Restore shared XML files.

* man/less-variables.xml,
  man/standard-conf.xml,
  man/standard-options.xml,
  man/user-system-options.xml: Restore files from upstream (removed in
  commit d3ad6bf3).

1 files changed, 71 insertions, 0 deletions

diff --git a/man/standard-conf.xml b/man/standard-conf.xml
new file mode 100644
index 0000000000..004f53f70c
--- /dev/null
+++ b/man/standard-conf.xml
@@ -0,0 +1,71 @@
+<?xml version="1.0"?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
+<!DOCTYPE refsection PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+          "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
+
+<refsection>
+  <refsection id='confd'>
+    <title>Configuration Directories and Precedence</title>
+
+    <para>Configuration files are read from directories in
+    <filename>/etc/</filename>, <filename>/run/</filename>, and
+    <filename>/usr/lib/</filename>, in order of precedence.
+    Each configuration file in these configuration directories shall be named in
+    the style of <filename><replaceable>filename</replaceable>.conf</filename>.
+    Files in <filename>/etc/</filename> override files with the same name in
+    <filename>/run/</filename> and <filename>/usr/lib/</filename>. Files in
+    <filename>/run/</filename> override files with the same name in
+    <filename>/usr/lib/</filename>.</para>
+
+    <para>Packages should install their configuration files in
+    <filename>/usr/lib/</filename>. Files in <filename>/etc/</filename> are
+    reserved for the local administrator, who may use this logic to override the
+    configuration files installed by vendor packages. All configuration files
+    are sorted by their filename in lexicographic order, regardless of which of
+    the directories they reside in. If multiple files specify the same option,
+    the entry in the file with the lexicographically latest name will take
+    precedence. It is recommended to prefix all filenames with a two-digit number
+    and a dash, to simplify the ordering of the files.</para>
+
+    <para>If the administrator wants to disable a configuration file supplied by
+    the vendor, the recommended way is to place a symlink to
+    <filename>/dev/null</filename> in the configuration directory in
+    <filename>/etc/</filename>, with the same filename as the vendor
+    configuration file.</para>
+  </refsection>
+
+  <refsection id='main-conf'>
+    <title>Configuration Directories and Precedence</title>
+
+    <para>Default configuration is defined during compilation, so a
+    configuration file is only needed when it is necessary to deviate
+    from those defaults. By default the configuration file in
+    <filename>/etc/systemd/</filename> contains commented out entries
+    showing the defaults as a guide to the administrator. This file
+    can be edited to create local overrides.
+    </para>
+
+    <para>When packages need to customize the configuration, they can
+    install configuration snippets in
+    <filename>/usr/lib/systemd/*.conf.d/</filename>. Files in
+    <filename>/etc/</filename> are reserved for the local
+    administrator, who may use this logic to override the
+    configuration files installed by vendor packages. The main
+    configuration file is read before any of the configuration
+    directories, and has the lowest precedence; entries in a file in
+    any configuration directory override entries in the single
+    configuration file. Files in the
+    <filename>*.conf.d/</filename> configuration subdirectories
+    are sorted by their filename in lexicographic order, regardless of
+    which of the subdirectories they reside in. If multiple files
+    specify the same option, the entry in the file with the
+    lexicographically latest name takes precedence.  It is recommended
+    to prefix all filenames in those subdirectories with a two-digit
+    number and a dash, to simplify the ordering of the files.</para>
+
+    <para>To disable a configuration file supplied by the vendor, the
+    recommended way is to place a symlink to
+    <filename>/dev/null</filename> in the configuration directory in
+    <filename>/etc/</filename>, with the same filename as the vendor
+    configuration file.</para>
+  </refsection>
+</refsection>