<option>false</option> and <option>off</option> are
equivalent.</para>
- <para>Time span values encoded in unit files can be written in various formats. A stand-alone number specifies a
- time in seconds. If suffixed with a time unit, the unit is honored. A concatenation of multiple values with units
- is supported, in which case the values are added up. Example: <literal>50</literal> refers to 50 seconds;
- <literal>2min 200ms</literal> refers to 2 minutes and 200 milliseconds, i.e. 120200 ms. The following time units
- are understood: <literal>s</literal>, <literal>min</literal>, <literal>h</literal>, <literal>d</literal>,
+ <para>Time span values encoded in unit files can be written in various formats. A stand-alone
+ number specifies a time in seconds. If suffixed with a time unit, the unit is honored. A
+ concatenation of multiple values with units is supported, in which case the values are added
+ up. Example: <literal>50</literal> refers to 50 seconds; <literal>2min 200ms</literal> refers to
+ 2 minutes and 200 milliseconds, i.e. 120200 ms. The following time units are understood:
+ <literal>s</literal>, <literal>min</literal>, <literal>h</literal>, <literal>d</literal>,
<literal>w</literal>, <literal>ms</literal>, <literal>us</literal>. For details see
<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
- <para>Empty lines and lines starting with <literal>#</literal> or <literal>;</literal> are ignored. This may be
- used for commenting. Lines ending in a backslash are concatenated with the following line while reading and the
- backslash is replaced by a space character. This may be used to wrap long lines.</para>
-
- <para>Units can be aliased (have an alternative name), by creating a symlink from the new name to the existing name
- in one of the unit search paths. For example, <filename>systemd-networkd.service</filename> has the alias
- <filename>dbus-org.freedesktop.network1.service</filename>, created during installation as the symlink
- <filename>/usr/lib/systemd/system/dbus-org.freedesktop.network1.service</filename>. In addition, unit files may
- specify aliases through the <varname>Alias=</varname> directive in the [Install] section; those aliases are only
- effective when the unit is enabled. When the unit is enabled, symlinks will be created for those names, and removed
- when the unit is disabled. For example, <filename>reboot.target</filename> specifies
- <varname>Alias=ctrl-alt-del.target</varname>, so when enabled it will be invoked whenever CTRL+ALT+DEL is
- pressed. Alias names may be used in commands like <command>enable</command>, <command>disable</command>,
- <command>start</command>, <command>stop</command>, <command>status</command>, …, and in unit dependency directives
- <varname>Wants=</varname>, <varname>Requires=</varname>, <varname>Before=</varname>, <varname>After=</varname>, …,
- with the limitation that aliases specified through <varname>Alias=</varname> are only effective when the unit is
- enabled. Aliases cannot be used with the <command>preset</command> command.</para>
-
- <para>Along with a unit file <filename>foo.service</filename>, the
- directory <filename>foo.service.wants/</filename> may exist. All
- unit files symlinked from such a directory are implicitly added as
- dependencies of type <varname>Wants=</varname> to the unit. This
- is useful to hook units into the start-up of other units, without
- having to modify their unit files. For details about the semantics
- of <varname>Wants=</varname>, see below. The preferred way to
- create symlinks in the <filename>.wants/</filename> directory of a
- unit file is with the <command>enable</command> command of the
+ <para>Empty lines and lines starting with <literal>#</literal> or <literal>;</literal> are
+ ignored. This may be used for commenting. Lines ending in a backslash are concatenated with the
+ following line while reading and the backslash is replaced by a space character. This may be
+ used to wrap long lines.</para>
+
+ <para>Units can be aliased (have an alternative name), by creating a symlink from the new name
+ to the existing name in one of the unit search paths. For example,
+ <filename>systemd-networkd.service</filename> has the alias
+ <filename>dbus-org.freedesktop.network1.service</filename>, created during installation as the
+ symlink <filename>/usr/lib/systemd/system/dbus-org.freedesktop.network1.service</filename>. In
+ addition, unit files may specify aliases through the <varname>Alias=</varname> directive in the
+ [Install] section; those aliases are only effective when the unit is enabled. When the unit is
+ enabled, symlinks will be created for those names, and removed when the unit is disabled. For
+ example, <filename>reboot.target</filename> specifies
+ <varname>Alias=ctrl-alt-del.target</varname>, so when enabled it will be invoked whenever
+ CTRL+ALT+DEL is pressed. Alias names may be used in commands like <command>enable</command>,
+ <command>disable</command>, <command>start</command>, <command>stop</command>,
+ <command>status</command>, …, and in unit dependency directives <varname>Wants=</varname>,
+ <varname>Requires=</varname>, <varname>Before=</varname>, <varname>After=</varname>, …, with the
+ limitation that aliases specified through <varname>Alias=</varname> are only effective when the
+ unit is enabled. Aliases cannot be used with the <command>preset</command> command.</para>
+
+ <para>Along with a unit file <filename>foo.service</filename>, the directory
+ <filename>foo.service.wants/</filename> may exist. All unit files symlinked from such a
+ directory are implicitly added as dependencies of type <varname>Wants=</varname> to the unit.
+ This is useful to hook units into the start-up of other units, without having to modify their
+ unit files. For details about the semantics of <varname>Wants=</varname>, see below. The
+ preferred way to create symlinks in the <filename>.wants/</filename> directory of a unit file is
+ with the <command>enable</command> command of the
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- tool which reads information from the [Install] section of unit
- files (see below). A similar functionality exists for
- <varname>Requires=</varname> type dependencies as well, the
- directory suffix is <filename>.requires/</filename> in this
- case.</para>
+ tool which reads information from the [Install] section of unit files (see below). A similar
+ functionality exists for <varname>Requires=</varname> type dependencies as well, the directory
+ suffix is <filename>.requires/</filename> in this case.</para>
<para>Along with a unit file <filename>foo.service</filename>, a "drop-in" directory
- <filename>foo.service.d/</filename> may exist. All files with the suffix <literal>.conf</literal> from this
- directory will be parsed after the file itself is parsed. This is useful to alter or add configuration settings for
- a unit, without having to modify unit files. Each drop-in file must have appropriate section headers. Note that for
- instantiated units, this logic will first look for the instance <literal>.d/</literal> subdirectory and read its
- <literal>.conf</literal> files, followed by the template <literal>.d/</literal> subdirectory and the
- <literal>.conf</literal> files there. Also note that settings from the <literal>[Install]</literal> section are not
- honoured in drop-in unit files, and have no effect.</para>
-
- <para>In addition to <filename>/etc/systemd/system</filename>,
- the drop-in <literal>.conf</literal> files for system services
- can be placed in <filename>/usr/lib/systemd/system</filename> or
- <filename>/run/systemd/system</filename> directories. Drop-in
- files in <filename>/etc</filename> take precedence over those in
- <filename>/run</filename> which in turn take precedence over
- those in <filename>/usr/lib</filename>. Drop-in files under any of
- these directories take precedence over unit files wherever located.
- (Of course, since <filename>/run</filename> is temporary and
- <filename>/usr/lib</filename> is for vendors, it is unlikely
- drop-ins should be used in either of those places.)</para>
- <!-- Note that we do not document .include here, as we
- consider it mostly obsolete, and want people to
- use .d/ drop-ins instead. -->
+ <filename>foo.service.d/</filename> may exist. All files with the suffix
+ <literal>.conf</literal> from this directory will be parsed after the file itself is
+ parsed. This is useful to alter or add configuration settings for a unit, without having to
+ modify unit files. Each drop-in file must have appropriate section headers. Note that for
+ instantiated units, this logic will first look for the instance <literal>.d/</literal>
+ subdirectory and read its <literal>.conf</literal> files, followed by the template
+ <literal>.d/</literal> subdirectory and the <literal>.conf</literal> files there. Also note that
+ settings from the <literal>[Install]</literal> section are not honoured in drop-in unit files,
+ and have no effect.</para>
+
+ <para>In addition to <filename>/etc/systemd/system</filename>, the drop-in <literal>.d</literal>
+ directories for system services can be placed in <filename>/usr/lib/systemd/system</filename> or
+ <filename>/run/systemd/system</filename> directories. Drop-in files in <filename>/etc</filename>
+ take precedence over those in <filename>/run</filename> which in turn take precedence over those
+ in <filename>/usr/lib</filename>. Drop-in files under any of these directories take precedence
+ over unit files wherever located. (Of course, since <filename>/run</filename> is temporary and
+ <filename>/usr/lib</filename> is for vendors, it is unlikely drop-ins should be used in either
+ of those places.)</para>
+
+ <!-- Note that we do not document .include here, as we consider it mostly obsolete, and want
+ people to use .d/ drop-ins instead. -->
<para>Some unit names reflect paths existing in the file system
namespace. Example: a device unit
projects / thirdparty / systemd.git / blobdiff