Cookbook(3)

NAME

       Module::Build - Build and install Perl modules

SYNOPSIS

       Standard process for building & installing modules:

         perl Build.PL
         ./Build
         ./Build test
         ./Build install

       Or, if you're on a platform (like DOS or Windows) that doesn't require
       the "./" notation, you can do this:

         perl Build.PL
         Build
         Build test
         Build install

DESCRIPTION

       "Module::Build" is a system for building, testing, and installing Perl
       modules.  It is meant to be an alternative to "ExtUtils::MakeMaker".
       Developers may alter the behavior of the module through subclassing in
       a much more straightforward way than with "MakeMaker".  It also does
       not require a "make" on your system - most of the "Module::Build" code
       is pure-perl and written in a very cross-platform way.  In fact, you
       don't even need a shell, so even platforms like MacOS (traditional) can
       use it fairly easily.  Its only prerequisites are modules that are
       included with perl 5.6.0, and it works fine on perl 5.005 if you can
       install a few additional modules.

       See "MOTIVATIONS" for more comparisons between "ExtUtils::MakeMaker"
       and "Module::Build".

       To install "Module::Build", and any other module that uses "Mod-
       ule::Build" for its installation process, do the following:

         perl Build.PL       # 'Build.PL' script creates the 'Build' script
         ./Build             # Need ./ to ensure we're using this "Build" script
         ./Build test        # and not another one that happens to be in the PATH
         ./Build install

       This illustrates initial configuration and the running of three
       'actions'.  In this case the actions run are 'build' (the default
       action), 'test', and 'install'.  Other actions defined so far include:

         build                          install
         clean                          manifest
         code                           manpages
         config_data                    ppd
         diff                           ppmdist
         dist                           prereq_report
         distcheck                      pure_install
         distclean                      realclean
         distdir                        skipcheck
         distmeta                       test
         distsign                       testcover
         disttest                       testdb
         docs                           testpod
         fakeinstall                    testpodcoverage
         help                           versioninstall
         html

       You can run the 'help' action for a complete list of actions.

GUIDE TO DOCUMENTATION

       The documentation for "Module::Build" is broken up into three sections:

       General Usage (Module::Build)
           This is the document you are currently reading. It describes basic
           usage and background information.  Its main purpose is to assist
           the user who wants to learn how to invoke and control "Mod-
           ule::Build" scripts at the command line.

       Authoring Reference (Module::Build::Authoring)
           This document describes the structure and organization of "Mod-
           ule::Build", and the relevant concepts needed by authors who are
           writing Build.PL scripts for a distribution or controlling "Mod-
           ule::Build" processes programmatically.

       API Reference (Module::Build::API)
           This is a reference to the "Module::Build" API.

       Cookbook (Module::Build::Cookbook)
           This document demonstrates how to accomplish many common tasks.  It
           covers general command line usage and authoring of Build.PL
           scripts.  Includes working examples.

ACTIONS

       There are some general principles at work here.  First, each task when
       building a module is called an "action".  These actions are listed
       above; they correspond to the building, testing, installing, packaging,
       etc., tasks.

       Second, arguments are processed in a very systematic way.  Arguments
       are always key=value pairs.  They may be specified at "perl Build.PL"
       time (i.e. "perl Build.PL destdir=/my/secret/place"), in which case
       their values last for the lifetime of the "Build" script.  They may
       also be specified when executing a particular action (i.e.  "Build test
       verbose=1"), in which case their values last only for the lifetime of
       that command.  Per-action command line parameters take precedence over
       parameters specified at "perl Build.PL" time.

       The build process also relies heavily on the "Config.pm" module, and
       all the key=value pairs in "Config.pm" are available in

       "$self->{config}".  If the user wishes to override any of the values in
       "Config.pm", she may specify them like so:

         perl Build.PL --config cc=gcc --config ld=gcc

       The following build actions are provided by default.

       build
           [version 0.01]

           If you run the "Build" script without any arguments, it runs the
           "build" action, which in turn runs the "code" and "docs" actions.

           This is analogous to the MakeMaker 'make all' target.

       clean
           [version 0.01]

           This action will clean up any files that the build process may have
           created, including the "blib/" directory (but not including the
           "_build/" directory and the "Build" script itself).

       code
           [version 0.20]

           This action builds your codebase.

           By default it just creates a "blib/" directory and copies any ".pm"
           and ".pod" files from your "lib/" directory into the "blib/" direc-
           tory.  It also compiles any ".xs" files from "lib/" and places them
           in "blib/".  Of course, you need a working C compiler (probably the
           same one that built perl itself) for the compilation to work prop-
           erly.

           The "code" action also runs any ".PL" files in your lib/ directory.
           Typically these create other files, named the same but without the
           ".PL" ending.  For example, a file lib/Foo/Bar.pm.PL could create
           the file lib/Foo/Bar.pm.  The ".PL" files are processed first, so
           any ".pm" files (or other kinds that we deal with) will get copied
           correctly.

       config_data
           [version 0.26]

           ...

       diff
           [version 0.14]

           This action will compare the files about to be installed with their
           installed counterparts.  For .pm and .pod files, a diff will be
           shown (this currently requires a 'diff' program to be in your
           PATH).  For other files like compiled binary files, we simply
           report whether they differ.

           A "flags" parameter may be passed to the action, which will be
           passed to the 'diff' program.  Consult your 'diff' documentation
           for the parameters it will accept - a good one is "-u":

             ./Build diff flags=-u

       dist
           [version 0.02]

           This action is helpful for module authors who want to package up
           their module for source distribution through a medium like CPAN.
           It will create a tarball of the files listed in MANIFEST and com-
           press the tarball using GZIP compression.

           By default, this action will use the external "tar" and "gzip" exe-
           cutables on Unix-like platforms, and the "Archive::Tar" module
           elsewhere.  However, you can force it to use whatever executable
           you want by supplying an explicit "tar" (and optional "gzip")
           parameter:

             ./Build dist --tar C:\path\to\tar.exe --gzip C:\path\to\zip.exe

       distcheck
           [version 0.05]

           Reports which files are in the build directory but not in the MANI-
           FEST file, and vice versa.  (See manifest for details.)

       distclean
           [version 0.05]

           Performs the 'realclean' action and then the 'distcheck' action.

       distdir
           [version 0.05]

           Creates a "distribution directory" named "$dist_name-$dist_version"
           (if that directory already exists, it will be removed first), then
           copies all the files listed in the MANIFEST file to that directory.
           This directory is what the distribution tarball is created from.

       distmeta
           [version 0.21]

           Creates the META.yml file that describes the distribution.

           META.yml is a file containing various bits of "metadata" about the
           distribution.  The metadata includes the distribution name, ver-
           sion, abstract, prerequisites, license, and various other data
           about the distribution.  This file is created as META.yml in YAML
           format.  It is recommended that the "YAML" module be installed to
           create it.  If the "YAML" module is not installed, an internal mod-
           ule supplied with Module::Build will be used to write the META.yml
           file, and this will most likely be fine.

           META.yml file must also be listed in MANIFEST - if it's not, a
           warning will be issued.

           The current version of the META.yml specification can be found at
           <http://module-build.sourceforge.net/META-spec-v1.2.html>

       distsign
           [version 0.16]

           Uses "Module::Signature" to create a SIGNATURE file for your dis-
           tribution, and adds the SIGNATURE file to the distribution's MANI-
           FEST.

       disttest
           [version 0.05]

           Performs the 'distdir' action, then switches into that directory
           and runs a "perl Build.PL", followed by the 'build' and 'test'
           actions in that directory.

       docs
           [version 0.20]

           This will generate documentation (e.g. Unix man pages and html doc-
           uments) for any installable items under blib/ that contain POD.  If
           there are no "bindoc" or "libdoc" installation targets defined (as
           will be the case on systems that don't support Unix manpages) no
           action is taken for manpages.  If there are no "binhtml" or "lib-
           html" installation targets defined no action is taken for html doc-
           uments.

       fakeinstall
           [version 0.02]

           This is just like the "install" action, but it won't actually do
           anything, it will just report what it would have done if you had
           actually run the "install" action.

       help
           [version 0.03]

           This action will simply print out a message that is meant to help
           you use the build process.  It will show you a list of available
           build actions too.

           With an optional argument specifying an action name (e.g. "Build
           help test"), the 'help' action will show you any POD documentation
           it can find for that action.

       html
           [version 0.26]

           This will generate HTML documentation for any binary or library
           files under blib/ that contain POD.  The HTML documentation will
           only be installed if the install paths can be determined from val-
           ues in "Config.pm".  You can also supply or override install paths
           on the command line by specifying "install_path" values for the
           "binhtml" and/or "libhtml" installation targets.

       install
           [version 0.01]

           This action will use "ExtUtils::Install" to install the files from
           "blib/" into the system.  See "INSTALL PATHS" for details about how
           Module::Build determines where to install things, and how to influ-
           ence this process.

           If you want the installation process to look around in @INC for
           other versions of the stuff you're installing and try to delete it,
           you can use the "uninst" parameter, which tells "ExtUtils::Install"
           to do so:

             ./Build install uninst=1

           This can be a good idea, as it helps prevent multiple versions of a
           module from being present on your system, which can be a confusing
           situation indeed.

       manifest
           [version 0.05]

           This is an action intended for use by module authors, not people
           installing modules.  It will bring the MANIFEST up to date with the
           files currently present in the distribution.  You may use a MANI-
           FEST.SKIP file to exclude certain files or directories from inclu-
           sion in the MANIFEST.  MANIFEST.SKIP should contain a bunch of reg-
           ular expressions, one per line.  If a file in the distribution
           directory matches any of the regular expressions, it won't be
           included in the MANIFEST.

           The following is a reasonable MANIFEST.SKIP starting point, you can
           add your own stuff to it:

             ^_build
             ^Build$
             ^blib
             ~$
             \.bak$
             ^MANIFEST\.SKIP$
             CVS

           See the distcheck and skipcheck actions if you want to find out
           what the "manifest" action would do, without actually doing any-
           thing.

       manpages
           [version 0.28]

           This will generate man pages for any binary or library files under
           blib/ that contain POD.  The man pages will only be installed if
           the install paths can be determined from values in "Config.pm".
           You can also supply or override install paths by specifying there
           values on the command line with the "bindoc" and "libdoc" installa-
           tion targets.

       ppd [version 0.20]

           Build a PPD file for your distribution.

           This action takes an optional argument "codebase" which is used in
           the generated ppd file to specify the (usually relative) URL of the
           distribution.  By default, this value is the distribution name
           without any path information.

           Example:

             ./Build ppd --codebase "MSWin32-x86-multi-thread/Module-Build-0.21.tar.gz"

       ppmdist
           [version 0.23]

           Generates a PPM binary distribution and a PPD description file.
           This action also invokes the 'ppd' action, so it can accept the
           same "codebase" argument described under that action.

           This uses the same mechanism as the "dist" action to tar & zip its
           output, so you can supply "tar" and/or "gzip" parameters to affect
           the result.

       prereq_report
           [version 0.28]

           This action prints out a list of all prerequisites, the versions
           required, and the versions actually installed.  This can be useful
           for reviewing the configuration of your system prior to a build, or
           when compiling data to send for a bug report.

       pure_install
           [version 0.28]

           This action is identical to the "install" action.  In the future,
           though, if "install" starts writing to the file file $(INSTALLARCH-
           LIB)/perllocal.pod, "pure_install" won't, and that will be the only
           difference between them.

       realclean
           [version 0.01]

           This action is just like the "clean" action, but also removes the
           "_build" directory and the "Build" script.  If you run the "real-
           clean" action, you are essentially starting over, so you will have
           to re-create the "Build" script again.

       skipcheck
           [version 0.05]

           Reports which files are skipped due to the entries in the MANI-
           FEST.SKIP file (See manifest for details)

       test
           [version 0.01]

           This will use "Test::Harness" to run any regression tests and
           report their results.  Tests can be defined in the standard places:
           a file called "test.pl" in the top-level directory, or several
           files ending with ".t" in a "t/" directory.

           If you want tests to be 'verbose', i.e. show details of test execu-
           tion rather than just summary information, pass the argument "ver-
           bose=1".

           If you want to run tests under the perl debugger, pass the argument
           "debugger=1".

           In addition, if a file called "visual.pl" exists in the top-level
           directory, this file will be executed as a Perl script and its out-
           put will be shown to the user.  This is a good place to put speed
           tests or other tests that don't use the "Test::Harness" format for
           output.

           To override the choice of tests to run, you may pass a "test_files"
           argument whose value is a whitespace-separated list of test scripts
           to run.  This is especially useful in development, when you only
           want to run a single test to see whether you've squashed a certain
           bug yet:

             ./Build test --test_files t/something_failing.t

           You may also pass several "test_files" arguments separately:

             ./Build test --test_files t/one.t --test_files t/two.t

           or use a "glob()"-style pattern:

             ./Build test --test_files 't/01-*.t'

       testcover
           [version 0.26]

           Runs the "test" action using "Devel::Cover", generating a code-cov-
           erage report showing which parts of the code were actually exer-
           cised during the tests.

           To pass options to "Devel::Cover", set the $DEVEL_COVER_OPTIONS
           environment variable:

             DEVEL_COVER_OPTIONS=-ignore,Build ./Build testcover

       testdb
           [version 0.05]

           This is a synonym for the 'test' action with the "debugger=1" argu-
           ment.

       testpod
           [version 0.25]

           This checks all the files described in the "docs" action and pro-
           duces "Test::Harness"-style output.  If you are a module author,
           this is useful to run before creating a new release.

       testpodcoverage
           [version 0.28]

           This checks the pod coverage of the distribution and produces
           "Test::Harness"-style output. If you are a module author, this is
           useful to run before creating a new release.

       versioninstall
           [version 0.16]

           ** Note: since "only.pm" is so new, and since we just recently
           added support for it here too, this feature is to be considered
           experimental. **

           If you have the "only.pm" module installed on your system, you can
           use this action to install a module into the version-specific
           library trees.  This means that you can have several versions of
           the same module installed and "use" a specific one like this:

             use only MyModule => 0.55;

           To override the default installation libraries in "only::config",
           specify the "versionlib" parameter when you run the "Build.PL"
           script:

             perl Build.PL --versionlib /my/version/place/

           To override which version the module is installed as, specify the
           "versionlib" parameter when you run the "Build.PL" script:

             perl Build.PL --version 0.50

           See the "only.pm" documentation for more information on version-
           specific installs.

OPTIONS

       Command Line Options

       The following options can be used during any invocation of "Build.PL"
       or the Build script, during any action.  For information on other
       options specific to an action, see the documentation for the respective
       action.

       NOTE: There is some preliminary support for options to use the more
       familiar long option style.  Most options can be preceded with the "--"
       long option prefix, and the underscores changed to dashes (e.g.
       --use-rcfile).  Additionally, the argument to boolean options is
       optional, and boolean options can be negated by prefixing them with
       'no' or 'no-' (e.g. --noverbose or --no-verbose).

       quiet
           Suppress informative messages on output.

       use_rcfile
           Load the ~/.modulebuildrc option file.  This option can be set to
           false to prevent the custom resource file from being loaded.

       verbose
           Display extra information about the Build on output.

       Default Options File (.modulebuildrc)

       [version 0.28]

       When Module::Build starts up, it will look first for a file,
       $ENV{HOME}/.modulebuildrc.  If it's not found there, it will look in
       the the .modulebuildrc file in the directories referred to by the envi-
       ronment variables "HOMEDRIVE" + "HOMEDIR", "USERPROFILE", "APPDATA",
       "WINDIR", "SYS$LOGIN".  If the file exists, the options specified there
       will be used as defaults, as if they were typed on the command line.
       The defaults can be overridden by specifying new values on the command
       line.

       The action name must come at the beginning of the line, followed by any
       amount of whitespace and then the options.  Options are given the same
       as they would be on the command line.  They can be separated by any
       amount of whitespace, including newlines, as long there is whitespace
       at the beginning of each continued line.  Anything following a hash
       mark ("#") is considered a comment, and is stripped before parsing.  If
       more than one line begins with the same action name, those lines are
       merged into one set of options.

       Besides the regular actions, there are two special pseudo-actions: the
       key "*" (asterisk) denotes any global options that should be applied to
       all actions, and the key 'Build_PL' specifies options to be applied
       when you invoke "perl Build.PL".

         *        verbose=1   # global options
         diff     flags=-u
         install  --install_base /home/ken
                  --install_path html=/home/ken/docs/html

       If you wish to locate your resource file in a different location, you
       can set the environment variable 'MODULEBUILDRC' to the complete abso-
       lute path of the file containing your options.

INSTALL PATHS

[version 0.19]

When you invoke Module::Build's "build" action, it needs to figure out
where to install things. The nutshell version of how this works is
that default installation locations are determined from Config.pm, and
they may be overridden by using the "install_path" parameter. An
"install_base" parameter lets you specify an alternative installation
root like /home/foo, and a "destdir" lets you specify a temporary
installation directory like /tmp/install in case you want to create
bundled-up installable packages.

Natively, Module::Build provides default installation locations for the
following types of installable items:

lib Usually pure-Perl module files ending in .pm.

arch
"Architecture-dependent" module files, usually produced by compil-
ing XS, Inline, or similar code.

script
Programs written in pure Perl. In order to improve reuse, try to
make these as small as possible - put the code into modules when-
ever possible.

bin "Architecture-dependent" executable programs, i.e. compiled C code
or something. Pretty rare to see this in a perl distribution, but
it happens.

bindoc
Documentation for the stuff in "script" and "bin". Usually gener-
ated from the POD in those files. Under Unix, these are manual
pages belonging to the 'man1' category.

libdoc
Documentation for the stuff in "lib" and "arch". This is usually
generated from the POD in .pm files. Under Unix, these are manual
pages belonging to the 'man3' category.

binhtml
This is the same as "bindoc" above, but applies to html documents.

libhtml
This is the same as "bindoc" above, but applies to html documents.

Four other parameters let you control various aspects of how installa-
tion paths are determined:

installdirs
The default destinations for these installable things come from
entries in your system's "Config.pm". You can select from three
different sets of default locations by setting the "installdirs"
parameter as follows:

'installdirs' set to:
core site vendor

uses the following defaults from Config.pm:

lib => installprivlib installsitelib installvendorlib
arch => installarchlib installsitearch installvendorarch
script => installscript installsitebin installvendorbin
bin => installbin installsitebin installvendorbin
bindoc => installman1dir installsiteman1dir installvendorman1dir
libdoc => installman3dir installsiteman3dir installvendorman3dir
binhtml => installhtml1dir installsitehtml1dir installvendorhtml1dir [*]
libhtml => installhtml3dir installsitehtml3dir installvendorhtml3dir [*]

* Under some OS (eg. MSWin32) the destination for html documents is
determined by the C<Config.pm> entry C<installhtmldir>.

The default value of "installdirs" is "site". If you're creating
vendor distributions of module packages, you may want to do some-
thing like this:

perl Build.PL --installdirs vendor

./Build install --installdirs vendor

If you're installing an updated version of a module that was
included with perl itself (i.e. a "core module"), then you may set
"installdirs" to "core" to overwrite the module in its present
location.

(Note that the 'script' line is different from MakeMaker - unfortu-
nately there's no such thing as "installsitescript" or "installven-
dorscript" entry in "Config.pm", so we use the "installsitebin" and
"installvendorbin" entries to at least get the general location
right. In the future, if "Config.pm" adds some more appropriate
entries, we'll start using those.)

install_path
Once the defaults have been set, you can override them.

On the command line, that would look like this:

perl Build.PL --install_path lib=/foo/lib --install_path arch=/foo/lib/arch

or this:

./Build install --install_path lib=/foo/lib --install_path arch=/foo/lib/arch

install_base
You can also set the whole bunch of installation paths by supplying
the "install_base" parameter to point to a directory on your sys-
tem. For instance, if you set "install_base" to "/home/ken" on a
Linux system, you'll install as follows:

lib => /home/ken/lib/perl5
arch => /home/ken/lib/perl5/i386-linux
script => /home/ken/bin
bin => /home/ken/bin
bindoc => /home/ken/man/man1
libdoc => /home/ken/man/man3
binhtml => /home/ken/html
libhtml => /home/ken/html

Note that this is different from how MakeMaker's "PREFIX" parameter
works. See "Why PREFIX is not recommended" for more details.
"install_base" just gives you a default layout under the directory
you specify, which may have little to do with the
"installdirs=site" layout.

The exact layout under the directory you specify may vary by system
- we try to do the "sensible" thing on each platform.

destdir
If you want to install everything into a temporary directory first
(for instance, if you want to create a directory tree that a pack-
age manager like "rpm" or "dpkg" could create a package from), you
can use the "destdir" parameter:

perl Build.PL --destdir /tmp/foo

./Build install --destdir /tmp/foo

This will effectively install to "/tmp/foo/$sitelib",
"/tmp/foo/$sitearch", and the like, except that it will use
"File::Spec" to make the pathnames work correctly on whatever plat-
form you're installing on.

prefix
Provided for compatibility with ExtUtils::MakeMaker's PREFIX argu-
ment. "prefix" should be used when you wish Module::Build to
install your modules, documentation and scripts in the same place
ExtUtils::MakeMaker does.

The following are equivalent.

perl Build.PL --prefix /tmp/foo
perl Makefile.PL PREFIX=/tmp/foo

Because of the very complex nature of the prefixification logic,
the behavior of PREFIX in MakeMaker has changed subtly over time.
Module::Build's --prefix logic is equivalent to the PREFIX logic
found in ExtUtils::MakeMaker 6.30.

If you do not need to retain compatibility with ExtUtils::MakeMaker
or are starting a fresh Perl installation we recommand you use
"install_base" instead (and "INSTALL_BASE" in ExtUtils::MakeMaker).
See "Instaling in the same location as ExtUtils::MakeMaker" in Mod-
ule::Build::Cookbook for further information.

MOTIVATIONS

       There are several reasons I wanted to start over, and not just fix what
       I didn't like about MakeMaker:

       o   I don't like the core idea of MakeMaker, namely that "make" should
           be involved in the build process.  Here are my reasons:

           +   When a person is installing a Perl module, what can you assume
               about their environment?  Can you assume they have "make"?  No,
               but you can assume they have some version of Perl.

           +   When a person is writing a Perl module for intended distribu-
               tion, can you assume that they know how to build a Makefile, so
               they can customize their build process?  No, but you can assume
               they know Perl, and could customize that way.

           For years, these things have been a barrier to people getting the
           build/install process to do what they want.

       o   There are several architectural decisions in MakeMaker that make it
           very difficult to customize its behavior.  For instance, when using
           MakeMaker you do "use ExtUtils::MakeMaker", but the object created
           in "WriteMakefile()" is actually blessed into a package name that's
           created on the fly, so you can't simply subclass "ExtUtils::Make-
           Maker".  There is a workaround "MY" package that lets you override
           certain MakeMaker methods, but only certain explicitly preselected
           (by MakeMaker) methods can be overridden.  Also, the method of cus-
           tomization is very crude: you have to modify a string containing
           the Makefile text for the particular target.  Since these strings
           aren't documented, and can't be documented (they take on different
           values depending on the platform, version of perl, version of Make-
           Maker, etc.), you have no guarantee that your modifications will
           work on someone else's machine or after an upgrade of MakeMaker or
           perl.

       o   It is risky to make major changes to MakeMaker, since it does so
           many things, is so important, and generally works.  "Module::Build"
           is an entirely separate package so that I can work on it all I
           want, without worrying about backward compatibility.

       o   Finally, Perl is said to be a language for system administration.
           Could it really be the case that Perl isn't up to the task of
           building and installing software?  Even if that software is a bunch
           of stupid little ".pm" files that just need to be copied from one
           place to another?  My sense was that we could design a system to
           accomplish this in a flexible, extensible, and friendly manner.  Or
           die trying.

TO DO

       The current method of relying on time stamps to determine whether a
       derived file is out of date isn't likely to scale well, since it
       requires tracing all dependencies backward, it runs into problems on
       NFS, and it's just generally flimsy.  It would be better to use an MD5
       signature or the like, if available.  See "cons" for an example.

        - append to perllocal.pod
        - add a 'plugin' functionality

AUTHOR

       Ken Williams <kwilliams@cpan.org>

       Development questions, bug reports, and patches should be sent to the
       Module-Build mailing list at <module-build-general@lists.source-
       forge.net>.

       Bug reports are also welcome at
       <http://rt.cpan.org/NoAuth/Bugs.html?Dist=Module-Build>.

       The latest development version is available from the Subversion reposi-
       tory at <https://svn.perl.org/modules/Module-Build/trunk/>

COPYRIGHT

       Copyright (c) 2001-2005 Ken Williams.  All rights reserved.

       This library is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.