parse_flag_names
bits = parse_flag_names(p + 1, 0);
mask = parse_flag_names(optarg, 0);
bits = parse_flag_names(p + 1, 0);
mask = parse_flag_names(optarg, 1);
bits = parse_flag_names(optarg, 0);
mask = parse_flag_names(optarg, 0);
uint64_t flags = parse_flag_names(optarg, 0);