code: func GetSize(fd int) (width, height int, err error) {
  	ws, err := unix.IoctlGetWinsize(fd, unix.TIOCGWINSZ)
  	if err != nil {
  		return -1, -1, err
  	}
  	return int(ws.Col), int(ws.Row), nil
  }
docs: // GetSize returns the dimensions of the given terminal.