This is an extension to the curses library.
It permits an application to determine the string which is defined
in the terminfo for specific keycodes.
RETURN VALUE
The keycode parameter must be greater than zero, else NULL is returned.
If it does not correspond to a defined key, then NULL is returned.
The count parameter is used to allow the application to iterate
through multiple definitions, counting from zero.
When successful,
the function returns a string which must be freed by the caller.
PORTABILITY
These routines are specific to ncurses. They were not supported on
Version 7, BSD or System V implementations. It is recommended that
any code depending on them be conditioned using NCURSES_VERSION.