X-Git-Url: http://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=man%2Fcurs_addch.3x;h=c92d12b7109d8d007bc10d94f6b90fd514db4640;hp=664b8da5e42e4a3bff32fb7db9990b0cd135cf99;hb=47d2fb4537d9ad5bb14f4810561a327930ca4280;hpb=cccf831ed7c83410c7f6cec2a43e71e9c4278b4c

diff --git a/man/curs_addch.3x b/man/curs_addch.3x
index 664b8da5..c92d12b7 100644
--- a/man/curs_addch.3x
+++ b/man/curs_addch.3x
@@ -1,6 +1,7 @@
 '\" t
 .\"***************************************************************************
-.\" Copyright (c) 1998-2017,2018 Free Software Foundation, Inc.              *
+.\" Copyright 2018-2019,2020 Thomas E. Dickey                                *
+.\" Copyright 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 +28,7 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
-.\" $Id: curs_addch.3x,v 1.45 2018/05/19 21:03:18 tom Exp $
+.\" $Id: curs_addch.3x,v 1.51 2020/02/02 23:34:34 tom Exp $
 .TH curs_addch 3X ""
 .ie \n(.g .ds `` \(lq
 .el       .ds `` ``
@@ -94,7 +95,8 @@ Tabs are considered to be at every eighth column.
 The tab interval may be altered by setting the \fBTABSIZE\fR variable.
 .PP
 If \fIch\fR is any other control character, it
-is drawn in \fB^\fR\fIX\fR notation.  Calling \fBwinch\fR after adding a
+is drawn in \fB^\fR\fIX\fR notation.
+Calling \fBwinch\fR after adding a
 control character does not return the character itself, but instead returns
 the ^-representation of the control character.
 .PP
@@ -108,13 +110,15 @@ into characters.
 .PP
 The \fBechochar\fR and \fBwechochar\fR routines are equivalent to a call to
 \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
+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
 their equivalents.
 .SS Line Graphics
 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
+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,
 or if the terminal and locale configuration requires Unicode but the
@@ -182,6 +186,31 @@ The defaults specified for forms-drawing characters apply in the POSIX locale.
 X/Open Curses states that the \fIACS_\fP definitions are \fBchar\fP constants.
 For the wide-character implementation (see \fBcurs_add_wch\fP),
 there are analogous \fIWACS_\fP definitions which are \fBcchar_t\fP constants.
+Some implementations are problematic:
+.bP
+Some implementations define the ACS symbols to a constant
+(such as Solaris), while others define those to entries in an array.
+.IP
+This implementation uses an array \fBacs_map\fP, as done in SVr4 curses.
+NetBSD also uses an array, actually named \fB_acs_char\fP, with a \fB#define\fP
+for compatibility.
+.bP
+HPUX curses equates some of the \fIACS_\fP symbols
+to the analogous \fIWACS_\fP symbols as if the \fIACS_\fP symbols were
+wide characters.
+The misdefined symbols are the arrows
+and other symbols which are not used for line-drawing.
+.bP
+X/Open Curses (issues 2 through 7) has a typographical error
+for the ACS_LANTERN symbol, equating its \*(``VT100+ Character\*(''
+to \fBI\fP (capital I), while the header files for SVr4 curses
+and the various implementations use \fBi\fP (lowercase).
+.IP
+None of the terminal descriptions on Unix platforms use uppercase-I,
+except for Solaris (i.e., \fIscreen\fP's terminal description,
+apparently based on the X/Open documentation around 1995).
+On the other hand, the terminal description \fIgs6300\fP
+(AT&T PC6300 with EMOTS Terminal Emulator) uses lowercase-i.
 .LP
 Some ACS symbols
 (ACS_S3,
@@ -192,10 +221,12 @@ ACS_PI,
 ACS_NEQUAL,
 ACS_STERLING)
 were not documented in
-any publicly released System V.  However, many publicly available terminfos
+any publicly released System V.
+However, many publicly available terminfos
 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).
+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 
@@ -219,7 +250,7 @@ that the non-character information (attributes and color) was
 separated from the character information which is packed in a \fBchtype\fP
 to pass to \fBwaddch\fP.
 .PP
-In this implementation, \fBchtype\fP holds eight bits.
+In this implementation, \fBchtype\fP holds an eight-bit character.
 But ncurses allows multibyte characters to be passed in a succession
 of calls to \fBwaddch\fP.
 The other implementations do not do this;
@@ -247,8 +278,9 @@ before attempting call \fBwaddch\fP, and
 call \fBwadd_wch\fP for characters which cannot be handled by \fBwaddch\fP.
 .SS TABSIZE
 .LP
-The \fBTABSIZE\fR variable is implemented in some versions of curses,
-but is not part of X/Open curses.
+The \fBTABSIZE\fR variable is implemented in SVr4 and other versions of curses,
+but is not part of X/Open curses
+(see \fBcurs_variables\fR(3X) for more details).
 .LP
 If \fIch\fR is a carriage return,
 the cursor is moved to the beginning of the current row of the window.