https://invisible-island.net/ncurses/man/
key_defined(3x) Library calls key_defined(3x)
key_defined - obtain key code for an ncurses function key definition
#include <curses.h>
int key_defined(const char * definition);
The key_defined ncurses extension permits a curses application to
determine the function key code, if any, to which the string definition
is bound.
key_defined returns the first key code to which definition is bound if
any exists. If none does, it returns 0. If definition is a prefix of
another bound definition, key_defined returns -1.
key_defined is an ncurses extension.
Applications employing ncurses extensions should condition their use on
the visibility of the NCURSES_VERSION preprocessor macro.
Thomas Dickey
curses(3x), define_key(3x), keybound(3x), keyok(3x)
ncurses 6.5 2025-10-04 key_defined(3x)