X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=man%2Fcurs_bkgrnd.3x;h=84a2984bc0ec268b7bc853cf6941c147ffe1a227;hp=2bbb4fce4581b8ed8e8f2507de1da75000bdbeca;hb=e5d1530ca229aef94a3c84ad33f8ae89f35c4045;hpb=6a530b46563470c2ca73579d1994a0c8e275dd98

diff --git a/man/curs_bkgrnd.3x b/man/curs_bkgrnd.3x
index 2bbb4fce..84a2984b 100644
--- a/man/curs_bkgrnd.3x
+++ b/man/curs_bkgrnd.3x
@@ -1,5 +1,6 @@
 .\"***************************************************************************
-.\" Copyright (c) 2002-2012,2015 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            *
@@ -26,9 +27,10 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
-.\" $Id: curs_bkgrnd.3x,v 1.6 2015/07/21 00:18:42 tom Exp $
+.\" $Id: curs_bkgrnd.3x,v 1.12 2020/10/17 23:13:15 tom Exp $
 .de bP
-.IP \(bu 4
+.ie n  .IP \(bu 4
+.el    .IP \(bu 2
 ..
 .TH curs_bkgrnd 3X ""
 .SH NAME
@@ -45,11 +47,11 @@
 \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
@@ -62,7 +64,8 @@ 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
@@ -87,19 +90,32 @@ appears, it is changed to the new background character.
 .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.
+.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)