ncurses 6.0 - patch 20160723

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

diff --git a/man/curs_getch.3x b/man/curs_getch.3x
index e81923f0570cd5cba601b33284166a3e940ed7d8..1196b3d61285592c4430b3f558f1e6b287d994d7 100644 (file)
--- a/man/curs_getch.3x
+++ b/man/curs_getch.3x
@@ -1,6 +1,6 @@
 '\" t
 .\"***************************************************************************
-.\" Copyright (c) 1998-2014,2015 Free Software Foundation, Inc.              *
+.\" Copyright (c) 1998-2015,2016 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_getch.3x,v 1.43 2015/09/19 22:25:05 tom Exp $
+.\" $Id: curs_getch.3x,v 1.47 2016/06/11 22:56:33 tom Exp $
 .TH curs_getch 3X ""
 .na
 .hy 0
@@ -95,10 +95,17 @@ is read.
 .SS Keypad mode
 .PP
 If \fBkeypad\fR is \fBTRUE\fR, and a function key is pressed, the token for
-that function key is returned instead of the raw characters.
-Possible function
-keys are defined in \fB<curses.h>\fR as macros with values outside the range
-of 8-bit characters whose names begin with \fBKEY_\fR.
+that function key is returned instead of the raw characters:
+.bP
+The predefined function
+keys are listed in \fB<curses.h>\fR as macros with values outside the range
+of 8-bit characters.
+Their names begin with \fBKEY_\fR.
+.bP
+Other (user-defined) function keys which may be defined using \fBdefine_key\fP(3X)
+have no names, but also are expected to have values outside the range of
+8-bit characters.
+.PP
 Thus, a variable
 intended to hold the return value of a function key must be of short size or
 larger.
@@ -111,6 +118,13 @@ time, the character is passed through;
 otherwise, the function key value is returned.
 For this reason, many terminals experience a delay between the time
 a user presses the escape key and the escape is returned to the program.
+.PP
+In \fBncurses\fP, the timer normally expires after the value in \fBESCDELAY\fP (see \fBcurs_variables\fP(3X)).
+If \fBnotimeout\fP is \fBTRUE\fP, the timer does not expire;
+it is an infinite (or very large) value.
+Because function keys usually begin with an escape character,
+the terminal may appear to hang in notimeout mode after pressing the escape key
+until another key is pressed.
 .SS Ungetting characters
 .PP
 The \fBungetch\fR routine places \fIch\fR back onto the input queue to be
@@ -118,9 +132,17 @@ returned by the next call to \fBwgetch\fR.
 There is just one input queue for all windows.
 .PP
 .SS Predefined key-codes
-The following special keys, defined in \fB<curses.h>\fR, may be returned by
-\fBgetch\fR if \fBkeypad\fR has been enabled.
+The following special keys are defined in \fB<curses.h>\fR.
+.bP
+Except for the special case \fBKEY_RESIZE\fP,
+it is necessary to enable \fBkeypad\fR for \fBgetch\fP to return these codes.
+.bP
 Not all of these are necessarily supported on any particular terminal.
+.bP
+The naming convention may seem obscure, with some apparent
+misspellings (such as "RSUME" for "resume").
+The names correspond to the long terminfo capability names for the keys,
+and were defined long ago, in the 1980s.
 .PP
 .TS
 center tab(/) ;
@@ -376,6 +398,7 @@ any code using it be conditionalized on the \fBNCURSES_VERSION\fR feature macro.
 \fBcurs_mouse\fR(3X),
 \fBcurs_move\fR(3X),
 \fBcurs_refresh\fR(3X),
+\fBcurs_variables\fR(3X),
 \fBresizeterm\fR(3X).
 .PP
 Comparable functions in the wide-character (ncursesw) library are