get_parameter_revkey( struct para_data_s *para, enum para_name key )
{
    struct para_data_s *r = get_parameter( para, key );
    return r? &r->u.revkey : NULL;
}
get_parameter_revkey( struct para_data_s *para, enum para_name key )
{
    struct para_data_s *r = get_parameter( para, key );
    return r? &r->u.revkey : NULL;
}