code: func registerFlags(c *cli.Config, f *flag.FlagSet) {
  	f.BoolVar(&c.List, "list", false, "list possible scanners")
  	f.StringVar(&c.Family, "family", "", "scanner family regular expression")
  	f.StringVar(&c.Scanner, "scanner", "", "scanner regular expression")
  	f.DurationVar(&c.Timeout, "timeout", 5*time.Minute, "duration (ns, us, ms, s, m, h) to scan each host before timing out")
  	f.StringVar(&c.CSVFile, "csv", "", "file containing CSV of hosts")
  	f.IntVar(&c.NumWorkers, "num-workers", 10, "number of workers to use for scan")
  	f.IntVar(&c.MaxHosts, "max-hosts", 100, "maximum number of hosts to scan")
  	f.StringVar(&c.IP, "ip", "", "remote server ip")
  	f.StringVar(&c.CABundleFile, "ca-bundle", "", "path to root certificate store")
  }
docs: // registerFlags defines all cfssl command flags and associates their values with variables.