How to install RubyGems via an automated ruby script

Automated RubyGem Install

#!c:/ruby/bin/ruby.exe
require 'rubygems'
require 'rubygems/gem_runner'
require 'rubygems/exceptions'

def install(lib)
  begin
    Gem::GemRunner.new.run ['install', lib]
  rescue Gem::SystemExitException => e
  end
end

puts "Installing required dependencies"

install 'aws-s3'

puts "Checking dependencies"
require 'aws/s3'

Gem Version Check

#Taken from gem file
required_version = Gem::Requirement.new "> 1.8.3"

unless required_version.satisfied_by? Gem.ruby_version then
  abort "Expected Ruby Version #{required_version}, was #{Gem.ruby_version}"
end