getnstr is equivalent to a series of calls to
getch, until a newline or carriage return is received (the
terminating character is not included in the returned string). The
resulting string is returned.
getnstr reads at most n characters, thus preventing a
possible overflow of the input buffer. Any attempt to enter more
characters (other than the terminating newline or carriage return)
causes a beep. Function keys also cause a beep and are ignored.
The user’s erase and kill characters are interpreted. If keypad mode
is on for the window,
both considered equivalent to the user’s kill character.
Characters input are echoed only if
echo! is currently on. In
that case, backspace is echoed as deletion of the previous character
(typically a left motion).
If a SIGWINCH interrupts the function, it will return the integer value of KEY_RESIZE instead of a string.