<chapter xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-configuration-syntax">

<title>Configuration Syntax</title>

<para>The NixOS configuration file
<filename>/etc/nixos/configuration.nix</filename> is actually a
<emphasis>Nix expression</emphasis>, which is the Nix package
manager’s purely functional language for describing how to build
packages and configurations.  This means you have all the expressive
power of that language at your disposal, including the ability to
abstract over common patterns, which is very useful when managing
complex systems.  The syntax and semantics of the Nix language are
fully described in the <link
xlink:href="http://nixos.org/nix/manual/#chap-writing-nix-expressions">Nix
manual</link>, but here we give a short overview of the most important
constructs useful in NixOS configuration files.</para>

<xi:include href="config-file.xml" />
<xi:include href="abstractions.xml" />
<xi:include href="modularity.xml" />
<xi:include href="summary.xml" />

</chapter>
