code: func scanFiles(paths chan string) {
  	walker := func(path string, info os.FileInfo, err error) error {
  		log.Infof("Found %s", path)
  		if err != nil {
  			return err
  		}
  
  		if info.Mode().IsRegular() {
  			paths <- path
  		}
  		return nil
  	}
  
  	for _, path := range flag.Args() {
  		err := filepath.Walk(path, walker)
  		if err != nil {
  			log.Errorf("Walk failed: %v", err)
  		}
  	}
  	close(paths)
  }
docs: // scanFiles walks the files listed in the arguments. These files may
  // be either certificate files or directories containing certificates.