.Bf -symbolic These interfaces are obsoleted by ioctl(2).
The stty function sets the state of the terminal associated with fd. The gtty function retrieves the state of the terminal associated with fd. To set the state of a terminal the call must have write permission.
The stty call is actually ioctl(fd, TIOCSETP, buf), while the gtty call is ioctl(fd, TIOCGETP, buf). See ioctl(2) and tty(4) for an explanation.
If the call is successful 0 is returned, otherwise -1 is returned and the global variable errno contains the reason for the failure.