<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>nix-channel</refentrytitle> <manvolnum>1</manvolnum> <refmiscinfo class="source">Nix</refmiscinfo> <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo> </refmeta> <refnamediv> <refname>nix-channel</refname> <refpurpose>manage Nix channels</refpurpose> </refnamediv> <refsynopsisdiv> <cmdsynopsis> <command>nix-channel</command> <group choice='req'> <arg choice='plain'><option>--add</option> <replaceable>url</replaceable></arg> <arg choice='plain'><option>--remove</option> <replaceable>url</replaceable></arg> <arg choice='plain'><option>--list</option></arg> <arg choice='plain'><option>--update</option></arg> </group> </cmdsynopsis> </refsynopsisdiv> <refsection><title>Description</title> <para>A Nix channel is mechanism that allows you to automatically stay up-to-date with a set of pre-built Nix expressions. A Nix channel is just a URL that points to a place that contains a set of Nix expressions, as well as a <command>nix-push</command> manifest. See also <xref linkend="sec-channels" />.</para> <para>This command has the following operations: <variablelist> <varlistentry><term><option>--add</option> <replaceable>url</replaceable></term> <listitem><para>Adds <replaceable>url</replaceable> to the list of subscribed channels.</para></listitem> </varlistentry> <varlistentry><term><option>--remove</option> <replaceable>url</replaceable></term> <listitem><para>Removes <replaceable>url</replaceable> from the list of subscribed channels.</para></listitem> </varlistentry> <varlistentry><term><option>--list</option></term> <listitem><para>Prints the URLs of all subscribed channels on standard output.</para></listitem> </varlistentry> <varlistentry><term><option>--update</option></term> <listitem><para>Downloads the Nix expressions of all subscribed channels, makes them the default for <command>nix-env</command> operations (by symlinking them in the directory <filename>~/.nix-defexpr</filename>), and performs a <command>nix-pull</command> on the manifests of all channels to make pre-built binaries available.</para></listitem> </varlistentry> </variablelist> </para> <para>Note that <option>--add</option> and <option>--remove</option> do not automatically perform an update.</para> <para>The list of subscribed channels is stored in <filename>~/.nix-channels</filename>.</para> <para>A channel consists of two elements: a bzipped Tar archive containing the Nix expressions, and a manifest created by <command>nix-push</command>. These must be stored under <literal><replaceable>url</replaceable>/nixexprs.tar.bz2</literal> and <literal><replaceable>url</replaceable>/MANIFEST</literal>, respectively.</para> </refsection> </refentry>