int_ctrl_cmd_is_null
int_ctrl_cmd_is_null(e->cmd_defns))
if (int_ctrl_cmd_is_null(e->cmd_defns + idx))
while (!int_ctrl_cmd_is_null(defn) &&
if (int_ctrl_cmd_is_null(defn))
while (!int_ctrl_cmd_is_null(defn) && (defn->cmd_num < num)) {