# File lib/bundler/cli.rb, line 300
    def update(*gems)
      sources = Array(options[:source])
      Bundler.ui.level = "warn" if options[:quiet]

      if gems.empty? && sources.empty?
        # We're doing a full update
        Bundler.definition(true)
      else
        # cycle through the requested gems, just to make sure they exist
        lock = Bundler.read_file(Bundler.default_lockfile)
        names = LockfileParser.new(lock).specs.map{ |s| s.name }
        gems.each do |g|
          next if names.include?(g)
          raise GemNotFound, not_found_message(g, names)
        end
        Bundler.definition(:gems => gems, :sources => sources)
      end

      Bundler::Fetcher.disable_endpoint = options["full-index"]

      opts = {"update" => true, "local" => options[:local]}
      # rubygems plugins sometimes hook into the gem install process
      Gem.load_env_plugins if Gem.respond_to?(:load_env_plugins)

      Bundler.definition.validate_ruby!
      Installer.install Bundler.root, Bundler.definition, opts
      Bundler.load.cache if Bundler.root.join("vendor/cache").exist?
      clean if Bundler.settings[:clean] && Bundler.settings[:path]
      Bundler.ui.confirm "Your bundle is updated!"
      Bundler.ui.confirm without_groups_message if Bundler.settings.without.any?
    end