execute

# File lib/rubygems/commands/cleanup_command.rb, line 36
  def execute
    say "Cleaning up installed gems..."
    primary_gems = {}

    Gem::Specification.each do |spec|
      if primary_gems[spec.name].nil? or
         primary_gems[spec.name].version < spec.version then
        primary_gems[spec.name] = spec
      end
    end

    gems_to_cleanup = unless options[:args].empty? then
                        options[:args].map do |gem_name|
                          Gem::Specification.find_all_by_name gem_name
                        end.flatten
                      else
                        Gem::Specification.to_a
                      end

    gems_to_cleanup = gems_to_cleanup.select { |spec|
      primary_gems[spec.name].version != spec.version
    }

    deplist = Gem::DependencyList.new
    gems_to_cleanup.uniq.each do |spec| deplist.add spec end

    deps = deplist.strongly_connected_components.flatten.reverse

    original_path = Gem.path

    deps.each do |spec|
      if options[:dryrun] then
        say "Dry Run Mode: Would uninstall #{spec.full_name}"
      else
        say "Attempting to uninstall #{spec.full_name}"

        options[:args] = [spec.name]

        uninstall_options = {
          :executables => false,
          :version => "= #{spec.version}",
        }

        uninstall_options[:user_install] = Gem.user_dir == spec.base_dir

        uninstaller = Gem::Uninstaller.new spec.name, uninstall_options

        begin
          uninstaller.uninstall
        rescue Gem::DependencyRemovalException, Gem::InstallError,
               Gem::GemNotInHomeException, Gem::FilePermissionError => e
          say "Unable to uninstall #{spec.full_name}:"
          say "\t#{e.class}: #{e.message}"
        end
      end

      # Restore path Gem::Uninstaller may have change
      Gem.use_paths(*original_path)
    end

    say "Clean Up Complete"
  end