# File lib/rubygems/gem_commands.rb, line 105
    def add_install_update_options
      add_option('-i', '--install-dir DIR',
                 'Gem repository directory to get installed',
                 'gems.') do |value, options|
        options[:install_dir] = File.expand_path(value)
      end

      add_option('-B', '--build-root DIR', 
  'Temporary installation root. Useful for building packages.') do
  |value, options|
        options[:build_root] = File.expand_path(value)
      end

      add_option('-d', '--[no-]rdoc', 
                 'Generate RDoc documentation for the gem on',
                 'install') do |value, options|
        options[:generate_rdoc] = value
      end

      add_option('--[no-]ri', 
                 'Generate RI documentation for the gem on',
                 'install') do |value, options|
        options[:generate_ri] = value
      end

      add_option('-E', '--env-shebang',
                 "Rewrite the shebang line on installed",
                 "scripts to use /usr/bin/env") do |value, options|
        options[:env_shebang] = value
      end

      add_option('-f', '--[no-]force', 
                 'Force gem to install, bypassing dependency',
                 'checks') do |value, options|
        options[:force] = value
      end

      add_option('-t', '--[no-]test', 
        'Run unit tests prior to installation') do 
        |value, options|
        options[:test] = value
      end

      add_option('-w', '--[no-]wrappers', 
        'Use bin wrappers for executables',
        'Not available on dosish platforms') do 
        |value, options|
        options[:wrappers] = value
      end

      add_option('-P', '--trust-policy POLICY', 
        'Specify gem trust policy.') do 
        |value, options|
        options[:security_policy] = value
      end

      add_option('--ignore-dependencies',
        'Do not install any required dependent gems') do 
        |value, options|
        options[:ignore_dependencies] = value
      end

      add_option('-y', '--include-dependencies',
                 'Unconditionally install the required',
                 'dependent gems') do |value, options|
        options[:include_dependencies] = value
      end
    end