Perl
Kang-min Liu
@gugod

.meta
• twitter.com/gugod
• Perl / Javascript / Ruby programmer
• CPAN Author for ~100 distributions
• perlbrew

perlbrew

perlbrew
• A tool to install tons of perls
• switch between them
• build with customized options
(-D -A -U)
• build from tarball or git

Usage
perlbrew install perl-5.12.2
perlbrew install perl-5.13.5
* Internet connection is required

Usage
perlbrew install perl-5.10.1
perlbrew install perl-5.8.8
* Internet connection is required

Usage
# git checkout
cd ~/src/perl
perlbrew install .
* Internet connection is not required

Usage
perlbrew installed

> perlbrew installed
perl-5.10.0
perl-5.10.1
perl-5.11.1
perl-5.11.5
perl-5.12.0
perl-5.12.0-RC0
perl-5.12.0-RC3
perl-5.12.1
perl-5.12.2(*)
perl-5.13.0
perl-5.13.2
perl-5.13.4
perl-v5.11.5-15-gd3b0eb1
/Users/gugod/perl5/perlbrew/bin/perl
/Users/gugod/perl5/perlbrew/perls/current/
bin/perl
/usr/bin/perl

Usage
perlbrew switch perl-5.12.2
# Disable perlbrew
perlbrew off

Installation
curl −LO http://xrl.us/perlbrew
chmod +x perlbrew
./perlbrew install

Installation
new
curl -L http://xrl.us/perlbrewinstall | bash

Installation
cpan -i App::perlbrew
* Not recommended

Properties
• does not require sudo
• perl installation are isolated
• site_lib, bin, lib
• install a new version ≠ upgrade
• @INC does not include old site_lib

Benefits
• Easier-to-clean perl environments
• Nuke the whole thing to clean the
mess
• Old @INC does not accumulate with
old perls

Benefits
• per-app isolated perl environments
setup.
• avoid, in advance, any possible
incompatible issues with other
apps.
• know your site_libs
• ‘sudo cpan’ is no more.

Why?
• Don’t mess up vendor perl too
much.
• Learn new stuffs in the dev version
of perl.
• keep up with the fashion

Why?
• Test modules or apps
• ... with newer perl
• ... with older perl

Why?
• Test perl itself
• Threaded perl
• 64bit perl
• performance
• smokebrew

Why?
• Play dark magic kitchen fire
• Devel::Declare, B::*, XS
• Better with a perl built with
DEBUGING

development
• github.com/gugod/App-perlbrew
• so many pull requests
• 20 contributors
• send me pull requests any time!

development
• better bash integration /
experiments
• easy site_lib management (clone /
bundle / nuke)
• Steal some goodies from
Devel::PPPort

←

← perlbrew
• /usr/local/bin/perl
/opt/local/bin/perl
/home/gugod/local/bin/perl
• site_lib is preserved after upgrade

← perlbrew
• perl is so backward compatible
• Ideal for developing and production
• keep upgrading perl is generally OK

← perlbrew
• Upgrading CPAN modules isn’t
necessarily OK.
• Errors happens at runtime, when it’s
not binary-compatible.
• Developers must correctly specify
module dependencies.

← perlbrew
• In CPAN Distribution you do that in
Makefile.PL / META.yml
• Same tool for App

Simple is Hard
• support for legacy code and
decisions.
• perl, cpan
• cpanm, perlbrew: new tools for the
current fashion

Thoughts
perlbrew « cpanm, rvm

Thoughts
• Standalone program
• embed non-core modules
• very easy distribution
• runs a tiny bit faster

Thoughts
• « rvm
• bash programming master-piece
• developer-friendly experiences
• production server

Further Thoughts
• Test::Continuous
• perlbrew
• local::lib
• App::local::lib::helper
• cpanm
• cpan-outdated
• cpansearch

rapidly improves something
a little bit better

rapidly improves something
a little bit better ❤

Hates

Hates
• CPAN dependency list for
$framework is too long
• CPAN $modules takes too long to
install / tests takes very long time
to finish
• $software is too fat (eats too much
memory space) and slow

Less Hateful
• bundle cpan dists with your
distribution
• PAR / Shipwright / %INC hack
• Avoid long dependency list

Less Hateful
• smaller, single-purpose
• less memory consumption
• less sub-commands to be
memorized
• less memory consumption in your
brain
• easier to maintain / be faster

cpan install can run 90% faster...

By skiping all tests,
cpan install can run 90% faster...

Less Hateful
• To skip for tests safely, consult
cpantester.org first
• A cpan/cpanm plugin shall be
written to automates that.

Less Hateful
• Solving long dependency list
problem is a no-op
• if cpan installation is super fast
• like < 1 second / module

Fast fists cannot be broken

side projects

cpan-sets
• cpan-sets: local::lib switcher wrote in
• « rvm gemset, bundler
• App::local::lib::helper
• experimental project
• per-app bundle

cpanfile
# Install with: cpanm < cpanfile
http://github.com/bestpractical/jifty-dbi/tarball/master
http://github.com/bestpractical/jifty/tarball/master
http://github.com/bestpractical/jifty-plugin-openid
B::Hooks::EndOfScope
DateTime
Digest::SHA1
Email::Address
Exporter::Lite
HTML::Entities
JiftyX::Markapl
JiftyX::ModelHelpers
Markapl
Regexp::Common
Regexp::Common::Email::Address
String::BufferStack
Sub::Install
Text::Markdown::Discount
Text::MultiMarkdown
UNIVERSAL::require
common::sense

perlrocks
• rubygems counter-part.
• multi-version module install
• use perlrocks;
# perl5 syntax of ‘use’
use Foo-1.3;
• site_lib/rocks/Foo-1.3/lib/Foo.pm
• Installation tool (rock)

side projects
• github.com/gugod/App-perlbrew
• github.com/gugod/cpan-sets
• github.com/gugod/perlrocks

Conclusion
• github social coding actually works!
• Easy distributing is important.
• Simple is hard.
• Fast is better then slow.

∞
• Good + Simple + Easy toolkit
• Keep new-comers by not frustrating
them
• Grow the community

Thank You