static extern int cfsetspeed(ref struct_termios termios_p, speed_t speed);
static extern speed_t cfgetispeed(ref struct_termios termios_p);
static extern int tcsetattr(int fd, int optional_actions, ref struct_termios termios_p);
static extern void cfmakeraw(ref struct_termios termios_p);
static extern int tcgetattr(int fd, out struct_termios termios_p);