mirror of
https://github.com/privatevoid-net/nix-super.git
synced 2024-11-27 00:06:16 +02:00
241 lines
7.7 KiB
XML
241 lines
7.7 KiB
XML
<refentry xmlns="http://docbook.org/ns/docbook"
|
||
xmlns:xlink="http://www.w3.org/1999/xlink"
|
||
xmlns:xi="http://www.w3.org/2001/XInclude"
|
||
xml:id="sec-nix-instantiate">
|
||
|
||
<refmeta>
|
||
<refentrytitle>nix-instantiate</refentrytitle>
|
||
<manvolnum>1</manvolnum>
|
||
<refmiscinfo class="source">Nix</refmiscinfo>
|
||
<refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
|
||
</refmeta>
|
||
|
||
<refnamediv>
|
||
<refname>nix-instantiate</refname>
|
||
<refpurpose>instantiate store derivations from Nix expressions</refpurpose>
|
||
</refnamediv>
|
||
|
||
<refsynopsisdiv>
|
||
<cmdsynopsis>
|
||
<command>nix-instantiate</command>
|
||
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
|
||
<arg><option>--arg</option> <replaceable>name</replaceable> <replaceable>value</replaceable></arg>
|
||
<arg>
|
||
<group choice='req'>
|
||
<arg choice='plain'><option>--attr</option></arg>
|
||
<arg choice='plain'><option>-A</option></arg>
|
||
</group>
|
||
<replaceable>attrPath</replaceable>
|
||
</arg>
|
||
<arg><option>--add-root</option> <replaceable>path</replaceable></arg>
|
||
<arg><option>--indirect</option></arg>
|
||
<arg>
|
||
<group choice='req'>
|
||
<arg choice='plain'><option>--parse-only</option></arg>
|
||
<arg choice='plain'>
|
||
<option>--eval-only</option>
|
||
<arg><option>--strict</option></arg>
|
||
<arg><option>--read-write-mode</option></arg>
|
||
</arg>
|
||
<arg choice='plain'><option>--find-file</option></arg>
|
||
</group>
|
||
<arg><option>--xml</option></arg>
|
||
</arg>
|
||
<arg choice='plain' rep='repeat'><replaceable>files</replaceable></arg>
|
||
</cmdsynopsis>
|
||
</refsynopsisdiv>
|
||
|
||
|
||
<refsection><title>Description</title>
|
||
|
||
<para>The command <command>nix-instantiate</command> generates <link
|
||
linkend="gloss-derivation">store derivations</link> from (high-level)
|
||
Nix expressions. It loads and evaluates the Nix expressions in each
|
||
of <replaceable>files</replaceable> (which defaults to
|
||
<replaceable>./default.nix</replaceable>). Each top-level expression
|
||
should evaluate to a derivation, a list of derivations, or a set of
|
||
derivations. The paths of the resulting store derivations are printed
|
||
on standard output.</para>
|
||
|
||
<para>If <replaceable>files</replaceable> is the character
|
||
<literal>-</literal>, then a Nix expression will be read from standard
|
||
input.</para>
|
||
|
||
<para>Most users and developers don’t need to use this command
|
||
(<command>nix-env</command> and <command>nix-build</command> perform
|
||
store derivation instantiation from Nix expressions automatically).
|
||
It is most commonly used for implementing new deployment
|
||
policies.</para>
|
||
|
||
<para condition="manual">See also <xref linkend="sec-common-options"
|
||
/> for a list of common options.</para>
|
||
|
||
</refsection>
|
||
|
||
|
||
<refsection><title>Options</title>
|
||
|
||
<variablelist>
|
||
|
||
<varlistentry>
|
||
<term><option>--add-root</option> <replaceable>path</replaceable></term>
|
||
<term><option>--indirect</option></term>
|
||
|
||
<listitem><para>See the <link linkend="opt-add-root">corresponding
|
||
options</link> in <command>nix-store</command>.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
|
||
<varlistentry><term><option>--parse-only</option></term>
|
||
|
||
<listitem><para>Just parse the input files, and print their
|
||
abstract syntax trees on standard output in ATerm
|
||
format.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
<varlistentry><term><option>--eval-only</option></term>
|
||
|
||
<listitem><para>Just parse and evaluate the input files, and print
|
||
the resulting values on standard output. No instantiation of
|
||
store derivations takes place.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
<varlistentry><term><option>--find-file</option></term>
|
||
|
||
<listitem><para>Look up the given files in Nix’s search path (as
|
||
specified by the <envar>NIX_PATH</envar> environment variable).
|
||
If found, print the corresponding absolute paths on standard
|
||
output. For instance, if <envar>NIX_PATH</envar> is
|
||
<literal>nixpkgs=/home/alice/nixpkgs</literal>, then
|
||
<literal>nix-instantiate --find-file nixpkgs/default.nix</literal>
|
||
will print
|
||
<literal>/home/alice/nixpkgs/default.nix</literal>.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
<varlistentry><term><option>--xml</option></term>
|
||
|
||
<listitem><para>When used with <option>--parse-only</option> and
|
||
<option>--eval-only</option>, print the resulting expression as an
|
||
XML representation of the abstract syntax tree rather than as an
|
||
ATerm. The schema is the same as that used by the <link
|
||
linkend="builtin-toXML"><function>toXML</function>
|
||
built-in</link>.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
<varlistentry><term><option>--strict</option></term>
|
||
|
||
<listitem><para>When used with <option>--eval-only</option>,
|
||
recursively evaluate list elements and attributes. Normally, such
|
||
sub-expressions are left unevaluated (since the Nix expression
|
||
language is lazy).</para>
|
||
|
||
<warning><para>This option can cause non-termination, because lazy
|
||
data structures can be infinitely large.</para></warning>
|
||
|
||
</listitem>
|
||
|
||
</varlistentry>
|
||
|
||
<varlistentry><term><option>--read-write-mode</option></term>
|
||
|
||
<listitem><para>When used with <option>--eval-only</option>,
|
||
perform evaluation in read/write mode so nix language features
|
||
that require it will still work (at the cost of needing to do
|
||
instantiation of every evaluated derivation).</para>
|
||
|
||
</listitem>
|
||
|
||
</varlistentry>
|
||
|
||
</variablelist>
|
||
|
||
<variablelist condition="manpage">
|
||
<xi:include href="opt-common.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(//db:variablelist[@xml:id='opt-common']/*)" />
|
||
</variablelist>
|
||
|
||
</refsection>
|
||
|
||
|
||
<refsection><title>Examples</title>
|
||
|
||
<para>Instantiating store derivations from a Nix expression, and
|
||
building them using <command>nix-store</command>:
|
||
|
||
<screen>
|
||
$ nix-instantiate test.nix <lineannotation>(instantiate)</lineannotation>
|
||
/nix/store/cigxbmvy6dzix98dxxh9b6shg7ar5bvs-perl-BerkeleyDB-0.26.drv
|
||
|
||
$ nix-store -r $(nix-instantiate test.nix) <lineannotation>(build)</lineannotation>
|
||
<replaceable>...</replaceable>
|
||
/nix/store/qhqk4n8ci095g3sdp93x7rgwyh9rdvgk-perl-BerkeleyDB-0.26 <lineannotation>(output path)</lineannotation>
|
||
|
||
$ ls -l /nix/store/qhqk4n8ci095g3sdp93x7rgwyh9rdvgk-perl-BerkeleyDB-0.26
|
||
dr-xr-xr-x 2 eelco users 4096 1970-01-01 01:00 lib
|
||
...</screen>
|
||
|
||
</para>
|
||
|
||
<para>Parsing and evaluating Nix expressions:
|
||
|
||
<screen>
|
||
$ echo '"foo" + "bar"' | nix-instantiate --parse-only -
|
||
OpPlus(Str("foo"),Str("bar"))
|
||
|
||
$ echo '"foo" + "bar"' | nix-instantiate --eval-only -
|
||
Str("foobar")
|
||
|
||
$ echo '"foo" + "bar"' | nix-instantiate --eval-only --xml -
|
||
<![CDATA[<?xml version='1.0' encoding='utf-8'?>
|
||
<expr>
|
||
<string value="foobar" />
|
||
</expr>]]></screen>
|
||
|
||
</para>
|
||
|
||
<para>The difference between non-strict and strict evaluation:
|
||
|
||
<screen>
|
||
$ echo 'rec { x = "foo"; y = x; }' | nix-instantiate --eval-only --xml -
|
||
<replaceable>...</replaceable><![CDATA[
|
||
<attr name="x">
|
||
<string value="foo" />
|
||
</attr>
|
||
<attr name="y">
|
||
<unevaluated />
|
||
</attr>]]>
|
||
<replaceable>...</replaceable></screen>
|
||
|
||
Note that <varname>y</varname> is left unevaluated (the XML
|
||
representation doesn’t attempt to show non-normal forms).
|
||
|
||
<screen>
|
||
$ echo 'rec { x = "foo"; y = x; }' | nix-instantiate --eval-only --xml --strict -
|
||
<replaceable>...</replaceable><![CDATA[
|
||
<attr name="x">
|
||
<string value="foo" />
|
||
</attr>
|
||
<attr name="y">
|
||
<string value="foo" />
|
||
</attr>]]>
|
||
<replaceable>...</replaceable></screen>
|
||
|
||
</para>
|
||
|
||
</refsection>
|
||
|
||
|
||
<refsection condition="manpage"><title>Environment variables</title>
|
||
|
||
<variablelist>
|
||
<xi:include href="env-common.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(//db:variablelist[@xml:id='env-common']/*)" />
|
||
</variablelist>
|
||
|
||
</refsection>
|
||
|
||
|
||
</refentry>
|