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.\" $Id: curs_beep.3x,v 1.31 2024/05/18 20:06:33 tom Exp $
.TH curs_beep 3X 2024-05-18 "ncurses @NCURSES_MAJOR@.@NCURSES_MINOR@" "Library calls"
.SH NAME
\fB\%beep\fP,
\fB\%flash\fP \-
ring the (visual) bell of the terminal with \fIcurses\fR
.SH SYNOPSIS
.nf
\fB#include <curses.h>
.PP
\fBint beep(void);
\fBint flash(void);
.fi
.SH DESCRIPTION
.B beep
and
.B flash
alert the terminal user:
the former by sounding the terminal's audible alarm,
and the latter by visibly attracting user attention.
Commonly,
a terminal implements a visual bell by momentarily reversing the
character foreground and background colors on the entire display;
even a monochrome device can do this.
These functions each attempt the other alert type if the one requested
is unavailable.
If neither is available,
.I curses
performs no action.
Nearly all terminals have an audible alert mechanism such as a bell or
piezoelectric buzzer,
but only some can flash the screen.
.SH RETURN VALUE
These functions return
.B OK
on success and
.B ERR
on failure.
.PP
In
.IR \%ncurses ","
.B beep
and
.B flash
return
.B OK
if the terminal type supports the corresponding capability:
.B bell
.RB ( bel )
for
.B beep
and
.B \%flash_screen
.RB ( flash )
for
.BR flash "."
Otherwise they return
.BR ERR "."
.SH EXTENSIONS
In
.IR \%ncurses ","
these functions can return
.BR ERR "."
.SH PORTABILITY
X/Open Curses,
Issue 4 describes these functions.
It specifies no error conditions for them.
.PP
On SVr4
.IR curses ","
they always return
.BR OK ","
and X/Open Curses specifies them as doing so.
.SH HISTORY
.B beep
and
.B flash
appeared in SVr2 (1984).
.SH SEE ALSO
\fB\%curses\fP(3X),
\fB\%terminfo\fP(5)