private void defineVariables(String line) {

      Matcher varDefn = matchesVarDefn.matcher(line);

      if (varDefn.lookingAt()) {

        String var = varDefn.group(1);

        String val = varDefn.group(2);

        vars.define(var, val);

      } else {

        String[] words = splitWords.split(line);

        for (String var : words) {

          String value = System.getenv(var);

          vars.define(var, value);

        }

      }

    }