install.rb

    while a = ARGV.shift
      case a
      when /\A--no-harm\z/
        @options['no-harm'] = true
      when /\A--prefix=(.*)\z/
        path = $1
        path = File.expand_path(path) unless path[0,1] == '/'
        @options['install-prefix'] = path
      else
        raise InstallError, "install: unknown option #{a}"
      end
    end
  end


  def print_usage( out )
    out.puts 'Typical Installation Procedure:'
    out.puts "  $ ruby #{File.basename $0} config"
    out.puts "  $ ruby #{File.basename $0} setup"
    out.puts "  # ruby #{File.basename $0} install (may require root privilege)"
    out.puts
    out.puts 'Detailed Usage:'
    out.puts "  ruby #{File.basename $0} <global option>"
    out.puts "  ruby #{File.basename $0} [<global options>] <task> [<task options>]"

    fmt = "  %-20s %s\n"
    out.puts
    out.puts 'Global options:'
    out.printf fmt, '-q,--quiet',   'suppress message outputs'
    out.printf fmt, '   --verbose', 'output messages verbosely'
    out.printf fmt, '-h,--help',    'print this message'
    out.printf fmt, '-v,--version', 'print version and quit'
    out.printf fmt, '   --copyright',  'print copyright and quit'

    out.puts
    out.puts 'Tasks:'
    TASKS.each do |name, desc|
      out.printf "  %-10s  %s\n", name, desc
    end

    out.puts
    out.puts 'Options for config:'
    ConfigTable.each_definition do |name, (default, arg, desc, default2)|
      out.printf "  %-20s %s [%s]\n",
                 '--'+ name + (ConfigTable.bool_config?(name) ? '' : '='+arg),
                 desc,
                 default2 || default
    end
    out.printf "  %-20s %s [%s]\n",
        '--rbconfig=path', 'your rbconfig.rb to load', "running ruby's"

    out.puts
    out.puts 'Options for install:'
    out.printf "  %-20s %s [%s]\n",
        '--no-harm', 'only display what to do if given', 'off'
    out.printf "  %-20s %s [%s]\n",
        '--prefix',  'install path prefix', '$prefix'

    out.puts
  end

  #
  # config
  #

  def exec_config
    super
    @config.save
  end

  #
  # show
  #

  def exec_show
    ConfigTable.each_name do |k|
      v = @config.get_raw(k)
      if not v or v.empty?
        v = '(not specified)'
      end
      printf "%-10s %s\n", k, v
    end
  end

end

### end toplevel.rb

if $0 == __FILE__
  begin
    ToplevelInstaller.invoke
  rescue
    raise if $DEBUG
    $stderr.puts $!.message
    $stderr.puts "Try 'ruby #{$0} --help' for detailed usage."
    exit 1
  end
end