dot.erlang

%% If running an interactive shell
proplists:is_defined(noshell, init:get_arguments()) == false andalso begin
    %% Depending on the install method DocshBase0 definition is rewritten
    %% with sed or kept intact.
    DocshBase0 = "$DOCSH_BASE",
    NextStep = case {code:ensure_loaded(docsh), DocshBase0, os:getenv("DOCSH_BASE")} of
        {{module, docsh}, _, _} ->
            %% The code path already contains docsh.
            ok;
        {_, "$" ++ _, false} ->
            %% If DocshBase0 starts with a $, the env variable of the same name
            %% ought to be set. If it's not - we have a configuration error.
            {error, env_not_set};
        {_, "$" ++ _, Base} ->
            {add_path, Base};
        _ ->
            %% We assume that if the env variable is not set and docsh is not loadable yet,
            %% then DocshBase0 should've been expanded during installation to an absolute path.
            {add_path, DocshBase0}
    end,
    case NextStep of
        {error, env_not_set} ->
            io:format("docsh error: DOCSH_BASE not set, docsh not enabled~n~n");
        ok ->
            docsh:activated(path);
        {add_path, BasePath} ->
            [ code:add_path(Dir)
              || Suffix <- ["/ebin", "/_build/default/lib/docsh/ebin"],
                 Dir <- [filename:join([BasePath, Suffix])],
                 filelib:is_dir(Dir) ],
            code:add_path(BasePath ++ "/_build/default/lib/docsh/ebin"),
            docsh:activated(path)
    end,
    case code:ensure_loaded(docsh) of
        {error, _} ->
            io:format("docsh error: docsh can't be loaded~n~n");
        {module, docsh} ->
            UserDefault = case os:getenv("DOCSH_USER_DEFAULT") of
                false -> os:getenv("HOME") ++ "/.erlang.d/user_default";
                [_|_] = Dir -> Dir
            end,
            case code:load_abs(UserDefault) of
                {error, _} ->
                    io:format("docsh error: shell extensions not available~n~n");
                {module, user_default} ->
                    docsh:activated(user_default)
            end
    end
end.