Ruby – Gems

[vagrant@puppetmaster /]$ gem --help
RubyGems is a sophisticated package manager for Ruby.  This is a
basic help message containing pointers to more information.

  Usage:
    gem -h/--help
    gem -v/--version
    gem command [arguments...] [options...]

  Examples:
    gem install rake
    gem list --local
    gem build package.gemspec
    gem help install

  Further help:
    gem help commands            list all 'gem' commands
    gem help examples            show some examples of usage
    gem help gem_dependencies    gem dependencies file guide
    gem help platforms           gem platforms guide
    gem help            show help on COMMAND
                                   (e.g. 'gem help install')
    gem server                   present a web page at
                                 http://localhost:8808/
                                 with info about installed gems
  Further information:
    http://guides.rubygems.org
[vagrant@puppetmaster /]$ 

Also see:

[vagrant@puppetmaster pod_env]$ gem environment
RubyGems Environment:
  - RUBYGEMS VERSION: 2.4.4
  - RUBY VERSION: 1.9.3 (2014-11-13 patchlevel 551) [x86_64-linux]
  - INSTALLATION DIRECTORY: /usr/local/rvm/gems/ruby-1.9.3-p551
  - RUBY EXECUTABLE: /usr/local/rvm/rubies/ruby-1.9.3-p551/bin/ruby
  - EXECUTABLE DIRECTORY: /usr/local/rvm/gems/ruby-1.9.3-p551/bin
  - SPEC CACHE DIRECTORY: /home/vagrant/.gem/specs
  - SYSTEM CONFIGURATION DIRECTORY: /usr/local/rvm/rubies/ruby-1.9.3-p551/etc
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-linux
  - GEM PATHS:
     - /usr/local/rvm/gems/ruby-1.9.3-p551
     - /usr/local/rvm/gems/ruby-1.9.3-p551@global
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - https://rubygems.org/
  - SHELL PATH:
     - /usr/local/rvm/gems/ruby-1.9.3-p551/bin
     - /usr/local/rvm/gems/ruby-1.9.3-p551@global/bin
     - /usr/local/rvm/rubies/ruby-1.9.3-p551/bin
     - /usr/lib64/qt-3.3/bin
     - /usr/local/bin
     - /usr/bin
     - /bin
     - /usr/local/sbin
     - /usr/sbin
     - /sbin
     - /usr/local/rvm/bin
     - /home/vagrant/bin
[vagrant@puppetmaster pod_env]$ 

If you want to see where all the gems are, cd into the “INSTALLATION DIRECTORY” or “GEM PATHS” (as shown above). Then you can view all gems there.

http://www.pluralsight.com/courses/building-linux-server-for-ruby-on-rails

http://guides.rubygems.org/what-is-a-gem/

http://guides.rubygems.org/

http://guides.rubygems.org/rubygems-basics/

Gems is basically the ruby equivalent of the linux yum command.