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.\" Author: Thomas E. Dickey 1997
.\"
.\" $Id: define_key.3x,v 1.44 2024/05/18 20:04:21 tom Exp $
.TH define_key 3X 2024-05-18 "ncurses @NCURSES_MAJOR@.@NCURSES_MINOR@" "Library calls"
.
.de bP
.ie n  .IP \(bu 4
.el    .IP \(bu 2
..
.
.SH NAME
\fB\%define_key\fP \-
define a \fIcurses\fP function key code
.SH SYNOPSIS
.nf
\fB#include <curses.h>
.PP
\fBint define_key(const char * \fIdefinition\fP, int \fIkey-code\fP);
.fi
.SH DESCRIPTION
The
.B \%define_key
.I \%ncurses
extension permits a
.I curses
application to
.I bind
a string
.I definition
to the function key
.I key-code
returned by \fB\%wgetch\fP(3X)
(wide-character API users:
\fB\%wget_wch\fP(3X))
when \fB\%keypad\fP(3X) is enabled in a window and a function key is
pressed.
.I \%ncurses
interprets such a binding as it does those in the
.I \%term\%info
database entry for the terminal type.
.PP
A
.I definition
of
.B NULL
removes any existing one
.IR key-code "."
Similarly,
a non-positive
.I key-code
removes any existing bindings for
.IR definition "."
.SH RETURN VALUE
.B \%define_key
returns
.B ERR
if
.bP
.I definition
is
.B NULL
and
.I key-code
is nonpositive,
or
.bP
insufficient memory is available to bind
.I definition
to
.IR key-code "."
.PP
Otherwise,
.B \%define_key
returns
.BR OK "."
.SH EXTENSIONS
.B \%define_key
is an
.I \%ncurses
extension.
.SH PORTABILITY
Applications employing
.I \%ncurses
extensions should condition their use on the visibility of the
.B \%NCURSES_VERSION
preprocessor macro.
.PP
NetBSD
.I curses
since 2.0 (2004) supports
.BR \%define_key "."
.SH AUTHORS
Thomas Dickey
.SH SEE ALSO
\fB\%ncurses\fP(3X),
\fB\%keyok\fP(3X),
\fB\%key_defined\fP(3X),
\fB\%keybound\fP(3X),
\fB\%keyok\fP(3X),
\fB\%terminfo\fP(5)