gistfile1.rb

def r(this)
  require this
  puts "#{this} is now loaded."
rescue LoadError
  puts "The gem '#{this}' is missing."
  puts "Should I install it? [y/n]"
  if gets =~ /yes|y/i
    puts "Installing #{this}, hold on."
    if `gem install #{this}` =~ /Successfully/
      Gem.clear_paths
      require this
      puts "Done, gem loaded."
    end
  else
    puts "Okey, goodbye."
  end
end