NAME
    App::cpanminus - get, unpack, build and install modules from CPAN

SYNOPSIS
        cpanm Module
        cpanm MIYAGAWA/Plack-1.0000.tar.gz
        cpanm ~/mydists/MyCompany-Framework-1.0.tar.gz
        cpanm http://example.com/MyModule-0.1.tar.gz
        cpanm http://github.com/miyagawa/Tatsumaki/tarball/master
        cpanm --interactive Task::Kensho

    Run `cpanm -h' for more options.

DESCRIPTION
    cpanminus is a script to get, unpack, build and install modules from
    CPAN.

    Why? It's dependency free, requires zero configuration, and stands alone
    -- but it's maintainable and extensible with plugins and friendly to
    shell scripting. When running, it requires only 10MB of RAM.

INSTALLATION
    There are Debian packages, RPMs, FreeBSD ports, and packages for other
    operation systems available. If you want to use the package management
    system, search for cpanminus and use the appropriate command to install.
    This makes it easy to install `cpanm' to your system without thinking
    about where to install, and later upgrade.

    If you want to build the latest from source,

        git clone git://github.com/miyagawa/cpanminus.git
        cd cpanminus
        perl Makefile.PL
        make install # or sudo make install if you're non root

    This will install `cpanm' to your bin directory like `/usr/local/bin'
    (unless you configured `INSTALL_BASE' with local::lib), so you might
    need to sudo. Later you can say `cpanm --self-upgrade --sudo' to upgrade
    to the latest version.

    Otherwise,

        cd ~/bin
        wget http://xrl.us/cpanm
        chmod +x cpanm
        # edit shebang if you don't have /usr/bin/env

    just works, but be sure to grab the new version manually when you
    upgrade (`--self-upgrade' might not work).

DEPENDENCIES
    perl 5.8 or later (Actually I believe it works with pre 5.8 too but I
    haven't tested this).

    *   'tar' executable (bsdtar or GNU tar version 1.22 are rcommended) or
        Archive::Tar to unpack files.

    *   C compiler, if you want to build XS modules.

    And optionally:

    *   make, if you want to reliably install MakeMaker based modules

    *   Module::Build (core in 5.10) to install Build.PL based modules

PLUGINS
    WARNING: plugin API is not stable so this feature is turned off by
    default for now. To enable plugins you have to be savvy enough to look
    at the build.log or read the source code to see how :)

    The cpanminus core is a compact and simple 1000 lines of code (with some
    embedded utilities and documents) but can be extended by writing
    plugins. Plugins are flat perl scripts placed inside `~/.cpanm/plugins'.
    You can copy (or symlink, if you're a developer) a plugin file to the
    directory to enable plugins. Delete the file or symlink to disable it.

    See the `plugins/' directory in the git repository
    http://github.com/miyagawa/cpanminus for the list of available and
    sample plugins.

QUESTIONS
  Another CPAN installer?
    OK, the first motivation was this: the CPAN shell runs out of memory (or
    swaps heavily and gets really slow) on Slicehost/linode's most
    affordable plan with only 256MB RAM. Should I pay more to install perl
    modules from CPAN? I don't think so.

  But why a new client?
    First of all, I have no intention to dis CPAN or CPANPLUS developers.
    Don't get me wrong. They're great tools I've used for *literally* years
    (you know how many modules I have on CPAN, right?). I really respect
    their efforts of maintaining the most important tools in the CPAN
    toolchain ecosystem.

    However, for less experienced users (mostly from outside the Perl
    community), or even really experienced Perl developers who know how to
    shoot themselves in their feet, setting up the CPAN toolchain often
    feels like yak shaving, especially when all they want to do is just
    install some modules and start writing code.

    In particular, here are the few issues I've observed:

    *   They ask too many questions and do not provide enough sane defaults.
        A normal user doesn't (and shouldn't have to) know what's the right
        answer for the question `Parameters for the 'perl Build.PL' command?
        []'

    *   They provide very noisy output by default.

    *   They fetches and rebuild their indexes almost every day, and this
        takes time.

    *   ... and they hog 200MB of memory and thrashes/OOMs on my 256MB VPS

    cpanminus is designed to be very quiet (but logs all output to
    `~/.cpanm/build.log') and to pick the sanest possibledefaults without
    asking any questions -- to *just work*.

    Note that most of these problems with existing tools are rare, or are
    just overstated. They might already be fixed, or can be configured to
    work nicer. For instance, the latest CPAN.pm dev release has a much
    better first time configuration experience than ever before.

    I know there's a reason for them to have many options and questions,
    because they're meant to work everywhere for everybody.

    Of course I should have contributed back to CPAN/CPANPLUS instead of
    writing a new client, but CPAN.pm is nearly impossible (for anyone other
    than andk or xdg) to maintain (that's why CPANPLUS was born, right?) and
    CPANPLUS is a huge beast for me to start working on.

  Are you on drugs?
    Yeah, I think my brain has been damaged since I looked at PyPI,
    gemcutter, pip and rip. They're quite nice and I really wanted something
    as nice for CPAN which I love.

  How does this thing work?
    Imagine you don't have CPAN or CPANPLUS. You search for a module on the
    CPAN search site, download a tarball, unpack it and then run `perl
    Makefile.PL' (or `perl Build.PL'). If the module has dependencies you
    probably have to resolve those dependencies by hand before doing so.
    Then you run the unit tests and `make install' (or `./Build install').

    cpanminus automates that.

  Zero-conf? How does this module get/parse/update the CPAN index?
    It queries the CPAN Meta DB site running on Google AppEngine at
    http://cpanmetadb.appspot.com/. The site is updated every hour to
    reflect the latest changes from fast syncing mirrors. The script then
    also falls back to the site http://search.cpan.org/. I've been talking
    to and working with with the QA/toolchain people for building a more
    reliable CPAN DB website.

    Fetched files are unpacked in `~/.cpanm'. You can configure this with
    the `PERL_CPANM_HOME' environment variable.

  Where does this install modules to? Do I need root access?
    It installs to wherever ExtUtils::MakeMaker and Module::Build are
    configured to (via `PERL_MM_OPT' and `MODULEBUILDRC'). So if you're
    using local::lib, then it installs to your local perl5 directory.
    Otherwise it installs to the siteperl directory.

    cpanminus at a boot time checks whether you have configured local::lib,
    or have the permission to install modules to the sitelib directory. If
    neither, it automatically sets up local::lib compatible installation
    path in a `perl5' directory under your home directory. To avoid this,
    run the script as the root user or with `--sudo' option.

    This local::lib automatic integration is still considered alpha and in
    the work -- more bootstrapping is under development. Stay tuned.

  Does this really work?
    I tested installing MojoMojo, Task::Kensho, KiokuDB, Catalyst, Jifty and
    Plack using cpanminus and the installations including dependencies were
    mostly successful. More than *half of CPAN* behaves really nicely and
    appears to work.

    However, there might be some distributions that will miserably fail,
    because of nasty edge cases. Here are some examples:

    *   Packages uploaded to PAUSE in 90s which don't live under the
        standard `authors/id/A/AA' directory hierarchy.

    *   Distributions with a `Makefile.PL' or `Build.PL' that asks you
        questions without using `prompt' function. However cpanminus has a
        mechanism to kill those questions with a timeout, and you can always
        say `--interactive' to make the configuration interactive.

    *   Distributions that do not shipped with `META.yml' file but do
        require some specific version of toolchain for configuration.

    *   Distributions that test a SIGNATURE in the `*.t' unit tests and has
        `MANIFEST.SKIP' file in the distribution at the same time. The
        intent of signature testing is to provide some degree of security,
        but running it in unit tests is too late as it occurs *after*
        running `Makefile.PL'. cpanminus has a `verify_signature' plugin to
        verify the dist before configurations.

    *   Distributions that have a `META.yml' file that is encoded in YAML
        1.1 format using YAML::XS. This will be eventually solved once we
        move to `META.json'.

    cpanminus intends to work for 99.9% of modules on CPAN for 99.9% of
    people. It may not be perfect, but it should just work in most cases.

    If this tool doesn't work for your very rare environment, then I'm
    sorry, but you should use CPAN or CPANPLUS, or build and install modules
    manually.

  That sounds fantastic. Should I switch to this from CPAN(PLUS)?
    If you have CPAN or CPANPLUS working then you may want to keep using
    CPAN or CPANPLUS in the longer term, but I hope this can be a quite
    handy alternative to them for people in other situations. And
    apparently, many people love (at least the idea of) this software :)

COPYRIGHT
    Copyright 2010- Tatsuhiko Miyagawa

    The standalone executable contains the following modules embedded.

    Parse::CPAN::Meta Copyright 2006-2009 Adam Kennedy
    local::lib Copyright 2007-2009 Matt S Trout
    HTTP::Lite Copyright 2000-2002 Roy Hopper, 2009 Adam Kennedy

LICENSE
    Same as Perl.

CREDITS
  CONTRIBUTORS
    Patches and code improvements were contributed by:

    Goro Fuji, Kazuhiro Osawa, Tokuhiro Matsuno, Kenichi Ishigaki, Ian
    Wells, Pedro Melo, Masayoshi Sekimura, Matt S Trout, squeeky, horus and
    Ingy dot Net.

  ACKNOWLEDGEMENTS
    Bug reports, suggestions and feedbacks were sent by, or general
    acknowledgement goes to:

    Jesse Vincent, David Golden, Andreak Koenig, Jos Boumans, Chris
    Williams, Adam Kennedy, Audrey Tang, J. Shirley, Chris Prather, Jesse
    Luehrs, Marcus Ramberg, Shawn M Moore, chocolateboy, Chirs Nehren,
    Jonathan Rockway, Leon Brocard, Simon Elliott, Ricardo Signes, AEvar
    Arnfjord Bjarmason, Eric Wilhelm, Florian Ragwitz and xaicron.

COMMUNITY
    http://github.com/miyagawa/cpanminus - source code repository, issue
    tracker
    irc: - discussions about Perl toolchain. I'm there.

NO WARRANTY
    This software is provided "as-is," without any express or implied
    warranty. In no event shall the author be held liable for any damages
    arising from the use of the software.

SEE ALSO
    CPAN CPANPLUS pip