.\"***************************************************************************
.\" Copyright 2018-2023,2024 Thomas E. Dickey                                *
.\" Copyright 1998-2010,2017 Free Software Foundation, Inc.                  *
.\"                                                                          *
.\" Permission is hereby granted, free of charge, to any person obtaining a  *
.\" copy of this software and associated documentation files (the            *
.\" "Software"), to deal in the Software without restriction, including      *
.\" without limitation the rights to use, copy, modify, merge, publish,      *
.\" distribute, distribute with modifications, sublicense, and/or sell       *
.\" copies of the Software, and to permit persons to whom the Software is    *
.\" furnished to do so, subject to the following conditions:                 *
.\"                                                                          *
.\" The above copyright notice and this permission notice shall be included  *
.\" in all copies or substantial portions of the Software.                   *
.\"                                                                          *
.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
.\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
.\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
.\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
.\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
.\" THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
.\"                                                                          *
.\" Except as contained in this notice, the name(s) of the above copyright   *
.\" holders shall not be used in advertising or otherwise to promote the     *
.\" sale, use or other dealings in this Software without prior written       *
.\" authorization.                                                           *
.\"***************************************************************************
.\"
.\" Author: Thomas E. Dickey 1997
.\"
.\" $Id: define_key.3x,v 1.42 2024/03/16 15:35:01 tom Exp $
.TH define_key 3X 2024-03-16 "ncurses 6.5" "Library calls"
.SH NAME
\fB\%define_key\fP \-
define a \fIcurses\fR keycode
.SH SYNOPSIS
.nf
\fB#include <curses.h>
.PP
\fBint define_key(const char *\fIdefinition\fP, int \fIkeycode\fP);
.fi
.SH DESCRIPTION
This is an extension to the \fIcurses\fP library.
It permits an application to define keycodes with their corresponding control
strings,
so that the \fI\%ncurses\fP library will interpret them just as it would
the predefined codes in the terminfo database.
.PP
If \fIdefinition\fP is \fBNULL\fP,
any existing one for the keycode is removed.
Similarly, if the given keycode is negative or zero, any existing string
for the given definition is removed.
.SH RETURN VALUE
Either \fIkeycode\fP must be greater than zero,
or \fIdefinition\fP must be non-\fBNULL\fP,
otherwise \fBERR\fP is returned.
\fBERR\fP may also be returned if there is insufficient memory to allocate the
data to store the definition.
If no error is detected, \fBOK\fP is returned.
.SH PORTABILITY
These routines are specific to \fI\%ncurses\fP.
They were not supported on
Version 7, BSD or System V implementations.
It is recommended that
any code depending on them be conditioned using \fB\%NCURSES_VERSION\fP.
.SH AUTHORS
Thomas Dickey
.SH SEE ALSO
\fB\%keyok\fP(3X),
\fB\%key_defined\fP(3X)