-module(module_cp).

-export([rename_module/3,load_module_copy/1]).

rename_module(Bin, OldName, NewName) ->
    case length(OldName) =/= length(NewName) of
        %% sometimes there are problems if names don't have the same length
        true -> {error,name_lengths_differ};
        false ->
            S = binary_to_list(Bin),
            Tmp = string:replace(S, OldName, NewName),
            RenamedBin = list_to_binary(lists:flatten(Tmp)),
            {ok, RenamedBin}
    end.

load_module_copy(Mod) ->
    ModName = atom_to_list(Mod),
    {Mod, Bin, _} = code:get_object_code(Mod),
    NewName = case ModName of
        [$x|TL] -> [$y|TL];
        [_|TL] -> [$x|TL]
    end,
    {ok, RenamedBin} = rename_module(Bin, ModName, NewName),
    code:load_binary(list_to_atom(NewName), "", RenamedBin).