man: reword list-dependencies description

The previous version was a bit too vague. It is better
to simply list all dependency types that are followed.

Previous version also made an emphasis on dependencies introduced by
configuration.  But this command (or systemd) don't care about this
distinction between configured and automatically added dependencies at
all. This distinctionis removed from the main description, and an
explanatory paragraph is added to remind the user that all
dependencies are shown, no matter where they come from.

1 files changed, 44 insertions, 18 deletions

diff --git a/man/systemctl.xml b/man/systemctl.xml
index 033160329e..4a7abab8a4 100644
--- a/man/systemctl.xml
+++ b/man/systemctl.xml
@@ -151,9 +151,12 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>.
 
         <listitem>
           <para>Show reverse dependencies between units with
-          <command>list-dependencies</command>, i.e. units with
-          dependencies of type <varname>Wants=</varname> or
-          <varname>Requires=</varname> on the given unit.
+          <command>list-dependencies</command>, i.e. follow
+          dependencies of type <varname>WantedBy=</varname>,
+          <varname>RequiredBy=</varname>,
+          <varname>RequiredByOverrridable=</varname>,
+          <varname>PartOf=</varname>, <varname>BoundBy=</varname>,
+          instead of <varname>Wants=</varname> and similar.
           </para>
         </listitem>
       </varlistentry>
@@ -164,10 +167,20 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>.
         <listitem>
           <para>With <command>list-dependencies</command>, show the
           units that are ordered before the specified unit. In other
-          words, list the units that are in the <varname>After=</varname>
-          directive of the specified unit, have the specified unit in
-          their <varname>Before=</varname> directive, or are otherwise
-          implicit dependencies of the specified unit.</para>
+          words, recursively list units following the
+          <varname>After=</varname> dependency.</para>
+
+          <para>Note that any <varname>After=</varname> dependency is
+          automatically mirrored to create a
+          <varname>Before=</varname> dependency. Temporal dependencies
+          may be specified explictly, but are also created implicitly
+          for units which are <varname>WantedBy=</varname> targets
+          (see
+          <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>),
+          and as a result of other directives (for example
+          <varname>RequiresMountsFor=</varname>). Both explicitly
+          and implicitly introduced dependencies are shown with
+          <command>list-dependencies</command>.</para>
         </listitem>
       </varlistentry>
 
@@ -177,10 +190,8 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>.
         <listitem>
           <para>With <command>list-dependencies</command>, show the
           units that are ordered after the specified unit. In other
-          words, list the units that are in the <varname>Before=</varname>
-          directive of the specified unit, have the specified unit in
-          their <varname>After=</varname> directive, or otherwise depend
-          on the specified unit.</para>
+          words, recursively list units following the
+          <varname>Before=</varname> dependency.</para>
         </listitem>
       </varlistentry>
 
@@ -848,15 +859,30 @@ kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
         </varlistentry>
 
         <varlistentry>
-          <term><command>list-dependencies <replaceable>NAME</replaceable></command></term>
+          <term>
+            <command>list-dependencies</command>
+            <optional><replaceable>NAME</replaceable></optional>
+          </term>
 
           <listitem>
-            <para>Shows required and wanted units of the specified
-            unit. If no unit is specified,
-            <filename>default.target</filename> is implied. Target units
-            are recursively expanded.  When <option>--all</option> is
-            passed, all other units are recursively expanded as
-            well.</para>
+            <para>Shows units required and wanted by the specified
+            unit. This recursively lists units following the
+            <varname>Requires=</varname>,
+            <varname>RequiresOverridable=</varname>,
+            <varname>Requisite=</varname>,
+            <varname>RequisiteOverridable=</varname>,
+            <varname>Wants=</varname>, <varname>BindsTo=</varname>
+            dependencies. If no unit is specified,
+            <filename>default.target</filename> is implied.</para>
+
+            <para>By default, only target units are recursively
+            expanded. When <option>--all</option> is passed, all other
+            units are recursively expanded as well.</para>
+
+            <para>Options <option>--reverse</option>,
+            <option>--after</option>, <option>--before</option>
+            may be used to change what types of dependencies
+            are shown.</para>
           </listitem>
         </varlistentry>
       </variablelist>