ncurses 6.0 - patch 20170422

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

diff --git a/man/curs_addch.3x b/man/curs_addch.3x
index 02314d4ab5ba7eaf1ca81b9e5726375562200dad..cc3a75fd67b8f4bd9406a1e6d1318b9408488267 100644 (file)
--- a/man/curs_addch.3x
+++ b/man/curs_addch.3x
@@ -1,6 +1,6 @@
 '\" t
 .\"***************************************************************************
-.\" Copyright (c) 1998-2014,2015 Free Software Foundation, Inc.              *
+.\" Copyright (c) 1998-2015,2017 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            *
@@ -27,7 +27,7 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
-.\" $Id: curs_addch.3x,v 1.35 2015/05/13 19:18:37 tom Exp $
+.\" $Id: curs_addch.3x,v 1.39 2017/04/17 00:14:02 tom Exp $
 .TH curs_addch 3X ""
 .de bP
 .IP \(bu 4
@@ -55,9 +55,10 @@
 \fBint wechochar(WINDOW *win, const chtype ch);\fR
 .br
 .SH DESCRIPTION
+.SS Adding characters
 The \fBaddch\fR, \fBwaddch\fR, \fBmvaddch\fR and \fBmvwaddch\fR routines put
 the character \fIch\fR into the given window at its current window position,
-which is then advanced.  They are analogous to \fBputchar\fR in \fBstdio\fR(3).
+which is then advanced.  They are analogous to \fBputchar\fR(3) in \fBstdio\fR(3).
 If the advance is at the right margin:
 .bP
 The cursor automatically wraps to the beginning of the next line.
@@ -94,12 +95,13 @@ the ^-representation of the control character.
 Video attributes can be combined with a character argument passed to
 \fBaddch\fR or related functions by logical-ORing them into the character.
 (Thus, text, including attributes, can be copied from one place to another
-using \fBinch\fR and \fBaddch\fR.)  See the \fBcurs_attr\fR(3X) page for
+using \fBinch\fR(3X) and \fBaddch\fR.)  See the \fBcurs_attr\fR(3X) page for
 values of predefined video attribute constants that can be usefully OR'ed
 into characters.
+.SS Echoing characters
 .PP
 The \fBechochar\fR and \fBwechochar\fR routines are equivalent to a call to
-\fBaddch\fR followed by a call to \fBrefresh\fR, or a call to \fBwaddch\fR
+\fBaddch\fR followed by a call to \fBrefresh\fR(3X), or a call to \fBwaddch\fR
 followed by a call to \fBwrefresh\fR.  The knowledge that only a single
 character is being output is used and, for non-control characters, a
 considerable performance gain may be seen by using these routines instead of
@@ -108,7 +110,10 @@ their equivalents.
 The following variables may be used to add line drawing characters to the
 screen with routines of the \fBaddch\fR family.  The default character listed
 below is used if the \fBacsc\fR capability does not define a terminal-specific
-replacement for it.
+replacement for it,
+or if the terminal and locale configuration requires Unicode but the
+library is unable to use Unicode.
+.PP
 The names are taken from VT100 nomenclature.
 .PP
 .TS
@@ -183,6 +188,18 @@ include \fBacsc\fR strings in which their key characters (pryz{|}) are
 embedded, and a second-hand list of their character descriptions has come
 to light.  The ACS-prefixed names for them were invented for \fBncurses\fR(3X).
 .LP
+The \fIdisplayed\fP values for the \fIACS_\fP and \fIWACS_\fP constants
+depend on 
+.bP
+the library configuration, i.e., \fBncurses\fP versus \fBncursesw\fP,
+where the latter is capable of displaying Unicode while the former is not, and
+.bP
+whether the \fIlocale\fP uses UTF-8 encoding.
+.LP
+In certain cases, the terminal is unable to display line-drawing characters
+except by using UTF-8 (see the discussion of \fBNCURSES_NO_UTF8_ACS\fP in
+ncurses(3X)).
+.LP
 The \fBTABSIZE\fR variable is implemented in some versions of curses,
 but is not part of X/Open curses.
 .LP