forked from lix-project/lix
* Manual updates.
This commit is contained in:
parent
7b0e29b4dc
commit
dc05f29cf6
|
@ -1,7 +1,9 @@
|
|||
ENV = SGML_CATALOG_FILES=$(docbookcatalog)
|
||||
|
||||
XMLLINT = $(ENV) $(xmllint) $(xmlflags) --catalogs
|
||||
XSLTPROC = $(ENV) $(xsltproc) $(xmlflags) --catalogs
|
||||
XSLTPROC = $(ENV) $(xsltproc) $(xmlflags) --catalogs \
|
||||
--param section.autolabel 1 \
|
||||
--param section.label.includes.component.label 1
|
||||
|
||||
SOURCES = book.xml introduction.xml installation.xml \
|
||||
overview.xml \
|
||||
|
|
|
@ -117,7 +117,7 @@ $ autoreconf -i</screen>
|
|||
|
||||
<para>
|
||||
To use Nix, some environment variables should be set. In particular,
|
||||
<literal>PATH</literal> should contain the directories
|
||||
<envar>PATH</envar> should contain the directories
|
||||
<filename><replaceable>prefix</replaceable>/bin</filename> and
|
||||
<filename><replaceable>prefix</replaceable>/var/nix/links/current/bin</filename>.
|
||||
The first directory contains the Nix tools themselves, while the second
|
||||
|
|
|
@ -14,10 +14,9 @@
|
|||
installed or available for installation, and so on. These are operations
|
||||
on the <emphasis>user environment</emphasis>: the set of packages that a
|
||||
user <quote>sees</quote>. In a command line Unix environment, this means
|
||||
the set of programs that are available through the
|
||||
<literal>PATH</literal> environment variable. (In other environments it
|
||||
might mean the set of programs available on the desktop, through the
|
||||
start menu, and so on.)
|
||||
the set of programs that are available through the <envar>PATH</envar>
|
||||
environment variable. (In other environments it might mean the set of
|
||||
programs available on the desktop, through the start menu, and so on.)
|
||||
</para>
|
||||
|
||||
<para>
|
||||
|
@ -183,8 +182,8 @@ obtaining list of Nix archives at http://losser.st-lab.cs.uu.nl/~eelco/nix-dist.
|
|||
<para>
|
||||
Assuming that the <literal>pan</literal> installation produced no errors,
|
||||
it can be used immediately, that is, it now appears in a directory in the
|
||||
<literal>PATH</literal> environment variable. Specifically,
|
||||
<literal>PATH</literal> includes the entry
|
||||
<envar>PATH</envar> environment variable. Specifically,
|
||||
<envar>PATH</envar> includes the entry
|
||||
<filename><replaceable>prefix</replaceable>/var/nix/links/current/bin</filename>,
|
||||
where
|
||||
<filename><replaceable>prefix</replaceable>/var/nix/links/current</filename>
|
||||
|
@ -239,6 +238,172 @@ $ nix-env -u pan-0.14.2</screen>
|
|||
|
||||
</sect1>
|
||||
|
||||
|
||||
<sect1>
|
||||
<title>Writing Nix expressions</title>
|
||||
|
||||
<sect2>
|
||||
<title>A simple Nix expression</title>
|
||||
|
||||
<para>
|
||||
This section shows how to write simple Nix expressions—the things
|
||||
that describe how to build a package.
|
||||
</para>
|
||||
|
||||
<example id='ex-hello-nix'>
|
||||
<title>Nix expression for GNU Hello</title>
|
||||
<programlisting>
|
||||
{stdenv, fetchurl, perl}: <co id='ex-hello-nix-co-1' />
|
||||
|
||||
derivation { <co id='ex-hello-nix-co-2' />
|
||||
name = "hello-2.1.1"; <co id='ex-hello-nix-co-3' />
|
||||
system = stdenv.system; <co id='ex-hello-nix-co-4' />
|
||||
builder = ./builder.sh; <co id='ex-hello-nix-co-5' />
|
||||
src = fetchurl { <co id='ex-hello-nix-co-6' />
|
||||
url = ftp://ftp.nluug.nl/pub/gnu/hello/hello-2.1.1.tar.gz;
|
||||
md5 = "70c9ccf9fac07f762c24f2df2290784d";
|
||||
};
|
||||
stdenv = stdenv; <co id='ex-hello-nix-co-7' />
|
||||
perl = perl;
|
||||
}
|
||||
</programlisting>
|
||||
</example>
|
||||
|
||||
<para>
|
||||
A simple Nix expression is shown in <xref linkend='ex-hello-nix' />. It
|
||||
describes how to the build the <ulink
|
||||
url='http://www.gnu.org/directory/GNU/hello.html'>GNU Hello
|
||||
package</ulink>. This package has several dependencies. First, it
|
||||
requires a number of other packages, such as a C compiler, standard
|
||||
Unix shell tools, and Perl. Rather than have this Nix expression refer
|
||||
to and use specific versions of these packages, it should be generic;
|
||||
that is, it should be a <emphasis>function</emphasis> that takes the
|
||||
required packages as inputs and yield a build of the GNU Hello package
|
||||
as a result. This Nix expression defines a function with three
|
||||
arguments <xref linkend='ex-hello-nix-co-1' />, namely:
|
||||
<orderedlist>
|
||||
<listitem><para><varname>stdenv</varname>, which should be a
|
||||
<emphasis>standard environment package</emphasis>. The standard
|
||||
environment is a set of tools and other components that would be
|
||||
expected in a fairly minimal Unix-like environment: a C compiler
|
||||
and linker, Unix shell tools, and so on.</para>
|
||||
</listitem>
|
||||
<listitem><para><varname>fetchurl</varname>, which should be a
|
||||
function that given parameters <varname>url</varname> and
|
||||
<varname>md5</varname>, will fetch a file from the specified
|
||||
location and check that this file has the given MD5 hash code.
|
||||
The hash is required because build operations must be
|
||||
<emphasis>pure</emphasis>: given the same inputs they should
|
||||
always yield the same output. Since network resources can change
|
||||
at any time, we must in some way guarantee what the result will
|
||||
be.</para>
|
||||
</listitem>
|
||||
<listitem><para><varname>perl</varname>, which should be a Perl
|
||||
interpreter.</para>
|
||||
</listitem>
|
||||
</orderedlist>
|
||||
</para>
|
||||
|
||||
<para>
|
||||
The remainder of the file is the body of the function, which happens to
|
||||
be a <emphasis>derivation</emphasis> <xref
|
||||
linkend='ex-hello-nix-co-2' />, which is the built-in function
|
||||
<varname>derivation</varname> applied to a set of attributes that
|
||||
encode all the necessary information for building the GNU Hello
|
||||
package.
|
||||
</para>
|
||||
|
||||
<example>
|
||||
<title>Build script (<filename>builder.sh</filename>) for GNU
|
||||
Hello</title>
|
||||
<programlisting>
|
||||
#! /bin/sh
|
||||
|
||||
buildinputs="$perl"
|
||||
. $stdenv/setup || exit 1
|
||||
|
||||
tar xvfz $src || exit 1
|
||||
cd hello-* || exit 1
|
||||
./configure --prefix=$out || exit 1
|
||||
make || exit 1
|
||||
make install || exit 1
|
||||
</programlisting>
|
||||
</example>
|
||||
|
||||
</sect2>
|
||||
|
||||
<sect2>
|
||||
<title>A more complex Nix expression</title>
|
||||
|
||||
<example id='ex-svn-nix'>
|
||||
<title>Nix expression for Subversion</title>
|
||||
<programlisting>
|
||||
{ localServer ? false <co id='ex-svn-nix-co-1' />
|
||||
, httpServer ? false
|
||||
, sslSupport ? false
|
||||
, swigBindings ? false
|
||||
, stdenv, fetchurl
|
||||
, openssl ? null, httpd ? null, db4 ? null, expat, swig ? null
|
||||
}:
|
||||
|
||||
assert !isNull expat; <co id='ex-svn-nix-co-2' />
|
||||
assert localServer -> !isNull db4;
|
||||
assert httpServer -> !isNull httpd && httpd.expat == expat; <co id='ex-svn-nix-co-3' />
|
||||
assert sslSupport -> !isNull openssl && (httpServer -> httpd.openssl == openssl);
|
||||
assert swigBindings -> !isNull swig;
|
||||
|
||||
derivation {
|
||||
name = "subversion-0.32.1";
|
||||
system = stdenv.system;
|
||||
|
||||
builder = ./builder.sh;
|
||||
src = fetchurl {
|
||||
url = http://svn.collab.net/tarballs/subversion-0.32.1.tar.gz;
|
||||
md5 = "b06717a8ef50db4b5c4d380af00bd901";
|
||||
};
|
||||
|
||||
localServer = localServer;
|
||||
httpServer = httpServer;
|
||||
sslSupport = sslSupport;
|
||||
swigBindings = swigBindings;
|
||||
|
||||
stdenv = stdenv;
|
||||
openssl = if sslSupport then openssl else null; <co id='ex-svn-nix-co-4' />
|
||||
httpd = if httpServer then httpd else null;
|
||||
expat = expat;
|
||||
db4 = if localServer then db4 else null;
|
||||
swig = if swigBindings then swig else null;
|
||||
}
|
||||
</programlisting>
|
||||
</example>
|
||||
|
||||
<para>
|
||||
This example shows several features. Default parameters <xref
|
||||
linkend='ex-svn-nix-co-1'/> can be used to simplify call sites: if an
|
||||
argument that has a default is omitted, its default value is used.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
You can use <emphasis>assertions</emphasis> to test whether arguments
|
||||
satisfy certain constraints. The simple assertion <xref
|
||||
linkend='ex-svn-nix-co-2'/> tests whether the
|
||||
<varname>expat</varname> argument is not a null value. The more
|
||||
complex assertion <xref linkend='ex-svn-nix-co-3'/> says that if
|
||||
Subversion is built with Apache support, then <varname>httpd</varname>
|
||||
(the Apache package) must not be null and it must have been built using
|
||||
the same instance of the <varname>expat</varname> library as was passed
|
||||
to the Subversion expression. This is since the Subversion code is
|
||||
dynamically linked against the Apache code and they both use Expat,
|
||||
they must be linked against the same instance—otherwise a
|
||||
conflict might occur.
|
||||
</para>
|
||||
|
||||
</sect2>
|
||||
|
||||
</sect1>
|
||||
|
||||
|
||||
|
||||
</chapter>
|
||||
|
||||
<!--
|
||||
|
|
Loading…
Reference in a new issue