anchor.diff:  get_arch() ->
       Words = integer_to_list(8 * erlang:system_info(wordsize)),
       erlang:system_info(system_architecture) ++ "-" ++ Words.
  -
  -get_os() ->
  -    Arch = erlang:system_info(system_architecture),
  -    case match_first([{"linux", linux}, {"darwin", darwin}], Arch) of
  -        nomatch ->
  -            {unknown, Arch};
  -        ArchAtom ->
  -            ArchAtom
  -    end.
   
   %%
   %% Options = [Option] -- defaults to [use_stdout, abort_on_error]
  
positive.code: %% ====================================================================
  %% Internal functions
  %% ====================================================================
  
  match_first([], _Val) ->
      nomatch;
  match_first([{Regex, MatchValue} | Rest], Val) ->
      case re:run(Val, Regex, [{capture, none}]) of
          match ->
              MatchValue;
          nomatch ->
             match_first(Rest, Val)
      end.
  
  expand_sh_flag(return_on_error) ->
      {error_handler,
  
negative.code: -export([get_cwd/0,
           is_arch/1,
           get_arch/0,
           sh/2,
           find_files/2,
           now_str/0,
  