def setup_output_dir(op_dir, force)
      flag_file = output_flag_file(op_dir)
      if File.exist?(op_dir)
        unless File.directory?(op_dir)
          error "'#{op_dir}' exists, and is not a directory" 
        end
        begin
          created = File.read(flag_file)
        rescue SystemCallError
          error "\nDirectory #{op_dir} already exists, but it looks like it\n" +
            "isn't an RDoc directory. Because RDoc doesn't want to risk\n" +
            "destroying any of your existing files, you'll need to\n" +
            "specify a different output directory name (using the\n" +
            "--op <dir> option).\n\n"
        else
          last = (Time.parse(created) unless force rescue nil)
        end
      else
        File.makedirs(op_dir)
      end
      last
    end
def setup_output_dir(op_dir, force)
      flag_file = output_flag_file(op_dir)
      if File.exist?(op_dir)
        unless File.directory?(op_dir)
          error "'#{op_dir}' exists, and is not a directory" 
        end
        begin
          created = File.read(flag_file)
        rescue SystemCallError
          error "\nDirectory #{op_dir} already exists, but it looks like it\n" +
            "isn't an RDoc directory. Because RDoc doesn't want to risk\n" +
            "destroying any of your existing files, you'll need to\n" +
            "specify a different output directory name (using the\n" +
            "--op <dir> option).\n\n"
        else
          last = (Time.parse(created) unless force rescue nil)
        end
      else
        File.makedirs(op_dir)
      end
      last
    end
Create an output dir if it doesn't exist. If it does
 exist, but doesn't contain the flag file <tt>created.rid</tt>
 then we refuse to use it, as we may clobber some
 manually generated documentation