ncurses 6.2 - patch 20201205

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

diff --git a/man/curs_bkgrnd.3x b/man/curs_bkgrnd.3x
index 43112a79ab79360c0423e4743e817a560add005a..84a2984bc0ec268b7bc853cf6941c147ffe1a227 100644 (file)
--- a/man/curs_bkgrnd.3x
+++ b/man/curs_bkgrnd.3x
@@ -1,5 +1,6 @@
 .\"***************************************************************************
-.\" Copyright (c) 2002-2006,2010 Free Software Foundation, Inc.              *
+.\" Copyright 2018,2020 Thomas E. Dickey                                     *
+.\" Copyright 2002-2015,2017 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            *
@@ -26,7 +27,11 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
-.\" $Id: curs_bkgrnd.3x,v 1.4 2010/12/04 18:49:20 tom Exp $
+.\" $Id: curs_bkgrnd.3x,v 1.12 2020/10/17 23:13:15 tom Exp $
+.de bP
+.ie n  .IP \(bu 4
+.el    .IP \(bu 2
+..
 .TH curs_bkgrnd 3X ""
 .SH NAME
 \fBbkgrnd\fR,
@@ -42,22 +47,25 @@
 \fBint bkgrnd(\fR\fB const cchar_t *\fR\fIwch\fR\fB);\fR
 .br
 \fBint wbkgrnd(\fR\fB WINDOW *\fR\fIwin\fR\fB, const cchar_t *\fR\fIwch\fR\fB);\fR
-.br
+.sp
 \fBvoid bkgrndset(const cchar_t *\fR\fIwch\fR \fB);\fR
 .br
 \fBvoid wbkgrndset(WINDOW *\fR\fIwin\fR\fB, const cchar_t *\fR\fIwch\fR\fB);\fR
-.br
+.sp
 \fBint getbkgrnd(cchar_t *\fR\fIwch\fR\fB);\fR
 .br
 \fBint wgetbkgrnd(WINDOW *\fR\fIwin\fR\fB, cchar_t *\fR\fIwch\fR\fB);\fR
 .br
 .SH DESCRIPTION
+.SS bkgrndset
+.PP
 The \fBbkgrndset\fR and \fBwbkgrndset\fR routines manipulate the
 background of the named window.
 The window background is a \fBcchar_t\fR consisting of
 any combination of attributes (i.e., rendition) and a complex character.
 The attribute part of the background is combined (OR'ed) with all non-blank
-characters that are written into the window with \fBwaddch\fR.  Both
+characters that are written into the window with \fBwaddch\fR.
+Both
 the character and attribute parts of the background are combined with
 the blank characters.
 The background becomes a property of the
@@ -67,34 +75,47 @@ insert/delete line/character operations.
 To the extent possible on a
 particular terminal, the attribute part of the background is displayed
 as the graphic rendition of the character put on the screen.
+.SS bkgrnd
 .PP
 The \fBbkgrnd\fR and \fBwbkgrnd\fR functions
 set the background property of the current or specified window
 and then apply this setting to every character position in that window:
-.RS
-.PP
+.bP
 The rendition of every character on the screen is changed to
 the new background rendition.
-.PP
+.bP
 Wherever the former background character
 appears, it is changed to the new background character.
-.RE
+.SS getbkgrnd
 .PP
 The \fBgetbkgrnd\fR function returns the given window's current background
 character/attribute pair via the \fBwch\fR pointer.
-.
+If the given window pointer is null,
+the character is not updated (but no error returned).
 .SH NOTES
 Note that
 \fBbkgrnd\fR,
 \fBbkgrndset\fR, and
 \fBgetbkgrnd\fR
 may be macros.
-.SH RETURN VALUES
+.PP
+X/Open Curses does not provide details on how the rendition is changed.
+This implementation follows the approach used in SVr4 curses,
+which is explained in the manual page for \fBwbkgd\fP.
+.SH RETURN VALUE
+.PP
 The \fBbkgrndset\fR and \fBwbkgrndset\fR routines do not return a value.
 .PP
 Upon successful completion, the other functions return \fBOK\fR.
-Otherwise, they return \fBERR\fR.
+Otherwise, they return \fBERR\fR:
+.bP
 A null window pointer is treated as an error.
+.bP
+A null character pointer is treated as an error.
+.SH PORTABILITY
+.PP
+These functions are described in the XSI Curses standard, Issue 4
+(X/Open Curses).
 .SH SEE ALSO
 \fBcurses\fR(3X),
 \fBcurs_bkgd\fR(3X)