code: func MakeRaw(fd uintptr) (*State, error) {
  	termios, err := unix.IoctlGetTermios(int(fd), getTermios)
  	if err != nil {
  		return nil, err
  	}
  
  	var oldState State
  	oldState.termios = Termios(*termios)
  
  	termios.Iflag &^= (unix.IGNBRK | unix.BRKINT | unix.PARMRK | unix.ISTRIP | unix.INLCR | unix.IGNCR | unix.ICRNL | unix.IXON)
  	termios.Oflag &^= unix.OPOST
  	termios.Lflag &^= (unix.ECHO | unix.ECHONL | unix.ICANON | unix.ISIG | unix.IEXTEN)
  	termios.Cflag &^= (unix.CSIZE | unix.PARENB)
  	termios.Cflag |= unix.CS8
  	termios.Cc[unix.VMIN] = 1
  	termios.Cc[unix.VTIME] = 0
  
  	if err := unix.IoctlSetTermios(int(fd), setTermios, termios); err != nil {
  		return nil, err
  	}
  	return &oldState, nil
  }
docs: // MakeRaw put the terminal connected to the given file descriptor into raw
  // mode and returns the previous state of the terminal so that it can be
  // restored.