path: root/man/curs_inch.3x
diff options
Diffstat (limited to 'man/curs_inch.3x')
1 files changed, 51 insertions, 10 deletions
diff --git a/man/curs_inch.3x b/man/curs_inch.3x
index 7e1e3b439177..15698c8c6637 100644
--- a/man/curs_inch.3x
+++ b/man/curs_inch.3x
@@ -1,6 +1,6 @@
'\" t
-.\" Copyright (c) 1998-2006,2010 Free Software Foundation, Inc. *
+.\" Copyright (c) 1998-2018,2019 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 *
@@ -27,8 +27,16 @@
.\" authorization. *
-.\" $Id: curs_inch.3x,v 1.17 2010/12/04 18:36:44 tom Exp $
+.\" $Id: curs_inch.3x,v 1.22 2019/11/30 21:06:30 tom Exp $
.TH curs_inch 3X ""
+.ie \n(.g .ds `` \(lq
+.el .ds `` ``
+.ie \n(.g .ds '' \(rq
+.el .ds '' ''
+.de bP
+.ie n .IP \(bu 4
+.el .IP \(bu 2
@@ -47,8 +55,10 @@
These routines return the character, of type \fBchtype\fR, at the current
-position in the named window. If any attributes are set for that position,
-their values are OR'ed into the value returned. Constants defined in
+position in the named window.
+If any attributes are set for that position,
+their values are OR'ed into the value returned.
+Constants defined in
\fB<curses.h>\fR can be used with the \fB&\fR (logical AND) operator to
extract the character or attributes alone.
@@ -62,16 +72,47 @@ l l .
\fBA_COLOR\fR Bit-mask to extract color-pair field information
-Functions with a "mv" prefix first perform a cursor movement using
+Functions with a \*(``mv\*('' prefix first perform a cursor movement using
\fBwmove\fP, and return an error if the position is outside the window,
or if the window pointer is null.
+The \fBwinch\fP function does not return an error if the window contains
+characters larger than 8-bits (255).
+Only the low-order 8 bits of the character are used by \fBwinch\fP.
Note that all of these routines may be macros.
These functions are described in the XSI Curses standard, Issue 4.
-Comparable functions in the wide-character (ncursesw) library are
-described in
+Very old systems (before standardization) provide a different function
+with the same name:
+The \fBwinch\fP function was part of the original BSD curses library,
+which stored a 7-bit character combined with the \fIstandout\fP attribute.
+In BSD curses, \fBwinch\fP returned only the character (as an integer)
+with the \fIstandout\fP attribute removed.
+System V curses added support for several video attributes which
+could be combined with characters in the window.
+Reflecting this improvement, the function was altered to return the
+character combined with all video attributes in a \fBchtype\fP value.
+X/Open Curses does not specify
+the size and layout of attributes, color and character values in
+\fBchtype\fP; it is implementation-dependent.
+This implementation uses 8 bits for character values.
+An application using more bits, e.g., a Unicode value,
+should use the wide-character equivalents to these functions.
+.TP 5
+gives an overview of the WINDOW and \fBchtype\fP data types.
+.TP 5
+goes into more detail, pointing out portability problems and
+constraints on the use of \fBchtype\fP for returning window information.
+.TP 5
+describes comparable functions for the wide-character (ncursesw) library.