Ruby Install

Ruby, just like any other language, has a lot of different ways to handle different ruby versions and ruby libraries.

For a quick overview, we have the following:

system ruby - the ruby that your OS uses
RVM - is a tool for installing multiple versions of ruby on a single machine There’s other ways to do this, including using say rbenv instead if you want
bundler - based on your Gemfile, bundler runs bundle install to download and install all your gems. If you want to manually install each gem, you run gem install <gem_name> Bundler is packaged as a gem too
gems - ruby libraries are installed as gems think of these as jars for Java Inside a gem, there’s the ruby code, tests, and a gemspec file (showing dependencies and version) A ruby project defines the gems it needs in a Gemfile
gemset - a gemset in RVM is a set of gems specific to a given context, usually a project rvm gemset list rvm gemset create mygemset to create a new gemset or to be more specific rvm --create --ruby-version ruby-1.9.3@mygemset rvm use 2.1.1@mygemset or rvm use @mygemset

Install Ruby

To install a system level ruby

For Ubuntu

sudo apt-get install ruby`ruby -e 'puts RUBY_VERSION[/\d+\.\d+/]'`-dev
sudo apt-get install ruby-dev

For Mac

brew install ruby

Ruby Version Manager (RVM)

Install RVM

Install RVM here: https://rvm.io/

Install GPG keys:

$gpg2 --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB

Install RVM with default Ruby and Rails in one command

$\curl -sSL https://get.rvm.io | bash -s stable --rails

Go through the rest of the install and you’ll be able to:

RVM Usage

See what ruby versions you have installed

$ rvm list
* ruby-2.3.4 [ x86_64 ]
   ruby-2.3.7 [ x86_64 ]
   ruby-2.4.1 [ x86_64 ]
   ruby-2.4.4 [ x86_64 ]
   ruby-2.5.0 [ x86_64 ]
   ruby-2.6.0 [ x86_64 ]
   ruby-2.6.2 [ x86_64 ]

See the current default version of ruby

$ rvm --default use ruby-X.X.X

To install a specific version of ruby

$ rvm install 2.6.0

To list out all possible installations of ruby, run:

$ rvm list known

# MRI Rubies
[ruby-]1.8.6[-p420]
[ruby-]1.8.7[-head] # security released on head
[ruby-]1.9.1[-p431]
[ruby-]1.9.2[-p330]
[ruby-]1.9.3[-p551]
[ruby-]2.0.0[-p648]
[ruby-]2.1[.10]
[ruby-]2.2[.10]
[ruby-]2.3[.8]
[ruby-]2.4[.5]
[ruby-]2.5[.3]
[ruby-]2.6[.0]
ruby-head

# for forks use: rvm install ruby-head-<name> --url https://github.com/github/ruby.git --branch 2.2

# JRuby
jruby-1.6[.8]
jruby-1.7[.27]
jruby-9.1[.17.0]
jruby[-9.2.5.0]
jruby-head

# Rubinius
rbx-1[.4.3]
rbx-2.3[.0]
rbx-2.4[.1]
rbx-2[.5.8]
rbx-3[.100]
rbx-head

# TruffleRuby
truffleruby[-1.0.0-rc10]

# Opal
opal

# Minimalistic ruby implementation - ISO 30170:2012
mruby-1.0.0
mruby-1.1.0
mruby-1.2.0
mruby-1.3.0
mruby-1[.4.1]
mruby-2[.0.0]
mruby[-head]

# Ruby Enterprise Edition
ree-1.8.6
ree[-1.8.7][-2012.02]

# Topaz
topaz

# MagLev
maglev-1.0.0
maglev-1.1[RC1]
maglev[-1.2Alpha4]
maglev-head

# Mac OS X Snow Leopard Or Newer
macruby-0.10
macruby-0.11
macruby[-0.12]
macruby-nightly
macruby-head

# IronRuby
ironruby[-1.1.3]
ironruby-head

Bundle

Bundler is a tool for dependency management. Bundler makes sure all your dependencies in your Gemfile are available to your application. Bundle is a gem, even though it is used to install gems. Bundle installs all the gems in your Gemfile.lock

gem install bundler
bundle update  # if needed update your bundler; your Gemfile.lock will show `Bundled With` and a version
bundle install  # install the dependencies specified in your Gemfile, creates a `Gemfile.lock` if it does not exist

RubyGems

Gemsets

Before you install your gems, consider using a gemset. It’s like a virtualenv with a specific name to handle your group of gems for your program.

rvm gemset create myproject

Install Gems

Install your gems (i.e. libraries)

sudo apt-get install rubygems

gem env  # will show you where your gem paths are
gem list  # lists out all your gems (like python's `pip freeze`)
gem search [gem_name]
gem install my_gem
gem uninstall my_gem
gem server  # to start up server to show what gems are installed

Example of gem list

$ gem list

*** LOCAL GEMS ***

bundler (2.0.1, default: 1.17.2)
bundler-unload (1.0.2)
byebug (11.0.0)
cmath (default: 1.0.0)
coderay (1.1.2)
concurrent-ruby (1.1.5)
connection_pool (2.2.2)
csv (default: 3.0.4)
date (default: 2.0.0)
sidekiq (5.2.5)
simplecov (0.16.1)
simplecov-html (0.10.2)

Linking to a local gem

gem 'my-gem', '~> 3.5.0', :path => '/Users/william.liu/workspace/my-gem'