47 lines
1.7 KiB
XML
47 lines
1.7 KiB
XML
<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="ch-simple-expression">
|
|
|
|
<title>A Simple Nix Expression</title>
|
|
|
|
<para>This section shows how to add and test the <link
|
|
xlink:href='http://www.gnu.org/software/hello/hello.html'>GNU Hello
|
|
package</link> to the Nix Packages collection. Hello is a program
|
|
that prints out the text <quote>Hello, world!</quote>.</para>
|
|
|
|
<para>To add a package to the Nix Packages collection, you generally
|
|
need to do three things:
|
|
|
|
<orderedlist>
|
|
|
|
<listitem><para>Write a Nix expression for the package. This is a
|
|
file that describes all the inputs involved in building the package,
|
|
such as dependencies, sources, and so on.</para></listitem>
|
|
|
|
<listitem><para>Write a <emphasis>builder</emphasis>. This is a
|
|
shell script<footnote><para>In fact, it can be written in any
|
|
language, but typically it's a <command>bash</command> shell
|
|
script.</para></footnote> that actually builds the package from
|
|
the inputs.</para></listitem>
|
|
|
|
<listitem><para>Add the package to the file
|
|
<filename>pkgs/top-level/all-packages.nix</filename>. The Nix
|
|
expression written in the first step is a
|
|
<emphasis>function</emphasis>; it requires other packages in order
|
|
to build it. In this step you put it all together, i.e., you call
|
|
the function with the right arguments to build the actual
|
|
package.</para></listitem>
|
|
|
|
</orderedlist>
|
|
|
|
</para>
|
|
|
|
<xi:include href="expression-syntax.xml" />
|
|
<xi:include href="build-script.xml" />
|
|
<xi:include href="arguments-variables.xml" />
|
|
<xi:include href="simple-building-testing.xml" />
|
|
<xi:include href="generic-builder.xml" />
|
|
|
|
</chapter>
|