.\"	$NetBSD: curses_clear.3,v 1.4 2019/01/11 06:14:39 dholland Exp $
.\"
.\" Copyright (c) 2002
.\"	Brett Lymn (blymn@NetBSD.org, brett_lymn@yahoo.com.au)
.\"
.\" This code is donated to the NetBSD Foundation by the Author.
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.Dd January 11, 2019
.Dt CURSES_CLEAR 3
.Os
.Sh NAME
.Nm curses_clear ,
.Nm clear ,
.Nm wclear ,
.Nm clearok ,
.Nm clrtobot ,
.Nm clrtoeol ,
.Nm erase ,
.Nm werase ,
.Nm wclrtobot ,
.Nm wclrtoeol
.Nd curses clear window routines
.Sh LIBRARY
.Lb libcurses
.Sh SYNOPSIS
.In curses.h
.Ft int
.Fn clear "void"
.Ft int
.Fn clearok "WINDOW *win" "bool flag"
.Ft int
.Fn clrtobot "void"
.Ft int
.Fn clrtoeol "void"
.Ft int
.Fn erase "void"
.Ft int
.Fn wclear "WINDOW *win"
.Ft int
.Fn werase "WINDOW *win"
.Ft int
.Fn wclrtobot "WINDOW *win"
.Ft int
.Fn wclrtoeol "WINDOW *win"
.Sh DESCRIPTION
These functions clear all or part of
.Dv stdscr
or of the specified window.
.Pp
The
.Fn clear
and
.Fn erase
functions erase all characters on
.Dv stdscr .
These differ in that
.Fn clear
uses
.Fn clearok
to force a complete redraw on the next refresh, and
.Fn erase
does not.
.Fn wclear
and
.Fn werase
perform the same function as
.Fn clear
and
.Fn erase ,
respectively, excepting that the specified window is cleared.
.Pp
By setting
.Fa flag
to
.Dv TRUE ,
the
.Fn clearok
function is used to force the next call to
.Fn wrefresh
to clear and completely redraw the window given in
.Fa win .
.Pp
The function
.Fn clrtobot
will clear
.Dv stdscr
from the current row to the bottom of the screen.
.Fn clrtoeol
will clear
.Dv stdscr
from the current column position to the end of the line.
.Fn wclrtobot
and
.Fn wclrtoeol
are the same as
.Fn clrtobot
and
.Fn clrtoeol ,
respectively, excepting the window specified is operated on instead of
.Dv stdscr .
.Sh RETURN VALUES
Functions returning pointers will return
.Dv NULL
if an error is detected.
The functions that return an int will return one of the following
values:
.Pp
.Bl -tag -width ERR -compact
.It Er OK
The function completed successfully.
.It Er ERR
An error occurred in the function.
.El
.Sh SEE ALSO
.Xr curses_refresh 3
.Sh STANDARDS
The
.Nx
Curses library complies with the X/Open Curses specification, part of the
Single Unix Specification.
.Sh HISTORY
The Curses package appeared in
.Bx 4.0 .