ncurses 6.2 - patch 20201212

[ncurses.git] / man / curs_clear.3x

diff --git a/man/curs_clear.3x b/man/curs_clear.3x
index fa7723af4fe8a00e8ca69a6805f33837ca04544e..d86acbde6b000392b698140a1130d2e22d3d6f9d 100644 (file)
--- a/man/curs_clear.3x
+++ b/man/curs_clear.3x
@@ -1,5 +1,6 @@
 .\"***************************************************************************
-.\" Copyright (c) 1998,2005 Free Software Foundation, Inc.                   *
+.\" Copyright 2018,2020 Thomas E. Dickey                                     *
+.\" Copyright 1998-2010,2016 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            *
@@ -26,10 +27,14 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
-.\" $Id: curs_clear.3x,v 1.10 2005/10/01 19:34:43 tom Exp $
+.\" $Id: curs_clear.3x,v 1.20 2020/10/24 09:19:37 tom Exp $
 .TH curs_clear 3X ""
 .na
 .hy 0
+.de bP
+.ie n  .IP \(bu 4
+.el    .IP \(bu 2
+..
 .SH NAME
 \fBerase\fR,
 \fBwerase\fR,
@@ -38,27 +43,27 @@
 \fBclrtobot\fR,
 \fBwclrtobot\fR,
 \fBclrtoeol\fR,
-\fBwclrtoeol\fR - clear all or part of a \fBcurses\fR window
+\fBwclrtoeol\fR \- clear all or part of a \fBcurses\fR window
 .ad
 .hy
 .SH SYNOPSIS
-\fB# include <curses.h>\fR
+\fB#include <curses.h>\fR
 .sp
 \fBint erase(void);\fR
 .br
-\fBint werase(WINDOW *win);\fR
-.br
+\fBint werase(WINDOW *\fP\fIwin\fP\fB);\fR
+.sp
 \fBint clear(void);\fR
 .br
-\fBint wclear(WINDOW *win);\fR
-.br
+\fBint wclear(WINDOW *\fP\fIwin\fP\fB);\fR
+.sp
 \fBint clrtobot(void);\fR
 .br
-\fBint wclrtobot(WINDOW *win);\fR
-.br
+\fBint wclrtobot(WINDOW *\fP\fIwin\fP\fB);\fR
+.sp
 \fBint clrtoeol(void);\fR
 .br
-\fBint wclrtoeol(WINDOW *win);\fR
+\fBint wclrtoeol(WINDOW *\fP\fIwin\fP\fB);\fR
 .br
 .SH DESCRIPTION
 The \fBerase\fR and \fBwerase\fR routines copy blanks to every
@@ -70,7 +75,8 @@ cleared completely on the next call to \fBwrefresh\fR for that window
 and repainted from scratch.
 .PP
 The \fBclrtobot\fR and \fBwclrtobot\fR routines erase from the cursor to the
-end of screen.  That is, they erase all lines below the cursor in the window.
+end of screen.
+That is, they erase all lines below the cursor in the window.
 Also, the current line to the right of the cursor, inclusive, is erased.
 .PP
 The \fBclrtoeol\fR and \fBwclrtoeol\fR routines erase the current line
@@ -80,36 +86,49 @@ Blanks created by erasure have the current background rendition (as set
 by \fBwbkgdset\fR) merged into them.
 .SH RETURN VALUE
 All routines return the integer \fBOK\fR on success and \fBERR\fP on failure.
-The SVr4.0 manual says "or a
-non-negative integer if \fBimmedok\fR is set", but this appears to be an error.
 .PP
 X/Open defines no error conditions.
 In this implementation,
-functions using a window pointer parameter return an error if it is null.
+.bP
+functions using a window pointer parameter return an error if it is null
+.bP
+\fBwclrtoeol\fP returns an error
+if the cursor position is about to wrap.
 .SH NOTES
 Note that \fBerase\fR, \fBwerase\fR, \fBclear\fR, \fBwclear\fR,
 \fBclrtobot\fR, and \fBclrtoeol\fR may be macros.
 .SH PORTABILITY
-These functions are described in the XSI Curses standard, Issue 4.  The
+These functions are described in the XSI Curses standard, Issue 4.
+The
 standard specifies that they return \fBERR\fR on failure, but specifies no
 error conditions.
 .PP
+The SVr4.0 manual says that these functions could
+return "a non-negative integer if \fBimmedok\fR is set",
+referring to the return-value of \fBwrefresh\fP.
+In that implementation, \fBwrefresh\fP would return a count of
+the number of characters written to the terminal.
+.PP
 Some historic curses implementations had, as an undocumented feature, the
 ability to do the equivalent of \fBclearok(..., 1)\fR by saying
-\fBtouchwin(stdscr)\fR or \fBclear(stdscr)\fR.  This will not work under
+\fBtouchwin(stdscr)\fR or \fBclear(stdscr)\fR.
+This will not work under
 ncurses.
 .PP
 This implementation, and others such as Solaris,
 sets the current position to 0,0 after erasing
-via \fBwerase()\fP and \fBwclear()\fP.
+via \fBwerase\fP and \fBwclear\fP.
 That fact is not documented in other implementations,
 and may not be true of implementations
 which were not derived from SVr4 source.
+.PP
+Not obvious from the description,
+most implementations clear the screen after \fBwclear\fP
+even for a subwindow or derived window.
+If you do not want to clear the screen during the next \fBwrefresh\fP,
+use \fBwerase\fP instead.
 .SH SEE ALSO
-\fBcurses\fR(3X), \fBcurs_outopts\fR(3X), \fBcurs_refresh\fR(3X)
-.\"#
-.\"# The following sets edit modes for GNU EMACS
-.\"# Local Variables:
-.\"# mode:nroff
-.\"# fill-column:79
-.\"# End:
+\fBcurses\fR(3X),
+\fBcurs_outopts\fR(3X),
+\fBcurs_refresh\fR(3X),
+\fBcurs_variables\fR(3X)