execute

# File lib/rubygems/commands/setup_command.rb, line 122
  def execute
    @verbose = Gem.configuration.really_verbose

    install_destdir = options[:destdir]

    unless install_destdir.empty? then
      ENV['GEM_HOME'] ||= File.join(install_destdir,
                                    Gem.default_dir.gsub(/^[a-zA-Z]:/, ''))
    end

    check_ruby_version

    require 'fileutils'
    if Gem.configuration.really_verbose then
      extend FileUtils::Verbose
    else
      extend FileUtils
    end

    lib_dir, bin_dir = make_destination_dirs install_destdir

    install_lib lib_dir

    install_executables bin_dir

    remove_old_bin_files bin_dir

    remove_old_lib_files lib_dir

    install_default_bundler_gem

    say "RubyGems #{Gem::VERSION} installed"

    regenerate_binstubs if options[:regenerate_binstubs]

    uninstall_old_gemcutter

    documentation_success = install_rdoc

    say
    if @verbose then
      say "-" * 78
      say
    end

    if options[:previous_version].empty?
      options[:previous_version] = Gem::VERSION.sub(/[0-9]+$/, '0')
    end

    options[:previous_version] = Gem::Version.new(options[:previous_version])

    show_release_notes

    say
    say "-" * 78
    say

    say "RubyGems installed the following executables:"
    say @bin_file_names.map { |name| "\t#{name}\n" }
    say

    unless @bin_file_names.grep(/#{File::SEPARATOR}gem$/) then
      say "If `gem` was installed by a previous RubyGems installation, you may need"
      say "to remove it by hand."
      say
    end

    if documentation_success
      if options[:document].include? 'rdoc' then
        say "Rdoc documentation was installed. You may now invoke:"
        say "  gem server"
        say "and then peruse beautifully formatted documentation for your gems"
        say "with your web browser."
        say "If you do not wish to install this documentation in the future, use the"
        say "--no-document flag, or set it as the default in your ~/.gemrc file. See"
        say "'gem help env' for details."
        say
      end

      if options[:document].include? 'ri' then
        say "Ruby Interactive (ri) documentation was installed. ri is kind of like man "
        say "pages for Ruby libraries. You may access it like this:"
        say "  ri Classname"
        say "  ri Classname.class_method"
        say "  ri Classname#instance_method"
        say "If you do not wish to install this documentation in the future, use the"
        say "--no-document flag, or set it as the default in your ~/.gemrc file. See"
        say "'gem help env' for details."
        say
      end
    end
  end