1.\" $NetBSD: curses_clear.3,v 1.4 2019/01/11 06:14:39 dholland Exp $ 2.\" 3.\" Copyright (c) 2002 4.\" Brett Lymn (blymn@NetBSD.org, brett_lymn@yahoo.com.au) 5.\" 6.\" This code is donated to the NetBSD Foundation by the Author. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. The name of the Author may not be used to endorse or promote 17.\" products derived from this software without specific prior written 18.\" permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" 33.Dd January 11, 2019 34.Dt CURSES_CLEAR 3 35.Os 36.Sh NAME 37.Nm curses_clear , 38.Nm clear , 39.Nm wclear , 40.Nm clearok , 41.Nm clrtobot , 42.Nm clrtoeol , 43.Nm erase , 44.Nm werase , 45.Nm wclrtobot , 46.Nm wclrtoeol 47.Nd curses clear window routines 48.Sh LIBRARY 49.Lb libcurses 50.Sh SYNOPSIS 51.In curses.h 52.Ft int 53.Fn clear "void" 54.Ft int 55.Fn clearok "WINDOW *win" "bool flag" 56.Ft int 57.Fn clrtobot "void" 58.Ft int 59.Fn clrtoeol "void" 60.Ft int 61.Fn erase "void" 62.Ft int 63.Fn wclear "WINDOW *win" 64.Ft int 65.Fn werase "WINDOW *win" 66.Ft int 67.Fn wclrtobot "WINDOW *win" 68.Ft int 69.Fn wclrtoeol "WINDOW *win" 70.Sh DESCRIPTION 71These functions clear all or part of 72.Dv stdscr 73or of the specified window. 74.Pp 75The 76.Fn clear 77and 78.Fn erase 79functions erase all characters on 80.Dv stdscr . 81These differ in that 82.Fn clear 83uses 84.Fn clearok 85to force a complete redraw on the next refresh, and 86.Fn erase 87does not. 88.Fn wclear 89and 90.Fn werase 91perform the same function as 92.Fn clear 93and 94.Fn erase , 95respectively, excepting that the specified window is cleared. 96.Pp 97By setting 98.Fa flag 99to 100.Dv TRUE , 101the 102.Fn clearok 103function is used to force the next call to 104.Fn wrefresh 105to clear and completely redraw the window given in 106.Fa win . 107.Pp 108The function 109.Fn clrtobot 110will clear 111.Dv stdscr 112from the current row to the bottom of the screen. 113.Fn clrtoeol 114will clear 115.Dv stdscr 116from the current column position to the end of the line. 117.Fn wclrtobot 118and 119.Fn wclrtoeol 120are the same as 121.Fn clrtobot 122and 123.Fn clrtoeol , 124respectively, excepting the window specified is operated on instead of 125.Dv stdscr . 126.Sh RETURN VALUES 127Functions returning pointers will return 128.Dv NULL 129if an error is detected. 130The functions that return an int will return one of the following 131values: 132.Pp 133.Bl -tag -width ERR -compact 134.It Er OK 135The function completed successfully. 136.It Er ERR 137An error occurred in the function. 138.El 139.Sh SEE ALSO 140.Xr curses_refresh 3 141.Sh STANDARDS 142The 143.Nx 144Curses library complies with the X/Open Curses specification, part of the 145Single Unix Specification. 146.Sh HISTORY 147The Curses package appeared in 148.Bx 4.0 . 149