which should not be
+ expanded need to be escaped as <literal>$$</literal>. Expansion can also be disabled using
+ <varname>--expand-environment=no</varname>.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Options</title>
+
+ <para>The following options are understood:</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><option>--no-ask-password</option></term>
+
+ <listitem><para>Do not query the user for authentication for
+ privileged operations.</para>
+
+ <xi:include href="version-info.xml" xpointer="v226"/></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--scope</option></term>
+
+ <listitem>
+ <para>Create a transient <filename>.scope</filename> unit instead of the default transient
+ <filename>.service</filename> unit (see above).
+ </para>
+
+ <xi:include href="version-info.xml" xpointer="v206"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--unit=</option></term>
+ <term><option>-u</option></term>
+
+ <listitem><para>Use this unit name instead of an automatically
+ generated one.</para>
+
+ <xi:include href="version-info.xml" xpointer="v206"/></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--property=</option></term>
+ <term><option>-p</option></term>
+
+ <listitem><para>Sets a property on the scope or service unit that is created. This option takes an assignment
+ in the same format as
+ <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
+ <command>set-property</command> command.</para>
+
+ <xi:include href="version-info.xml" xpointer="v211"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--description=</option></term>
+
+ <listitem><para>Provide a description for the service, scope, path, socket, or timer unit. If not specified,
+ the command itself will be used as a description. See <varname>Description=</varname> in
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ </para>
+
+ <xi:include href="version-info.xml" xpointer="v206"/></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--slice=</option></term>
+
+ <listitem><para>Make the new <filename>.service</filename> or <filename>.scope</filename> unit part
+ of the specified slice, instead of <filename>system.slice</filename> (when running in
+ <option>--system</option> mode) or the root slice (when running in <option>--user</option>
+ mode).</para>
+
+ <xi:include href="version-info.xml" xpointer="v206"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--slice-inherit</option></term>
+
+ <listitem><para>Make the new <filename>.service</filename> or <filename>.scope</filename> unit part
+ of the inherited slice. This option can be combined with <option>--slice=</option>.</para>
+
+ <para>An inherited slice is located within <command>systemd-run</command> slice. Example: if
+ <command>systemd-run</command> slice is <filename>foo.slice</filename>, and the
+ <option>--slice=</option> argument is <filename>bar</filename>, the unit will be placed under the
+ <filename>foo-bar.slice</filename>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v246"/>
+
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--expand-environment=<replaceable>BOOL</replaceable></option></term>
+
+ <listitem><para>Expand environment variables in command arguments. If enabled, environment variables
+ specified as <literal>${<replaceable>VARIABLE</replaceable>}</literal> will be expanded in the same
+ way as in commands specified via <varname>ExecStart=</varname> in units. With
+ <varname>--scope</varname>, this expansion is performed by <command>systemd-run</command> itself, and
+ in other cases by the service manager that spawns the command. Note that this is similar to, but not
+ the same as variable expansion in
+ <citerefentry project='man-pages'><refentrytitle>bash</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ and other shells.</para>
+
+ <para>The default is to enable this option in all cases, except for <varname>--scope</varname> where
+ it is disabled by default, for backward compatibility reasons. Note that this will be changed in a
+ future release, where it will be switched to enabled by default as well.</para>
+
+ <para>See
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for a description of variable expansion. Disabling variable expansion is useful if the specified
+ command includes or may include a <literal>$</literal> sign.</para>
+
+ <xi:include href="version-info.xml" xpointer="v254"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>-r</option></term>
+ <term><option>--remain-after-exit</option></term>
+
+ <listitem><para>After the service process has terminated, keep the service around until it is explicitly
+ stopped. This is useful to collect runtime information about the service after it finished running. Also see
+ <varname>RemainAfterExit=</varname> in
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ </para>
+
+ <xi:include href="version-info.xml" xpointer="v207"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--send-sighup</option></term>
+
+ <listitem><para>When terminating the scope or service unit, send a SIGHUP immediately after SIGTERM. This is
+ useful to indicate to shells and shell-like processes that the connection has been severed. Also see
+ <varname>SendSIGHUP=</varname> in
+ <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ </para>
+
+ <xi:include href="version-info.xml" xpointer="v207"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--service-type=</option></term>
+
+ <listitem><para>Sets the service type. Also see
+ <varname>Type=</varname> in
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>. This
+ option has no effect in conjunction with
+ <option>--scope</option>. Defaults to
+ <constant>simple</constant>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v211"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--uid=</option></term>
+ <term><option>--gid=</option></term>
+
+ <listitem><para>Runs the service process under the specified UNIX user and group. Also see
+ <varname>User=</varname> and <varname>Group=</varname> in
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v211"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--nice=</option></term>
+
+ <listitem><para>Runs the service process with the specified
+ nice level. Also see <varname>Nice=</varname> in
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v211"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--working-directory=</option></term>
+
+ <listitem><para>Runs the service process with the specified working directory. Also see
+ <varname>WorkingDirectory=</varname> in
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v240"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--same-dir</option></term>
+ <term><option>-d</option></term>
+
+ <listitem><para>Similar to <option>--working-directory=</option>, but uses the current working
+ directory of the caller for the service to execute.</para>
+
+ <xi:include href="version-info.xml" xpointer="v240"/></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>-E <replaceable>NAME</replaceable>[=<replaceable>VALUE</replaceable>]</option></term>
+ <term><option>--setenv=<replaceable>NAME</replaceable>[=<replaceable>VALUE</replaceable>]</option></term>
+
+ <listitem><para>Runs the service process with the specified environment variable set. This parameter
+ may be used more than once to set multiple variables. When <literal>=</literal> and
+ <replaceable>VALUE</replaceable> are omitted, the value of the variable with the same name in the
+ program environment will be used.</para>
+
+ <para>Also see <varname>Environment=</varname> in
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v211"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--pty</option></term>
+ <term><option>-t</option></term>
+
+ <listitem><para>When invoking the command, the transient service connects its standard input, output and error
+ to the terminal <command>systemd-run</command> is invoked on, via a pseudo TTY device. This allows running
+ programs that expect interactive user input/output as services, such as interactive command shells.</para>
+
+ <para>Note that
+ <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
+ <command>shell</command> command is usually a better alternative for requesting a new, interactive login
+ session on the local host or a local container.</para>
+
+ <para>See below for details on how this switch combines with <option>--pipe</option>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v219"/></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--pipe</option></term>
+ <term><option>-P</option></term>
+
+ <listitem><para>If specified, standard input, output, and error of the transient service are inherited from the
+ <command>systemd-run</command> command itself. This allows <command>systemd-run</command>
+ to be used within shell pipelines.
+ Note that this mode is not suitable for interactive command shells and similar, as the
+ service process will not become a TTY controller when invoked on a terminal. Use <option>--pty</option> instead
+ in that case.</para>
+
+ <para>When both <option>--pipe</option> and <option>--pty</option> are used in combination the more appropriate
+ option is automatically determined and used. Specifically, when invoked with standard input, output and error
+ connected to a TTY <option>--pty</option> is used, and otherwise <option>--pipe</option>.</para>
+
+ <para>When this option is used the original file descriptors <command>systemd-run</command> receives are passed
+ to the service processes as-is. If the service runs with different privileges than
+ <command>systemd-run</command>, this means the service might not be able to re-open the passed file
+ descriptors, due to normal file descriptor access restrictions. If the invoked process is a shell script that
+ uses the <command>echo "hello" >/dev/stderr</command> construct for writing messages to stderr, this might
+ cause problems, as this only works if stderr can be re-opened. To mitigate this use the construct <command>echo
+ "hello" >&amp;2</command> instead, which is mostly equivalent and avoids this pitfall.</para>
+
+ <xi:include href="version-info.xml" xpointer="v235"/></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--shell</option></term>
+ <term><option>-S</option></term>
+
+ <listitem><para>A shortcut for <literal>--pty --same-dir --wait --collect --service-type=exec $SHELL</literal>,
+ i.e. requests an interactive shell in the current working directory, running in service context, accessible
+ with a single switch.</para>
+
+ <xi:include href="version-info.xml" xpointer="v240"/></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--quiet</option></term>
+ <term><option>-q</option></term>
+
+ <listitem><para>Suppresses additional informational output
+ while running. This is particularly useful in combination with
+ <option>--pty</option> when it will suppress the initial
+ message explaining how to terminate the TTY connection.</para>
+
+ <xi:include href="version-info.xml" xpointer="v219"/></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--on-active=</option></term>
+ <term><option>--on-boot=</option></term>
+ <term><option>--on-startup=</option></term>
+ <term><option>--on-unit-active=</option></term>
+ <term><option>--on-unit-inactive=</option></term>
+
+ <listitem><para>Defines a monotonic timer relative to different starting points for starting the specified
+ command. See <varname>OnActiveSec=</varname>, <varname>OnBootSec=</varname>, <varname>OnStartupSec=</varname>,
+ <varname>OnUnitActiveSec=</varname> and <varname>OnUnitInactiveSec=</varname> in
+ <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ details. These options are shortcuts for <command>--timer-property=</command> with the relevant properties.
+ These options may not be combined with <option>--scope</option> or <option>--pty</option>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v218"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--on-calendar=</option></term>
+
+ <listitem><para>Defines a calendar timer for starting the specified command. See <varname>OnCalendar=</varname>
+ in <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>. This
+ option is a shortcut for <command>--timer-property=OnCalendar=</command>. This option may not be combined with
+ <option>--scope</option> or <option>--pty</option>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v218"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--on-clock-change</option></term>
+ <term><option>--on-timezone-change</option></term>
+
+ <listitem><para>Defines a trigger based on system clock jumps or timezone changes for starting the
+ specified command. See <varname>OnClockChange=</varname> and <varname>OnTimezoneChange=</varname> in
+ <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>. These
+ options are shortcuts for <command>--timer-property=OnClockChange=yes</command> and
+ <command>--timer-property=OnTimezoneChange=yes</command>. These options may not be combined with
+ <option>--scope</option> or <option>--pty</option>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v242"/></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--path-property=</option></term>
+ <term><option>--socket-property=</option></term>
+ <term><option>--timer-property=</option></term>
+
+ <listitem><para>Sets a property on the path, socket, or timer unit that is created. This option is
+ similar to <option>--property=</option>, but applies to the transient path, socket, or timer unit
+ rather than the transient service unit created. This option takes an assignment in the same format as
+ <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
+ <command>set-property</command> command. These options may not be combined with
+ <option>--scope</option> or <option>--pty</option>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v218"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--no-block</option></term>
+
+ <listitem>
+ <para>Do not synchronously wait for the unit start operation to finish. If this option is not specified, the
+ start request for the transient unit will be verified, enqueued and <command>systemd-run</command> will wait
+ until the unit's start-up is completed. By passing this argument, it is only verified and enqueued. This
+ option may not be combined with <option>--wait</option>.</para>
+
+ <xi:include href="version-info.xml" xpointer="v220"/>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--wait</option></term>
+
+ <listitem><para>Synchronously wait for the transient service to terminate. If this option is specified, the
+ start request for the transient unit is verified, enqueued, and waited for. Subsequently the invoked unit is
+ monitored, and it is waited until it is deactivated again (most likely because the specified command
+ completed). On exit, terse information about the unit's runtime is shown, including total runtime (as well as
+ CPU usage, if <option>--property=CPUAccounting=1</option> was set) and the exit code and status of the main
+ process. This output may be suppressed with <option>--quiet</option>. This option may not be combined with
+ <option>--no-block</option>, <option>--scope</option> or the various path, socket, or timer options.</para>
+
+ <xi:include href="version-info.xml" xpointer="v232"/></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>-G</option></term>
+ <term><option>--collect</option></term>
+
+ <listitem><para>Unload the transient unit after it completed, even if it failed. Normally, without this option,
+ all units that ran and failed are kept in memory until the user explicitly resets their failure state with
+ <command>systemctl reset-failed</command> or an equivalent command. On the other hand, units that ran
+ successfully are unloaded immediately. If this option is turned on the "garbage collection" of units is more
+ aggressive, and unloads units regardless if they exited successfully or failed. This option is a shortcut for
+ <command>--property=CollectMode=inactive-or-failed</command>, see the explanation for
+ <varname>CollectMode=</varname> in
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for further
+ information.</para>
+
+ <xi:include href="version-info.xml" xpointer="v236"/></listitem>
+ </varlistentry>
+
+ <xi:include href="user-system-options.xml" xpointer="user" />
+ <xi:include href="user-system-options.xml" xpointer="system" />
+ <xi:include href="user-system-options.xml" xpointer="host" />
+ <xi:include href="user-system-options.xml" xpointer="machine" />
+
+ <xi:include href="standard-options.xml" xpointer="help" />
+ <xi:include href="standard-options.xml" xpointer="version" />
+ </variablelist>
+
+ <para>All command line arguments after the first non-option argument become part of the command line of
+ the launched process.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Exit status</title>
+
+ <para>On success, 0 is returned. If <command>systemd-run</command> failed to start the service, a
+ non-zero return value will be returned. If <command>systemd-run</command> waits for the service to
+ terminate, the return value will be propagated from the service. 0 will be returned on success, including
+ all the cases where systemd considers a service to have exited cleanly, see the discussion of
+ <varname>SuccessExitStatus=</varname> in
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <example>
+ <title>Logging environment variables provided by systemd to services</title>
+
+ <programlisting># systemd-run env
+Running as unit: run-19945.service
+# journalctl -u run-19945.service
+Sep 08 07:37:21 bupkis systemd[1]: Starting /usr/bin/env...
+Sep 08 07:37:21 bupkis systemd[1]: Started /usr/bin/env.
+Sep 08 07:37:21 bupkis env[19948]: PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin
+Sep 08 07:37:21 bupkis env[19948]: LANG=en_US.UTF-8
+Sep 08 07:37:21 bupkis env[19948]: BOOT_IMAGE=/vmlinuz-3.11.0-0.rc5.git6.2.fc20.x86_64</programlisting>
+ </example>
+
+ <example>
+ <title>Limiting resources available to a command</title>
+
+ <programlisting># systemd-run -p IOWeight=10 updatedb</programlisting>
+
+ <para>This command invokes the <citerefentry
+ project='man-pages'><refentrytitle>updatedb</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ tool, but lowers the block I/O weight for it to 10. See
+ <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for more information on the <varname>IOWeight=</varname> property.</para>
+ </example>
+
+ <example>
+ <title>Running commands at a specified time</title>
+
+ <para>The following command will touch a file after 30 seconds.</para>
+
+ <programlisting># date; systemd-run --on-active=30 --timer-property=AccuracySec=100ms /bin/touch /tmp/foo
+Mon Dec 8 20:44:24 KST 2014
+Running as unit: run-71.timer
+Will run service as unit: run-71.service
+# journalctl -b -u run-71.timer
+-- Journal begins at Fri 2014-12-05 19:09:21 KST, ends at Mon 2014-12-08 20:44:54 KST. --
+Dec 08 20:44:38 container systemd[1]: Starting /bin/touch /tmp/foo.
+Dec 08 20:44:38 container systemd[1]: Started /bin/touch /tmp/foo.
+# journalctl -b -u run-71.service
+-- Journal begins at Fri 2014-12-05 19:09:21 KST, ends at Mon 2014-12-08 20:44:54 KST. --
+Dec 08 20:44:48 container systemd[1]: Starting /bin/touch /tmp/foo...
+Dec 08 20:44:48 container systemd[1]: Started /bin/touch /tmp/foo.</programlisting>
+ </example>
+
+ <example>
+ <title>Allowing access to the tty</title>
+
+ <para>The following command invokes
+ <citerefentry project='man-pages'><refentrytitle>bash</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ as a service passing its standard input, output and error to the calling TTY.</para>
+
+ <programlisting># systemd-run -t --send-sighup bash</programlisting>
+ </example>
+
+ <example>
+ <title>Start <command>screen</command> as a user service</title>
+
+ <programlisting>$ systemd-run --scope --user screen
+Running scope as unit run-r14b0047ab6df45bfb45e7786cc839e76.scope.
+
+$ screen -ls
+There is a screen on:
+ 492..laptop (Detached)
+1 Socket in /var/run/screen/S-fatima.
+</programlisting>
+
+ <para>This starts the <command>screen</command> process as a child of the
+ <command>systemd --user</command> process that was started by
+ <filename>user@.service</filename>, in a scope unit. A
+ <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ unit is used instead of a
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ unit, because <command>screen</command> will exit when detaching from the terminal,
+ and a service unit would be terminated. Running <command>screen</command>
+ as a user unit has the advantage that it is not part of the session scope.
+ If <varname>KillUserProcesses=yes</varname> is configured in
+ <citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ the default, the session scope will be terminated when the user logs
+ out of that session.</para>
+
+ <para>The <filename>user@.service</filename> is started automatically
+ when the user first logs in, and stays around as long as at least one
+ login session is open. After the user logs out of the last session,
+ <filename>user@.service</filename> and all services underneath it
+ are terminated. This behavior is the default, when "lingering" is
+ not enabled for that user. Enabling lingering means that
+ <filename>user@.service</filename> is started automatically during
+ boot, even if the user is not logged in, and that the service is
+ not terminated when the user logs out.</para>
+
+ <para>Enabling lingering allows the user to run processes without being logged in,
+ for example to allow <command>screen</command> to persist after the user logs out,
+ even if the session scope is terminated. In the default configuration, users can
+ enable lingering for themselves:</para>
+
+ <programlisting>$ loginctl enable-linger</programlisting>
+ </example>
+
+ <example>
+ <title>Variable expansion by the manager</title>
+
+ <programlisting>$ systemd-run -t echo "&lt;${INVOCATION_ID}>" '&lt;${INVOCATION_ID}>'
+ &lt;> &lt;5d0149bfa2c34b79bccb13074001eb20>
+ </programlisting>
+
+ <para>The first argument is expanded by the shell (double quotes), but the second one is not expanded
+ by the shell (single quotes).
+ <citerefentry project='man-pages'><refentrytitle>echo</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ is called with [<literal>/usr/bin/echo</literal>,
+ <literal>&lt;></literal>, <literal>&lt;${INVOCATION_ID}></literal>] as the argument array, and then
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ generates <varname>${INVOCATION_ID}</varname> and substitutes it in the command-line. This substitution
+ could not be done on the client side, because the target ID that will be set for the service isn't
+ known before the call is made.</para>
+ </example>
+
+ <example>
+ <title>Variable expansion and output redirection using a shell</title>
+
+ <para>Variable expansion by
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ can be disabled with <varname>--expand-environment=no</varname>.</para>
+
+ <para>Disabling variable expansion can be useful if the command to execute contains dollar characters
+ and escaping them would be inconvenient. For example, when a shell is used:</para>
+
+ <programlisting>$ systemd-run --expand-environment=no -t bash \
+ -c 'echo $SHELL $$ >/dev/stdout'
+/bin/bash 12345
+ </programlisting>
+
+ <para>The last argument is passed verbatim to the
+ <citerefentry project='man-pages'><refentrytitle>bash</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ shell which is started by the service unit. The shell expands <literal>$SHELL</literal> to the path of
+ the shell, and <literal>$$</literal> to its process number, and then those strings are passed to the
+ <command>echo</command> built-in and printed to standard output (which in this case is connected to the
+ calling terminal).</para>
+ </example>
+
+ <example>
+ <title>Return value</title>
+
+ <programlisting>$ systemd-run --user --wait true
+$ systemd-run --user --wait -p SuccessExitStatus=11 bash -c 'exit 11'
+$ systemd-run --user --wait -p SuccessExitStatus=SIGUSR1 --expand-environment=no \
+ bash -c 'kill -SIGUSR1 $$'</programlisting>
+
+ <para>Those three invocations will succeed, i.e. terminate with an exit code of 0.</para>
+ </example>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+ <para>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-mount</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>