X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=man%2Fsystemd.unit.xml;h=35dd4c78c4cc00de502100bbab1847c863855a66;hb=f9f4dd51bdb016bab84f7fb3cf47a2ad102b4c76;hp=e0aadf4cd30313236727136c09b7446a1ea70219;hpb=c53158818d8cdaf46b3f1b5299b9bda118a1043f;p=elogind.git

diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml
index e0aadf4cd..35dd4c78c 100644
--- a/man/systemd.unit.xml
+++ b/man/systemd.unit.xml
@@ -1,6 +1,9 @@
 <?xml version='1.0'?> <!--*-nxml-*-->
 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
-        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
+<!ENTITY % entities SYSTEM "custom-entities.ent" >
+%entities;
+]>
 
 <!--
   This file is part of systemd.
@@ -48,16 +51,31 @@
         </refnamediv>
 
         <refsynopsisdiv>
-                <para><filename>systemd.service</filename>,
-                <filename>systemd.socket</filename>,
-                <filename>systemd.device</filename>,
-                <filename>systemd.mount</filename>,
-                <filename>systemd.automount</filename>,
-                <filename>systemd.swap</filename>,
-                <filename>systemd.target</filename>,
-                <filename>systemd.path</filename>,
-                <filename>systemd.timer</filename>,
-                <filename>systemd.snapshot</filename></para>
+                <para><filename><replaceable>service</replaceable>.service</filename>,
+                <filename><replaceable>socket</replaceable>.socket</filename>,
+                <filename><replaceable>device</replaceable>.device</filename>,
+                <filename><replaceable>mount</replaceable>.mount</filename>,
+                <filename><replaceable>automount</replaceable>.automount</filename>,
+                <filename><replaceable>swap</replaceable>.swap</filename>,
+                <filename><replaceable>target</replaceable>.target</filename>,
+                <filename><replaceable>path</replaceable>.path</filename>,
+                <filename><replaceable>timer</replaceable>.timer</filename>,
+                <filename><replaceable>snapshot</replaceable>.snapshot</filename>,
+                <filename><replaceable>slice</replaceable>.slice</filename>,
+                <filename><replaceable>scope</replaceable>.scope</filename></para>
+
+                <para><literallayout><filename>/etc/systemd/system/*</filename>
+<filename>/run/systemd/system/*</filename>
+<filename>/usr/lib/systemd/system/*</filename>
+<filename>...</filename>
+                </literallayout></para>
+
+                <para><literallayout><filename>$HOME/.config/systemd/user/*</filename>
+<filename>/etc/systemd/user/*</filename>
+<filename>/run/systemd/user/*</filename>
+<filename>/usr/lib/systemd/user/*</filename>
+<filename>...</filename>
+                </literallayout></para>
         </refsynopsisdiv>
 
         <refsect1>
@@ -66,31 +84,51 @@
                 <para>A unit configuration file encodes information
                 about a service, a socket, a device, a mount point, an
                 automount point, a swap file or partition, a start-up
-                target, a file system path or a timer controlled and
-                supervised by
-                <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>. The
-                syntax is inspired by <ulink
+                target, a watched file system path, a timer controlled
+                and supervised by
+                <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+                a temporary system state snapshot, a resource
+                management slice or a group of externally created
+                processes. The syntax is inspired by <ulink
                 url="http://standards.freedesktop.org/desktop-entry-spec/latest/">XDG
-                Desktop Entry Specification</ulink> <filename>.desktop</filename> files, which are in turn
+                Desktop Entry Specification</ulink>
+                <filename>.desktop</filename> files, which are in turn
                 inspired by Microsoft Windows
                 <filename>.ini</filename> files.</para>
 
-                <para>This man pages lists the common configuration
+                <para>This man page lists the common configuration
                 options of all the unit types. These options need to
-                be configured in the [Unit] resp. [Install]
-                section of the unit files.</para>
+                be configured in the [Unit] or [Install]
+                sections of the unit files.</para>
 
                 <para>In addition to the generic [Unit] and [Install]
-                sections described here, each unit should have a
+                sections described here, each unit may have a
                 type-specific section, e.g. [Service] for a service
                 unit. See the respective man pages for more
-                information.</para>
+                information:
+                <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>systemd.snapshot</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+                <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+                <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+                </para>
+
+                <para>Unit files are loaded from a set of paths
+                determined during compilation, described in the next section.
+                </para>
 
                 <para>Unit files may contain additional options on top
                 of those listed here. If systemd encounters an unknown
-                option it will write a warning log message but
+                option, it will write a warning log message but
                 continue loading the unit. If an option is prefixed
-                with <option>X-</option> it is ignored completely by
+                with <option>X-</option>, it is ignored completely by
                 systemd. Applications may use this to include
                 additional information in the unit files.</para>
 
@@ -98,7 +136,7 @@
                 written in various formats. For positive settings the
                 strings <option>1</option>, <option>yes</option>,
                 <option>true</option> and <option>on</option> are
-                equivalent. For negative settings the strings
+                equivalent. For negative settings, the strings
                 <option>0</option>, <option>no</option>,
                 <option>false</option> and <option>off</option> are
                 equivalent.</para>
@@ -106,12 +144,14 @@
                 <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: "50" refers to 50
+                unit, the unit is honored. A concatenation of multiple
+                values with units is supported, in which case the
+                values are added up. Example: "50" refers to 50
                 seconds; "2min 200ms" refers to 2 minutes plus 200
                 milliseconds, i.e. 120200ms. The following time units
-                are understood: s, min, h, d, w, ms, us.</para>
+                are understood: s, min, h, d, w, ms, us. For details
+                see
+                <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
 
                 <para>Empty lines and lines starting with # or ; are
                 ignored. This may be used for commenting. Lines ending
@@ -119,47 +159,56 @@
                 line while reading and the backslash is replaced by a
                 space character. This may be used to wrap long lines.</para>
 
-                <para>If a line starts with <option>.include</option>
-                followed by a file name, the specified file will be
-                parsed at this point. Make sure that the file that is
-                included has the appropriate section headers before
-                any directives.</para>
-
                 <para>Along with a unit file
-                <filename>foo.service</filename> a directory
+                <filename>foo.service</filename>, the directory
                 <filename>foo.service.wants/</filename> may exist. All
-                units symlinked from such a directory are implicitly
-                added as dependencies of type
+                unit files symlinked from such a directory are
+                implicitly added as dependencies of type
                 <varname>Wanted=</varname> to the unit. This is useful
                 to hook units into the start-up of other units,
-                without having to modify their unit configuration
-                files. For details about the semantics of
-                <varname>Wanted=</varname> see below. The preferred
-                way to create symlinks in the
-                <filename>.wants/</filename> directory of a service is
-                with the <command>enable</command> command of the
+                without having to modify their unit files. For details
+                about the semantics of <varname>Wanted=</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
+                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 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 to a unit, without having to modify their
+                unit files. Make sure that the file that is included
+                has the appropriate section headers before any
+                directive.</para>
+
+                <para>If a line starts with <option>.include</option>
+                followed by a filename, the specified file will be
+                parsed at this point. Make sure that the file that is
+                included has the appropriate section headers before
+                any directives.</para>
+
                 <para>Note that while systemd offers a flexible
                 dependency system between units it is recommended to
-                use this functionality only sparsely and instead rely
+                use this functionality only sparingly and instead rely
                 on techniques such as bus-based or socket-based
-                activation which makes dependencies implicit, which
-                both results in a simpler and more flexible
-                system.</para>
+                activation which make dependencies implicit, resulting
+                in a both simpler and more flexible system.</para>
 
                 <para>Some unit names reflect paths existing in the
-                file system name space. Example: a device unit
+                file system namespace. Example: a device unit
                 <filename>dev-sda.device</filename> refers to a device
-                with the device node <filename>/dev/sda</filename> in
-                the file system namespace. If this applies a special
+                with the device node <filename noindex='true'>/dev/sda</filename> in
+                the file system namespace. If this applies, a special
                 way to escape the path name is used, so that the
-                result is usable as part of a file name. Basically,
+                result is usable as part of a filename. Basically,
                 given a path, "/" is replaced by "-", and all
                 unprintable characters and the "-" are replaced by
                 C-style "\x20" escapes. The root directory "/" is
@@ -170,12 +219,12 @@
                 <para>Optionally, units may be instantiated from a
                 template file at runtime. This allows creation of
                 multiple units from a single configuration file. If
-                systemd looks for a unit configuration file it will
+                systemd looks for a unit configuration file, it will
                 first search for the literal unit name in the
                 filesystem. If that yields no success and the unit
-                name contains an @ character, systemd will look for a
+                name contains an <literal>@</literal> character, systemd will look for a
                 unit template that shares the same name but with the
-                instance string (i.e. the part between the @ character
+                instance string (i.e. the part between the <literal>@</literal> character
                 and the suffix) removed. Example: if a service
                 <filename>getty@tty3.service</filename> is requested
                 and no file by that name is found, systemd will look
@@ -186,109 +235,113 @@
                 <para>To refer to the instance string from
                 within the configuration file you may use the special
                 <literal>%i</literal> specifier in many of the
-                configuration options. Other specifiers exist, the
-                full list is:</para>
+                configuration options. See below for details.</para>
+
+                <para>If a unit file is empty (i.e. has the file size
+                0) or is symlinked to <filename>/dev/null</filename>,
+                its configuration will not be loaded and it appears
+                with a load state of <literal>masked</literal>, and
+                cannot be activated. Use this as an effective way to
+                fully disable a unit, making it impossible to start it
+                even manually.</para>
+
+                <para>The unit file format is covered by the
+                <ulink
+                url="http://www.freedesktop.org/wiki/Software/systemd/InterfaceStabilityPromise">Interface
+                Stability Promise</ulink>.</para>
+
+        </refsect1>
+
+        <refsect1>
+                <title>Unit Load Path</title>
+
+                <para>Unit files are loaded from a set of paths
+                determined during compilation, described in the two
+                tables below. Unit files found in directories listed
+                earlier override files with the same name in
+                directories lower in the list.</para>
+
+                <para>When systemd is running in user mode
+                (<option>--user</option>) and the variable
+                <varname>$SYSTEMD_UNIT_PATH</varname> is set, this
+                contents of this variable overrides the unit load
+                path.
+                </para>
 
                 <table>
-                  <title>Specifiers available in unit files</title>
-                  <tgroup cols='3' align='left' colsep='1' rowsep='1'>
-                    <colspec colname="spec" />
-                    <colspec colname="mean" />
-                    <colspec colname="detail" />
+                  <title>
+                    Load path when running in system mode (<option>--system</option>).
+                  </title>
+
+                  <tgroup cols='2'>
+                    <colspec colname='path' />
+                    <colspec colname='expl' />
                     <thead>
                       <row>
-                        <entry>Specifier</entry>
-                        <entry>Meaning</entry>
-                        <entry>Details</entry>
+                        <entry>Path</entry>
+                        <entry>Description</entry>
                       </row>
                     </thead>
                     <tbody>
                       <row>
-                        <entry><literal>%n</literal></entry>
-                        <entry>Full unit name</entry>
-                        <entry></entry>
-                      </row>
-                      <row>
-                        <entry><literal>%N</literal></entry>
-                        <entry>Unescaped full unit name</entry>
-                        <entry></entry>
-                      </row>
-                      <row>
-                        <entry><literal>%p</literal></entry>
-                        <entry>Prefix name</entry>
-                        <entry>This refers to the string before the @, i.e. "getty" in the example above, where "tty3" is the instance name.</entry>
-                      </row>
-                      <row>
-                        <entry><literal>%P</literal></entry>
-                        <entry>Unescaped prefix name</entry>
-                        <entry></entry>
-                      </row>
-                      <row>
-                        <entry><literal>%i</literal></entry>
-                        <entry>Instance name</entry>
-                        <entry>This is the string between the @ character and the suffix.</entry>
+                        <entry><filename>/etc/systemd/system</filename></entry>
+                        <entry>Local configuration</entry>
                       </row>
                       <row>
-                        <entry><literal>%I</literal></entry>
-                        <entry>Unescaped instance name</entry>
-                        <entry></entry>
+                        <entry><filename>/run/systemd/system</filename></entry>
+                        <entry>Runtime units</entry>
                       </row>
                       <row>
-                        <entry><literal>%f</literal></entry>
-                        <entry>Unescaped file name</entry>
-                        <entry>This is either the unescaped instance name (if set) with / prepended (if necessary), or the prefix name similarly prepended with /.</entry>
-                      </row>
-                      <row>
-                        <entry><literal>%c</literal></entry>
-                        <entry>Control group path of the unit</entry>
-                        <entry></entry>
+                        <entry><filename>/usr/lib/systemd/system</filename></entry>
+                        <entry>Units of installed packages</entry>
                       </row>
+                    </tbody>
+                  </tgroup>
+                </table>
+
+                <table>
+                  <title>
+                    Load path when running in user mode (<option>--user</option>).
+                  </title>
+
+                  <tgroup cols='2'>
+                    <colspec colname='path' />
+                    <colspec colname='expl' />
+                    <thead>
                       <row>
-                        <entry><literal>%r</literal></entry>
-                        <entry>Root control group path of systemd</entry>
-                        <entry></entry>
-                      </row>
-                      <row>
-                        <entry><literal>%R</literal></entry>
-                        <entry>Parent directory of the root control group path of systemd</entry>
-                        <entry></entry>
+                        <entry>Path</entry>
+                        <entry>Description</entry>
                       </row>
+                    </thead>
+                    <tbody>
                       <row>
-                        <entry><literal>%t</literal></entry>
-                        <entry>Runtime socket dir</entry>
-                        <entry>This is either /run (for the system manager) or $XDG_RUNTIME_DIR (for user managers).</entry>
+                        <entry><filename>$HOME/.config/systemd/user</filename></entry>
+                        <entry>User configuration</entry>
                       </row>
                       <row>
-                        <entry><literal>%u</literal></entry>
-                        <entry>User name</entry>
-                        <entry>This is the name of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
+                        <entry><filename>/etc/systemd/user</filename></entry>
+                        <entry>Local configuration</entry>
                       </row>
                       <row>
-                        <entry><literal>%h</literal></entry>
-                        <entry>User home directory</entry>
-                        <entry>This is the home directory of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
+                        <entry><filename>/run/systemd/user</filename></entry>
+                        <entry>Runtime units</entry>
                       </row>
                       <row>
-                        <entry><literal>%s</literal></entry>
-                        <entry>User shell</entry>
-                        <entry>This is the shell of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
+                        <entry><filename>/usr/lib/systemd/user</filename></entry>
+                        <entry>Units of installed packages</entry>
                       </row>
                     </tbody>
                   </tgroup>
                 </table>
 
-                <para>If a unit file is empty (i.e. has the file size
-                0) or is symlinked to <filename>/dev/null</filename>
-                its configuration will not be loaded and it appears
-                with a load state of <literal>masked</literal>, and
-                cannot be activated. Use this as an effective way to
-                fully disable a unit, making it impossible to start it
-                even manually.</para>
-
-                <para>The unit file format is covered by the
+                <para>Additional units might be loaded into systemd
+                ("linked") from directories not on the unit load
+                path. See the <command>link</command> command for
+                <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. Also,
+                some units are dynamically created via generators
                 <ulink
-                url="http://www.freedesktop.org/wiki/Software/systemd/InterfaceStabilityPromise">Interface
-                Stability Promise</ulink>.</para>
+                url="http://www.freedesktop.org/wiki/Software/systemd/Generators/">Generators</ulink>.
+                </para>
         </refsect1>
 
         <refsect1>
@@ -298,7 +351,7 @@
                 carries generic information about the unit that is not
                 dependent on the type of unit:</para>
 
-                <variablelist>
+                <variablelist class='unit-directives'>
 
                         <varlistentry>
                                 <term><varname>Description=</varname></term>
@@ -306,12 +359,20 @@
                                 describing the unit. This is intended
                                 for use in UIs to show descriptive
                                 information along with the unit
-                                name.</para></listitem>
+                                name. The description should contain a name
+                                that means something to the end user.
+                                <literal>Apache2 Web Server</literal> is a good
+                                example. Bad examples are
+                                <literal>high-performance light-weight HTTP
+                                server</literal> (too generic) or
+                                <literal>Apache2</literal> (too specific and
+                                meaningless for people who do not know
+                                Apache).</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>Documentation=</varname></term>
-                                <listitem><para>A space separated list
+                                <listitem><para>A space-separated list
                                 of URIs referencing documentation for
                                 this unit or its
                                 configuration. Accepted are only URIs
@@ -322,8 +383,21 @@
                                 <literal>info:</literal>,
                                 <literal>man:</literal>. For more
                                 information about the syntax of these
-                                URIs see
-                                <citerefentry><refentrytitle>uri</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para></listitem>
+                                URIs, see
+                                <citerefentry><refentrytitle>uri</refentrytitle><manvolnum>7</manvolnum></citerefentry>. The
+                                URIs should be listed in order of
+                                relevance, starting with the most
+                                relevant. It is a good idea to first
+                                reference documentation that explains
+                                what the unit's purpose is, followed
+                                by how it is configured, followed by
+                                any other related documentation. This
+                                option may be specified more than once
+                                in which case the specified list of
+                                URIs is merged. If the empty string is
+                                assigned to this option, the list is
+                                reset and all prior assignments will
+                                have no effect.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
@@ -336,10 +410,12 @@
                                 of the other units gets deactivated or
                                 its activation fails, this unit will
                                 be deactivated. This option may be
-                                specified more than once, in which
-                                case requirement dependencies for all
-                                listed names are created. Note that
-                                requirement dependencies do not
+                                specified more than once or multiple
+                                space-separated units may be specified
+                                in one option in which case
+                                requirement dependencies for all
+                                listed names will be created. Note
+                                that requirement dependencies do not
                                 influence the order in which services
                                 are started or stopped. This has to be
                                 configured independently with the
@@ -387,7 +463,7 @@
                                 the start-up was pulled in indirectly
                                 by some dependency or automatic
                                 start-up of units that is not
-                                requested by the user this dependency
+                                requested by the user, this dependency
                                 must be fulfilled and otherwise the
                                 transaction fails. Hence, this option
                                 may be used to configure dependencies
@@ -402,22 +478,23 @@
                                 <term><varname>RequisiteOverridable=</varname></term>
 
                                 <listitem><para>Similar to
-                                <varname>Requires=</varname>
-                                resp. <varname>RequiresOverridable=</varname>. However,
-                                if a unit listed here is not started
-                                already it will not be started and the
-                                transaction fails
-                                immediately.</para></listitem>
+                                <varname>Requires=</varname> and
+                                <varname>RequiresOverridable=</varname>,
+                                respectively. However, if the units
+                                listed here are not started already
+                                they will not be started and the
+                                transaction will fail immediately.
+                                </para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>Wants=</varname></term>
 
                                 <listitem><para>A weaker version of
-                                <varname>Requires=</varname>. A unit
+                                <varname>Requires=</varname>. Units
                                 listed in this option will be started
                                 if the configuring unit is. However,
-                                if the listed unit fails to start up
+                                if the listed units fail to start
                                 or cannot be added to the transaction
                                 this has no impact on the validity of
                                 the transaction as a whole. This is
@@ -427,8 +504,8 @@
 
                                 <para>Note that dependencies of this
                                 type may also be configured outside of
-                                the unit configuration file by
-                                adding a symlink to a
+                                the unit configuration file by adding
+                                symlinks to a
                                 <filename>.wants/</filename> directory
                                 accompanying the unit file. For
                                 details see above.</para></listitem>
@@ -460,7 +537,7 @@
                                 of units. When systemd stops or restarts
                                 the units listed here, the action is
                                 propagated to this unit.
-                                Note that this is a one way dependency -
+                                Note that this is a one way dependency —
                                 changes to this unit do not affect the
                                 listed units.
                                 </para></listitem>
@@ -469,12 +546,12 @@
                         <varlistentry>
                                 <term><varname>Conflicts=</varname></term>
 
-                                <listitem><para>Configures negative
+                                <listitem><para>A space-separated list
+                                of unit names. Configures negative
                                 requirement dependencies. If a unit
-                                has a
-                                <varname>Conflicts=</varname> setting
-                                on another unit, starting the former
-                                will stop the latter and vice
+                                has a <varname>Conflicts=</varname>
+                                setting on another unit, starting the
+                                former will stop the latter and vice
                                 versa. Note that this setting is
                                 independent of and orthogonal to the
                                 <varname>After=</varname> and
@@ -501,7 +578,8 @@
                                 <term><varname>Before=</varname></term>
                                 <term><varname>After=</varname></term>
 
-                                <listitem><para>Configures ordering
+                                <listitem><para>A space-separated list
+                                of unit names. Configures ordering
                                 dependencies between units. If a unit
                                 <filename>foo.service</filename>
                                 contains a setting
@@ -550,19 +628,19 @@
                                 type <varname>After=</varname> or
                                 <varname>Before=</varname>. If two
                                 units have no ordering dependencies
-                                between them they are shut down
-                                resp. started up simultaneously, and
-                                no ordering takes
+                                between them, they are shut down or
+                                started up simultaneously, and no
+                                ordering takes
                                 place. </para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>OnFailure=</varname></term>
 
-                                <listitem><para>Lists one or more
-                                units that are activated when this
-                                unit enters the
-                                '<literal>failed</literal>'
+                                <listitem><para>A space-separated list
+                                of one or more units that are
+                                activated when this unit enters the
+                                <literal>failed</literal>
                                 state.</para></listitem>
                         </varlistentry>
 
@@ -570,23 +648,55 @@
                                 <term><varname>PropagatesReloadTo=</varname></term>
                                 <term><varname>ReloadPropagatedFrom=</varname></term>
 
-                                <listitem><para>Lists one or more
-                                units where reload requests on the
-                                unit will be propagated to/on the
-                                other unit will be propagated
-                                from. Issuing a reload request on a
-                                unit will automatically also enqueue a
-                                reload request on all units that the
-                                reload request shall be propagated to
-                                via these two
-                                settings.</para></listitem>
+                                <listitem><para>A space-separated list
+                                of one or more units where reload
+                                requests on this unit will be
+                                propagated to, or reload requests on
+                                the other unit will be propagated to
+                                this unit, respectively. Issuing a
+                                reload request on a unit will
+                                automatically also enqueue a reload
+                                request on all units that the reload
+                                request shall be propagated to via
+                                these two settings.</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><varname>JoinsNamespaceOf=</varname></term>
+
+                                <listitem><para>For units that start
+                                processes (such as service units),
+                                lists one or more other units whose
+                                network and/or temporary file
+                                namespace to join. This only applies
+                                to unit types which support the
+                                <varname>PrivateNetwork=</varname> and
+                                <varname>PrivateTmp=</varname>
+                                directives (see
+                                <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+                                for details). If a unit that has this
+                                setting set is started its processes
+                                will see the same
+                                <filename>/tmp</filename>,
+                                <filename>/tmp/var</filename> and
+                                network namespace as one listed unit
+                                that is started. If multiple listed
+                                units are already started it is not
+                                defined which namespace is
+                                joined. Note that this setting only
+                                has an effect if
+                                <varname>PrivateNetwork=</varname>
+                                and/or <varname>PrivateTmp=</varname>
+                                is enabled for both the unit that
+                                joins the namespace and the unit whose
+                                namespace is joined.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>RequiresMountsFor=</varname></term>
 
-                                <listitem><para>Takes a space
-                                separated list of absolute paths. Automatically
+                                <listitem><para>Takes a space-separated
+                                list of absolute paths. Automatically
                                 adds dependencies of type
                                 <varname>Requires=</varname> and
                                 <varname>After=</varname> for all
@@ -595,26 +705,36 @@
                         </varlistentry>
 
                         <varlistentry>
-                                <term><varname>OnFailureIsolate=</varname></term>
-
-                                <listitem><para>Takes a boolean
-                                argument. If <option>true</option> the
-                                unit listed in
+                                <term><varname>OnFailureJobMode=</varname></term>
+
+                                <listitem><para>Takes a value of
+                                <literal>fail</literal>,
+                                <literal>replace</literal>,
+                                <literal>replace-irreversibly</literal>,
+                                <literal>isolate</literal>,
+                                <literal>flush</literal>,
+                                <literal>ignore-dependencies</literal>
+                                or
+                                <literal>ignore-requirements</literal>. Defaults
+                                to
+                                <literal>replace</literal>. Specifies
+                                how the units listed in
                                 <varname>OnFailure=</varname> will be
-                                enqueued in isolation mode, i.e. all
-                                units that are not its dependency will
-                                be stopped. If this is set only a
+                                enqueued. See
+                                <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
+                                <option>--job-mode=</option> option
+                                for details on the possible values. If
+                                this is set to
+                                <literal>isolate</literal>, only a
                                 single unit may be listed in
-                                <varname>OnFailure=</varname>. Defaults
-                                to
-                                <option>false</option>.</para></listitem>
+                                <varname>OnFailure=</varname>..</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>IgnoreOnIsolate=</varname></term>
 
                                 <listitem><para>Takes a boolean
-                                argument. If <option>true</option>
+                                argument. If <option>true</option>,
                                 this unit will not be stopped when
                                 isolating another unit. Defaults to
                                 <option>false</option>.</para></listitem>
@@ -624,7 +744,7 @@
                                 <term><varname>IgnoreOnSnapshot=</varname></term>
 
                                 <listitem><para>Takes a boolean
-                                argument. If <option>true</option>
+                                argument. If <option>true</option>,
                                 this unit will not be included in
                                 snapshots. Defaults to
                                 <option>true</option> for device and
@@ -636,7 +756,7 @@
                                 <term><varname>StopWhenUnneeded=</varname></term>
 
                                 <listitem><para>Takes a boolean
-                                argument. If <option>true</option>
+                                argument. If <option>true</option>,
                                 this unit will be stopped when it is
                                 no longer used. Note that in order to
                                 minimize the work to be executed,
@@ -655,15 +775,15 @@
                                 <term><varname>RefuseManualStop=</varname></term>
 
                                 <listitem><para>Takes a boolean
-                                argument. If <option>true</option>
+                                argument. If <option>true</option>,
                                 this unit can only be activated
-                                (resp. deactivated) indirectly. In
-                                this case explicit start-up
-                                (resp. termination) requested by the
+                                or deactivated indirectly. In
+                                this case, explicit start-up
+                                or termination requested by the
                                 user is denied, however if it is
-                                started (resp. stopped) as a
+                                started or stopped as a
                                 dependency of another unit, start-up
-                                (resp. termination) will succeed. This
+                                or termination will succeed. This
                                 is mostly a safety feature to ensure
                                 that the user does not accidentally
                                 activate units that are not intended
@@ -678,10 +798,10 @@
                                 <term><varname>AllowIsolate=</varname></term>
 
                                 <listitem><para>Takes a boolean
-                                argument. If <option>true</option>
+                                argument. If <option>true</option>,
                                 this unit may be used with the
                                 <command>systemctl isolate</command>
-                                command. Otherwise this will be
+                                command. Otherwise, this will be
                                 refused. It probably is a good idea to
                                 leave this disabled except for target
                                 units that shall be used similar to
@@ -695,7 +815,7 @@
                                 <term><varname>DefaultDependencies=</varname></term>
 
                                 <listitem><para>Takes a boolean
-                                argument. If <option>true</option>
+                                argument. If <option>true</option>,
                                 (the default), a few default
                                 dependencies will implicitly be
                                 created for the unit. The actual
@@ -713,7 +833,7 @@
                                 highly recommended to leave this
                                 option enabled for the majority of
                                 common units. If set to
-                                <option>false</option> this option
+                                <option>false</option>, this option
                                 does not disable all implicit
                                 dependencies, just non-essential
                                 ones.</para></listitem>
@@ -725,10 +845,10 @@
                                 <listitem><para>When clients are
                                 waiting for a job of this unit to
                                 complete, time out after the specified
-                                time. If this time limit is reached
+                                time. If this time limit is reached,
                                 the job will be cancelled, the unit
                                 however will not change state or even
-                                enter the '<literal>failed</literal>'
+                                enter the <literal>failed</literal>
                                 mode. This value defaults to 0 (job
                                 timeouts disabled), except for device
                                 units. NB: this timeout is independent
@@ -762,11 +882,12 @@
                                 <term><varname>ConditionSecurity=</varname></term>
                                 <term><varname>ConditionCapability=</varname></term>
                                 <term><varname>ConditionHost=</varname></term>
+                                <term><varname>ConditionACPower=</varname></term>
                                 <term><varname>ConditionNull=</varname></term>
 
                                 <listitem><para>Before starting a unit
                                 verify that the specified condition is
-                                true. If it is not true the starting
+                                true. If it is not true, the starting
                                 of the unit will be skipped, however
                                 all ordering dependencies of it are
                                 still respected. A failing condition
@@ -781,12 +902,12 @@
                                 a file existence condition is
                                 checked before a unit is started. If
                                 the specified absolute path name does
-                                not exist the condition will
+                                not exist, the condition will
                                 fail. If the absolute path name passed
                                 to
                                 <varname>ConditionPathExists=</varname>
                                 is prefixed with an exclamation mark
-                                ('!'), the test is negated, and the unit
+                                (<literal>!</literal>), the test is negated, and the unit
                                 is only started if the path does not
                                 exist.</para>
 
@@ -855,7 +976,7 @@
                                 exclamation mark unset). The argument
                                 must either be a single word, or an
                                 assignment (i.e. two words, separated
-                                '='). In the former
+                                <literal>=</literal>). In the former
                                 case the kernel command line is
                                 searched for the word appearing as is,
                                 or as left hand side of an
@@ -884,13 +1005,14 @@
                                 <varname>xen</varname>,
                                 <varname>bochs</varname>,
                                 <varname>chroot</varname>,
+                                <varname>uml</varname>,
                                 <varname>openvz</varname>,
                                 <varname>lxc</varname>,
                                 <varname>lxc-libvirt</varname>,
                                 <varname>systemd-nspawn</varname> to
                                 test against a specific
                                 implementation. If multiple
-                                virtualization technologies are nested
+                                virtualization technologies are nested,
                                 only the innermost is considered. The
                                 test may be negated by prepending an
                                 exclamation mark.</para>
@@ -898,8 +1020,11 @@
                                 <para><varname>ConditionSecurity=</varname>
                                 may be used to check whether the given
                                 security module is enabled on the
-                                system.  Currently the only recognized
-                                value is <varname>selinux</varname>.
+                                system. Currently the recognized values
+                                values are <varname>selinux</varname>,
+                                <varname>apparmor</varname>,
+                                <varname>ima</varname> and
+                                <varname>smack</varname>.
                                 The test may be negated by prepending
                                 an exclamation
                                 mark.</para>
@@ -919,11 +1044,11 @@
 
                                 <para><varname>ConditionHost=</varname>
                                 may be used to match against the
-                                host name or machine ID of the
-                                host. This either takes a host name
+                                hostname or machine ID of the
+                                host. This either takes a hostname
                                 string (optionally with shell style
                                 globs) which is tested against the
-                                locally set host name as returned by
+                                locally set hostname as returned by
                                 <citerefentry><refentrytitle>gethostname</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
                                 or a machine ID formatted as string
                                 (see
@@ -931,34 +1056,55 @@
                                 The test may be negated by prepending
                                 an exclamation mark.</para>
 
+                                <para><varname>ConditionACPower=</varname>
+                                may be used to check whether the
+                                system has AC power, or is exclusively
+                                battery powered at the time of
+                                activation of the unit. This takes a
+                                boolean argument. If set to
+                                <varname>true</varname>, the condition
+                                will hold only if at least one AC
+                                connector of the system is connected
+                                to a power source, or if no AC
+                                connectors are known. Conversely, if
+                                set to <varname>false</varname>, the
+                                condition will hold only if there is
+                                at least one AC connector known and
+                                all AC connectors are disconnected
+                                from a power source.</para>
+
                                 <para>Finally,
                                 <varname>ConditionNull=</varname> may
                                 be used to add a constant condition
                                 check value to the unit. It takes a
                                 boolean argument. If set to
-                                <varname>false</varname> the condition
+                                <varname>false</varname>, the condition
                                 will always fail, otherwise
                                 succeed.</para>
 
                                 <para>If multiple conditions are
-                                specified the unit will be executed if
+                                specified, the unit will be executed if
                                 all of them apply (i.e. a logical AND
                                 is applied). Condition checks can be
                                 prefixed with a pipe symbol (|) in
                                 which case a condition becomes a
                                 triggering condition. If at least one
                                 triggering condition is defined for a
-                                unit then the unit will be executed if
+                                unit, then the unit will be executed if
                                 at least one of the triggering
                                 conditions apply and all of the
                                 non-triggering conditions. If you
                                 prefix an argument with the pipe
-                                symbol and an exclamation mark the
+                                symbol and an exclamation mark, the
                                 pipe symbol must be passed first, the
                                 exclamation second. Except for
                                 <varname>ConditionPathIsSymbolicLink=</varname>,
-                                all path checks follow
-                                symlinks.</para></listitem>
+                                all path checks follow symlinks. If
+                                any of these options is assigned the
+                                empty string, the list of conditions is
+                                reset completely, all previous
+                                condition settings (of any kind) will
+                                have no effect.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
@@ -985,57 +1131,227 @@
                 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                 tool during installation of a unit:</para>
 
-                <variablelist>
+                <variablelist class='unit-directives'>
                         <varlistentry>
                                 <term><varname>Alias=</varname></term>
 
-                                <listitem><para>Additional names this
-                                unit shall be installed under. The
-                                names listed here must have the same
-                                suffix (i.e. type) as the unit file
-                                name. This option may be specified
-                                more than once, in which case all
-                                listed names are used. At installation
-                                time,
-                                <command>systemctl enable</command>
-                                will create symlinks from these names
-                                to the unit file name.</para></listitem>
+                                <listitem><para>A space-seperated list
+                                of additional names this unit shall be
+                                installed under. The names listed here
+                                must have the same suffix (i.e. type)
+                                as the unit file name. This option may
+                                be specified more than once, in which
+                                case all listed names are used. At
+                                installation time, <command>systemctl
+                                enable</command> will create symlinks
+                                from these names to the unit
+                                filename.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>WantedBy=</varname></term>
                                 <term><varname>RequiredBy=</varname></term>
 
-                                <listitem><para>Installs a symlink in
-                                the <filename>.wants/</filename>
-                                resp. <filename>.requires/</filename>
-                                subdirectory for a unit. This has the
-                                effect that when the listed unit name
-                                is activated the unit listing it is
-                                activated
-                                too. <command>WantedBy=foo.service</command>
+                                <listitem><para>This option may be
+                                used more than once, or a
+                                space-separated list of unit names may
+                                be given. A symbolic link is created
+                                in the <filename>.wants/</filename> or
+                                <filename>.requires/</filename>
+                                directory of each of the listed units
+                                when this unit is installed by
+                                <command>systemctl enable</command>.
+                                This has the effect that a dependency
+                                of type <varname>Wants=</varname> or
+                                <varname>Requires=</varname> is added
+                                from the listed unit to the current
+                                unit. The primary result is that the
+                                current unit will be started when the
+                                listed unit is started. See the
+                                description of
+                                <varname>Wants=</varname> and
+                                <varname>Requires=</varname> in the
+                                [Unit] section for details.</para>
+
+                                <para><command>WantedBy=foo.service</command>
                                 in a service
                                 <filename>bar.service</filename> is
                                 mostly equivalent to
                                 <command>Alias=foo.service.wants/bar.service</command>
-                                in the same file.</para></listitem>
+                                in the same file. In case of template
+                                units, <command>systemctl enable</command>
+                                must be called with an instance name, and
+                                this instance will be added to the
+                                <filename>.wants/</filename> or
+                                <filename>.requires/</filename> list
+                                of the listed unit.
+                                E.g. <command>WantedBy=getty.target</command>
+                                in a service
+                                <filename>getty@.service</filename>
+                                will result in <command>systemctl
+                                enable getty@tty2.service</command>
+                                creating a
+                                <filename>getty.target.wants/getty@tty2.service</filename>
+                                link to <filename>getty@.service</filename>.
+                                </para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>Also=</varname></term>
 
                                 <listitem><para>Additional units to
-                                install when this unit is
-                                installed. If the user requests
-                                installation of a unit with this
-                                option configured,
+                                install/deinstall when this unit is
+                                installed/deinstalled. If the user
+                                requests installation/deinstallation
+                                of a unit with this option configured,
                                 <command>systemctl enable</command>
-                                will automatically install units
-                                listed in this option as
-                                well.</para></listitem>
+                                and <command>systemctl
+                                disable</command> will automatically
+                                install/uninstall units listed in this option as
+                                well.</para>
+
+                                <para>This option may be used more
+                                than once, or a space-separated list
+                                of unit names may be
+                                given.</para></listitem>
                         </varlistentry>
                 </variablelist>
 
+                <para>The following specifiers are interpreted in the
+                Install section: %n, %N, %p, %i, %U, %u, %m, %H, %b, %v.
+                For their meaning see the next section.
+                </para>
+        </refsect1>
+
+        <refsect1>
+                <title>Specifiers</title>
+
+                <para>Many settings resolve specifiers which may be
+                used to write generic unit files referring to runtime
+                or unit parameters that are replaced when the unit
+                files are loaded. The following specifiers are
+                understood:</para>
+
+                <table>
+                  <title>Specifiers available in unit files</title>
+                  <tgroup cols='3' align='left' colsep='1' rowsep='1'>
+                    <colspec colname="spec" />
+                    <colspec colname="mean" />
+                    <colspec colname="detail" />
+                    <thead>
+                      <row>
+                        <entry>Specifier</entry>
+                        <entry>Meaning</entry>
+                        <entry>Details</entry>
+                      </row>
+                    </thead>
+                    <tbody>
+                      <row>
+                        <entry><literal>%n</literal></entry>
+                        <entry>Full unit name</entry>
+                        <entry></entry>
+                      </row>
+                      <row>
+                        <entry><literal>%N</literal></entry>
+                        <entry>Unescaped full unit name</entry>
+                        <entry></entry>
+                      </row>
+                      <row>
+                        <entry><literal>%p</literal></entry>
+                        <entry>Prefix name</entry>
+                        <entry>For instantiated units this refers to the string before the @. For non-instantiated units this refers to to the name of the unit with the type suffix removed.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%P</literal></entry>
+                        <entry>Unescaped prefix name</entry>
+                        <entry></entry>
+                      </row>
+                      <row>
+                        <entry><literal>%i</literal></entry>
+                        <entry>Instance name</entry>
+                        <entry>For instantiated units: this is the string between the <literal>@</literal> character and the suffix.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%I</literal></entry>
+                        <entry>Unescaped instance name</entry>
+                        <entry></entry>
+                      </row>
+                      <row>
+                        <entry><literal>%f</literal></entry>
+                        <entry>Unescaped filename</entry>
+                        <entry>This is either the unescaped instance name (if applicable) with <filename>/</filename> prepended (if applicable), or the prefix name similarly prepended with <filename>/</filename>.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%c</literal></entry>
+                        <entry>Control group path of the unit</entry>
+                        <entry></entry>
+                      </row>
+                      <row>
+                        <entry><literal>%r</literal></entry>
+                        <entry>Root control group path where units are placed.</entry>
+                        <entry>For system instances, this usually resolves to <filename>/system</filename>, except in containers, where the path might be prefixed with the container's root control group.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%R</literal></entry>
+                        <entry>Parent directory of the control group path where units are placed.</entry>
+                        <entry>For system instances, this usually
+                        resolves to <filename>/</filename>, except in
+                        containers, where this resolves to the
+                        container's root directory.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%t</literal></entry>
+                        <entry>Runtime socket dir</entry>
+                        <entry>This is either <filename>/run</filename> (for the system manager) or <literal>$XDG_RUNTIME_DIR</literal> (for user managers).</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%u</literal></entry>
+                        <entry>User name</entry>
+                        <entry>This is the name of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%U</literal></entry>
+                        <entry>User UID</entry>
+                        <entry>This is the UID of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%h</literal></entry>
+                        <entry>User home directory</entry>
+                        <entry>This is the home directory of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%s</literal></entry>
+                        <entry>User shell</entry>
+                        <entry>This is the shell of the configured user of the unit, or (if none is set) the user running the systemd instance.  If the user is <literal>root</literal> (UID equal to 0), the shell configured in account database is ignored and <filename>/bin/sh</filename> is always used.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%m</literal></entry>
+                        <entry>Machine ID</entry>
+                        <entry>The machine ID of the running system, formatted as string. See <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%b</literal></entry>
+                        <entry>Boot ID</entry>
+                        <entry>The boot ID of the running system, formatted as string. See <citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry> for more information.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%H</literal></entry>
+                        <entry>Host name</entry>
+                        <entry>The hostname of the running system.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%v</literal></entry>
+                        <entry>Kernel release</entry>
+                        <entry>Identical to <command>uname -r</command> output.</entry>
+                      </row>
+                      <row>
+                        <entry><literal>%%</literal></entry>
+                        <entry>Escaped %</entry>
+                        <entry>Single percent sign.</entry>
+                      </row>
+                    </tbody>
+                  </tgroup>
+                </table>
         </refsect1>
 
         <refsect1>
@@ -1054,7 +1370,12 @@
                         <citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>systemd.snapshot</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
-                        <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+                        <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>uname</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                 </para>
         </refsect1>