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+<refentry xmlns="http://docbook.org/ns/docbook"
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
+ <refmeta>
+  <refentrytitle><command>nixos-option</command>
+  </refentrytitle><manvolnum>8</manvolnum>
+  <refmiscinfo class="source">NixOS</refmiscinfo>
+<!-- <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo> -->
+ </refmeta>
+ <refnamediv>
+  <refname><command>nixos-option</command></refname>
+  <refpurpose>inspect a NixOS configuration</refpurpose>
+ </refnamediv>
+ <refsynopsisdiv>
+  <cmdsynopsis>
+   <command>nixos-option</command>
+
+   <arg>
+    <group choice='req'>
+     <arg choice='plain'><option>-r</option></arg>
+     <arg choice='plain'><option>--recursive</option></arg>
+    </group>
+   </arg>
+
+   <arg>
+    <option>-I</option> <replaceable>path</replaceable>
+   </arg>
+
+   <arg>
+    <replaceable>option.name</replaceable>
+   </arg>
+  </cmdsynopsis>
+ </refsynopsisdiv>
+ <refsection>
+  <title>Description</title>
+  <para>
+   This command evaluates the configuration specified in
+   <filename>/etc/nixos/configuration.nix</filename> and returns the properties
+   of the option name given as argument.
+  </para>
+  <para>
+   When the option name is not an option, the command prints the list of
+   attributes contained in the attribute set.
+  </para>
+ </refsection>
+ <refsection>
+  <title>Options</title>
+  <para>
+   This command accepts the following options:
+  </para>
+  <variablelist>
+   <varlistentry>
+    <term><option>-r</option></term>
+    <term><option>--recursive</option></term>
+    <listitem>
+     <para>
+      Print all the values at or below the specified path recursively.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <option>-I</option> <replaceable>path</replaceable>
+    </term>
+    <listitem>
+     <para>
+      This option is passed to the underlying
+      <command>nix-instantiate</command> invocation.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+ </refsection>
+ <refsection>
+  <title>Environment</title>
+  <variablelist>
+   <varlistentry>
+    <term>
+     <envar>NIXOS_CONFIG</envar>
+    </term>
+    <listitem>
+     <para>
+      Path to the main NixOS configuration module. Defaults to
+      <filename>/etc/nixos/configuration.nix</filename>.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+ </refsection>
+ <refsection>
+  <title>Examples</title>
+  <para>
+   Investigate option values:
+<screen><prompt>$ </prompt>nixos-option boot.loader
+This attribute set contains:
+generationsDir
+grub
+initScript
+
+<prompt>$ </prompt>nixos-option boot.loader.grub.enable
+Value:
+true
+
+Default:
+true
+
+Description:
+Whether to enable the GNU GRUB boot loader.
+
+Declared by:
+  "/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/nixos/modules/system/boot/loader/grub/grub.nix"
+
+Defined by:
+  "/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/nixos/modules/system/boot/loader/grub/grub.nix"
+</screen>
+  </para>
+ </refsection>
+ <refsection>
+  <title>Bugs</title>
+  <para>
+   The author listed in the following section is wrong. If there is any other
+   bug, please report to Nicolas Pierron.
+  </para>
+ </refsection>
+ <refsection>
+  <title>See also</title>
+  <para>
+   <citerefentry>
+    <refentrytitle>configuration.nix</refentrytitle>
+    <manvolnum>5</manvolnum>
+   </citerefentry>
+  </para>
+ </refsection>
+</refentry>