code: func getDeviceInfo(mode os.FileMode, rdev uint64) (kind rune, major uint64, minor uint64, err error) {
  	kind = 'b'
  
  	if mode&os.ModeCharDevice != 0 {
  		kind = 'c'
  	}
  
  	major = (rdev >> 8) & 0xfff
  	minor = (rdev & 0xff) | ((rdev >> 12) & 0xfff00)
  
  	return
  }
docs: // Parse the device info out of the mode bits. Separate for testability.