Ruby is a dynamic, interpreted, open source programming language with a focus on simplicity and productivity.
For the latest version of Ruby, install the package.
To install IRB, install the package.
To make documentation available through the
ri command-line tool, install and for the documentation itself.
You can then query the docs with:
ri Array.pop etc. (much like man-pages)
RubyGems is a package manager for Ruby modules (called gems), somewhat comparable to what pacman is to Arch Linux. It can be installed with the package, which is a dependency of .
By default in Arch Linux, when running
gem, gems are installed per-user (into
~/.local/share/gem/ruby/), instead of system-wide (into
/usr/lib/ruby/gems/). This is considered the best way to manage gems on Arch, because otherwise they might interfere with gems installed by Pacman.
export GEM_HOME="$(ruby -e 'puts Gem.user_dir')" export PATH="$PATH:$GEM_HOME/bin"
This is required for executable gems to work without typing out the full location, although libraries will work without having to modify your path.
gem env to view the current RubyGems environment:
$ gem env
To see what gems are installed:
$ gem list
To get information about a gem:
$ gem spec gem_name
gem list and
gem spec use the
--local option, which forces gem to search only the local system. This can be overridden with the
--remote flag. Thus, to search for the mysql2 gem:
$ gem list --remote mysql2
To install a gem:
$ gem install mysql2
The process can be sped up somewhat if you do not need local documentation:
$ gem install mysql2 --no-document
To update all installed gems:
$ gem update
Installing gems system-wide
Gems can be installed system wide by running the
gem command as root, appended with the
--no-user-install flag. This flag can be set as default by replacing
/etc/gemrc (system-wide) or
~/.gemrc (per-user, overrides system-wide).
Bundler solves these problems to some extent by packaging gems into your application. See the section below on using bundler.
Bundler allows you to specify which gems your application depends upon, and optionally which version those gems should be. Once this specification is in place, Bundler installs all required gems (including the full gem dependency tree) and logs the results for later inspection. By default, Bundler installs gems into a shared location, but they can also be installed directly into your application. When your application is run, Bundler provides the correct version of each gem, even if multiple versions of each gem have been installed. This requires a little bit of work: applications should be called with
bundle exec, and two lines of boilerplate code must be placed in your application's main executable.
To install Bundler:
$ gem install bundler
To start a new bundle:
$ bundle init
Gemfile in the current directory (created by bundle init) and list your required gems:
gem "rails", "3.2.9" gem "mysql2"
Run the following to install gems into
$ bundle install
Alternatively, run the following to install gems to
.bundle in the working directory:
$ bundle config set --local path '.bundle'
Do not forget to edit your main executable:
#!/usr/bin/env ruby # "This will automatically discover your Gemfile, and make all of the gems in # your Gemfile available to Ruby." https://bundler.io/rationale.html require 'bundler/setup' ...
Finally, run your program:
bundle exec main_executable_name.rb
Managing RubyGems using pacman
This option provides the following advantages:
- Gems are updated along with the rest of your system.
- Installed gems are available system-wide, instead of being available only to the user who installed them.
The repository is maintained by the Arch developer anatolik at https://pkgbuild.com/~anatolik/quarry/. It contains many popular gems and new gems can be added upon request.
See Unofficial user repositories#quarry to enable it.
Then install the required gem. The name of the package is
General questions can be asked at https://bbs.archlinux.org/viewtopic.php?id=182729.
Pry is a powerful alternative to the standard IRB shell for Ruby. It features syntax highlighting, a flexible plugin architecture, runtime invocation and source and documentation browsing.
$gem install pry $pry