key_defined(3x)                                         key_defined(3x)
       key_defined - check if a keycode is defined
       #include <curses.h>
       int key_defined(const char *definition);
       This is an extension to the curses library.  It permits an
       application to determine if a string is currently bound to
       any keycode.
       If  the  string  is bound to a keycode, its value (greater
       than zero) is returned.  If no keycode is bound,  zero  is
       returned.   If  the  string  conflicts with longer strings
       which are bound to keys, -1 is returned.
       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  con-
       ditioned using NCURSES_VERSION.
       define_key(3x).
       Thomas Dickey.
                                                        key_defined(3x)