Erlang env var config with validation

-module(env_config).
-export([get/2, get_int/3]).

get(Name, Default) ->
    case os:getenv(Name) of
        false -> Default;
        "" -> Default;
        Value -> Value
    end.

%% Integer env var validated against an inclusive range.
get_int(Name, Default, {Min, Max}) ->
    case get(Name, undefined) of
        undefined -> Default;
        Raw ->
            case string:to_integer(Raw) of
                {Int, ""} when Int >= Min, Int =< Max -> Int;
                _ -> error({invalid_env, Name, Raw})
            end
    end.