ncurses 6.5 - patch 20240504

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

diff --git a/man/curs_inopts.3x b/man/curs_inopts.3x
index 31cf1989864724535dbc63fc783a8e661c93cd2e..63db4967eebc68fd4dbaa04e39668af7ba38dd26 100644 (file)
--- a/man/curs_inopts.3x
+++ b/man/curs_inopts.3x
@@ -1,5 +1,7 @@
+'\" t

 .\"***************************************************************************
 .\"***************************************************************************

-.\" Copyright (c) 1998-2015,2016 Free Software Foundation, Inc.              *
+.\" Copyright 2018-2023,2024 Thomas E. Dickey                                *
+.\" Copyright 1998-2016,2017 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            *
 .\"                                                                          *
 .\" Permission is hereby granted, free of charge, to any person obtaining a  *
 .\" copy of this software and associated documentation files (the            *


@@ -26,322 +28,527 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"

-.\" $Id: curs_inopts.3x,v 1.23 2016/10/22 19:54:35 tom Exp $
-.TH curs_inopts 3X ""
-.ie \n(.g .ds `` \(lq
-.el       .ds `` ``
-.ie \n(.g .ds '' \(rq
-.el       .ds '' ''
-.na
-.hy 0
+.\" $Id: curs_inopts.3x,v 1.66 2024/04/13 22:20:29 tom Exp $
+.TH curs_inopts 3X 2024-04-13 "ncurses @NCURSES_MAJOR@.@NCURSES_MINOR@" "Library calls"
+.ie \n(.g \{\
+.ds `` \(lq
+.ds '' \(rq
+.\}
+.el \{\
+.ie t .ds `` ``
+.el   .ds `` ""
+.ie t .ds '' ''
+.el   .ds '' ""
+.\}

 .SH NAME
 .SH NAME

-\fBcbreak\fR,
-\fBnocbreak\fR,
-\fBecho\fR,
-\fBnoecho\fR,
-\fBhalfdelay\fR,
-\fBintrflush\fR,
-\fBkeypad\fR,
-\fBmeta\fR,
-\fBnodelay\fR,
-\fBnotimeout\fR,
-\fBraw\fR,
-\fBnoraw\fR,
-\fBnoqiflush\fR,
-\fBqiflush\fR,
-\fBtimeout\fR,
-\fBwtimeout\fR,
-\fBtypeahead\fR \- \fBcurses\fR input options
-.ad
-.hy
+\fB\%cbreak\fP,
+\fB\%echo\fP,
+\fB\%halfdelay\fP,
+\fB\%intrflush\fP,
+\fB\%is_cbreak\fP,
+\fB\%is_echo\fP,
+\fB\%is_nl\fP,
+\fB\%is_raw\fP,
+\fB\%keypad\fP,
+\fB\%meta\fP,
+\fB\%nl\fP,
+\fB\%nocbreak\fP,
+\fB\%nodelay\fP,
+\fB\%noecho\fP,
+\fB\%nonl\fP,
+\fB\%noqiflush\fP,
+\fB\%noraw\fP,
+\fB\%notimeout\fP,
+\fB\%qiflush\fP,
+\fB\%raw\fP,
+\fB\%timeout\fP,
+\fB\%wtimeout\fP,
+\fB\%typeahead\fP \-
+get and set \fIcurses\fR terminal input options

 .SH SYNOPSIS
 .SH SYNOPSIS

-\fB#include <curses.h>\fR
+.nf
+\fB#include <curses.h>

 .PP
 .PP

-\fBint cbreak(void);\fR
-.br
-\fBint nocbreak(void);\fR
-.br
-\fBint echo(void);\fR
-.br
-\fBint noecho(void);\fR
-.br
-\fBint halfdelay(int tenths);\fR
-.br
-\fBint intrflush(WINDOW *win, bool bf);\fR
-.br
-\fBint keypad(WINDOW *win, bool bf);\fR
-.br
-\fBint meta(WINDOW *win, bool bf);\fR
-.br
-\fBint nodelay(WINDOW *win, bool bf);\fR
-.br
-\fBint raw(void);\fR
-.br
-\fBint noraw(void);\fR
-.br
-\fBvoid noqiflush(void);\fR
-.br
-\fBvoid qiflush(void);\fR
-.br
-\fBint notimeout(WINDOW *win, bool bf);\fR
-.br
-\fBvoid timeout(int delay);\fR
-.br
-\fBvoid wtimeout(WINDOW *win, int delay);\fR
-.br
-\fBint typeahead(int fd);\fR
-.br
+\fBint cbreak(void);
+\fBint nocbreak(void);
+.PP
+\fBint echo(void);
+\fBint noecho(void);
+.PP
+\fBint intrflush(WINDOW *\fIwin\fP, bool \fIbf\fP);
+\fBint keypad(WINDOW *\fIwin\fP, bool \fIbf\fP);
+\fBint meta(WINDOW *\fIwin\fP, bool \fIbf\fP);
+\fBint nodelay(WINDOW *\fIwin\fP, bool \fIbf\fP);
+\fBint notimeout(WINDOW *\fIwin\fP, bool \fIbf\fP);
+.PP
+\fBint nl(void);
+\fBint nonl(void);
+.PP
+\fBint raw(void);
+\fBint noraw(void);
+.PP
+\fBvoid qiflush(void);
+\fBvoid noqiflush(void);
+.PP
+\fBint halfdelay(int \fItenths\fP);
+\fBvoid timeout(int \fIdelay\fP);
+\fBvoid wtimeout(WINDOW *\fIwin\fP, int \fIdelay\fP);
+.PP
+\fBint typeahead(int \fIfd\fP);
+.PP
+\fI/* extensions */
+\fBint is_cbreak(void);
+\fBint is_echo(void);
+\fBint is_nl(void);
+\fBint is_raw(void);
+.fi

 .SH DESCRIPTION
 .SH DESCRIPTION

-The \fBncurses\fP library provides several functions which let an application
-change the way input from the terminal is handled.
-Some are global, applying to all windows.
+.I \%ncurses
+provides several functions that let an application change the way input
+from the terminal is handled.
+Some are global,
+applying to all windows.

 Others apply only to a specific window.
 Window-specific settings are not automatically applied to new or derived
 windows.
 Others apply only to a specific window.
 Window-specific settings are not automatically applied to new or derived
 windows.

-An application must apply these to each window, if the same behavior
-is needed.
+An application must apply these to each window if the same behavior is
+desired.

 .\"
 .\"

-.SS cbreak
-Normally, the tty driver buffers typed characters until a newline or carriage
+.SS "cbreak, nocbreak"
+Normally,
+the terminal driver buffers typed characters until a newline or carriage

 return is typed.
 return is typed.

-The \fBcbreak\fR routine disables line buffering and
-erase/kill character-processing (interrupt and flow control characters are
-unaffected), making characters typed by the user immediately available to the
+The \fB\%cbreak\fP routine disables line buffering and
+erase/kill character-processing
+(interrupt and flow control characters are unaffected),
+making characters typed by the user immediately available to the

 program.
 program.

-The \fBnocbreak\fR routine returns the terminal to normal (cooked)
+The \fB\%nocbreak\fP routine returns the terminal to normal (cooked)

 mode.
 .PP
 mode.
 .PP

-Initially the terminal may or may not be in \fBcbreak\fR mode, as the mode is
-inherited; therefore, a program should call \fBcbreak\fR or \fBnocbreak\fR
-explicitly.
-Most interactive programs using \fBcurses\fR set the \fBcbreak\fR
-mode.
-Note that \fBcbreak\fR overrides \fBraw\fR.
-[See \fBcurs_getch\fR(3X) for a
-discussion of how these routines interact with \fBecho\fR and \fBnoecho\fR.]
+Initially the terminal may or may not be in \fB\%cbreak\fP mode,
+as the mode is inherited;
+therefore,
+a program should call \fB\%cbreak\fP or \fB\%nocbreak\fP explicitly.
+Most interactive programs using
+.I curses
+set the \fB\%cbreak\fP mode.
+Note that \fB\%cbreak\fP overrides \fBraw\fP.
+[See \fB\%curs_getch\fP(3X) for a discussion of how these routines
+interact with \fBecho\fP and \fB\%noecho\fP.]

 .\"
 .\"

-.SS echo/noecho
-.PP
-The \fBecho\fR and \fBnoecho\fR routines control whether characters typed by
-the user are echoed by \fBgetch\fR as they are typed.
-Echoing by the tty
-driver is always disabled, but initially \fBgetch\fR is in echo mode, so
-characters typed are echoed.
+.SS "echo, noecho"
+The \fBecho\fP and \fB\%noecho\fP routines control whether characters
+typed by the user are echoed by \fB\%getch\fP(3X) as they are typed.
+Echoing by the terminal driver is always disabled,
+but initially \fB\%getch\fP is in echo mode,
+so characters typed are echoed.

 Authors of most interactive programs prefer to do
 Authors of most interactive programs prefer to do

-their own echoing in a controlled area of the screen, or not to echo at all, so
-they disable echoing by calling \fBnoecho\fR.
-[See \fBcurs_getch\fR(3X) for a
-discussion of how these routines interact with \fBcbreak\fR and
-\fBnocbreak\fR.]
+their own echoing in a controlled area of the screen,
+or not to echo at all,
+so they disable echoing by calling \fB\%noecho\fP.
+[See \fB\%curs_getch\fP(3X) for a
+discussion of how these routines interact with \fB\%cbreak\fP and
+\fB\%nocbreak\fP.]

 .\"
 .SS halfdelay
 .\"
 .SS halfdelay

-.PP
-The \fBhalfdelay\fR routine is used for half-delay mode, which is similar to
-\fBcbreak\fR mode in that characters typed by the user are immediately
-available to the program.
-However, after blocking for \fItenths\fR tenths of
-seconds, ERR is returned if nothing has been typed.
-The value of \fItenths\fR
-must be a number between 1 and 255.
-Use \fBnocbreak\fR to leave half-delay
-mode.
+The \fB\%halfdelay\fP routine is used for half-delay mode,
+which is similar to \fB\%cbreak\fP mode in that characters typed by the
+user are immediately available to the program.
+However,
+after blocking for \fItenths\fP tenths of seconds,
+\fBERR\fP is returned if nothing has been typed.
+The value of \fItenths\fP must be a number between 1 and 255.
+Use \fB\%nocbreak\fP to leave half-delay mode.

 .\"
 .SS intrflush
 .\"
 .SS intrflush

-.PP
-If the \fBintrflush\fR option is enabled (\fIbf\fR is \fBTRUE\fR), and an
-interrupt key is pressed on the keyboard (interrupt, break, quit), all output in
-the tty driver queue will be flushed, giving the effect of faster response to
-the interrupt, but causing \fBcurses\fR to have the wrong idea of what is on
-the screen.
-Disabling the option (\fIbf\fR is \fBFALSE\fR) prevents the
-flush.
-The default for the option is inherited from the tty driver settings.
-The window argument is ignored.
+If the \fB\%intrflush\fP option is enabled
+.RI ( bf
+is
+.BR TRUE ),
+and an interrupt key is pressed on the keyboard
+(interrupt,
+break,
+quit),
+all output in the terminal driver queue is flushed,
+giving the effect of faster response to the interrupt,
+but causing
+.I curses
+to have the wrong idea of what is on the screen.
+Disabling the option
+.RI ( bf
+is
+.BR FALSE ),
+prevents the flush.
+The default for the option is inherited from the terminal driver
+settings.
+The
+.I win
+argument is ignored.

 .\"
 .SS keypad
 .\"
 .SS keypad

-.PP
-The \fBkeypad\fR option enables the keypad of the user's terminal.
+The \fB\%keypad\fP option enables the keypad of the user's terminal.

 If
 If

-enabled (\fIbf\fR is \fBTRUE\fR), the user can press a function key
-(such as an arrow key) and \fBwgetch\fR returns a single value
-representing the function key, as in \fBKEY_LEFT\fR.
+enabled
+.RI ( bf
+is
+.BR TRUE ),
+the user can press a function key
+(such as an arrow key)
+and \fB\%wgetch\fP(3X) returns a single value representing the function
+key,
+as in \fB\%KEY_LEFT\fP.

 If disabled
 If disabled

-(\fIbf\fR is \fBFALSE\fR), \fBcurses\fR does not treat function keys
-specially and the program has to interpret the escape sequences
-itself.
-If the keypad in the terminal can be turned on (made to
-transmit) and off (made to work locally), turning on this option
-causes the terminal keypad to be turned on when \fBwgetch\fR is
-called.
+(\fIbf\fP is \fBFALSE\fP),
+.I curses
+does not treat function keys specially and the program has to interpret
+the escape sequences itself.
+If the keypad in the terminal can be turned on
+(made to transmit)
+and off
+(made to work locally),
+turning on this option causes the terminal keypad to be turned on when
+\fB\%wgetch\fP(3X) is called.

 The default value for keypad is \fBFALSE\fP.
 .\"
 .SS meta
 The default value for keypad is \fBFALSE\fP.
 .\"
 .SS meta

-.PP
-Initially, whether the terminal returns 7 or 8 significant bits on
-input depends on the control mode of the tty driver [see termio(7)].
-To force 8 bits to be returned, invoke \fBmeta\fR(\fIwin\fR,
-\fBTRUE\fR); this is equivalent, under POSIX, to setting the CS8 flag
-on the terminal.
-To force 7 bits to be returned, invoke
-\fBmeta\fR(\fIwin\fR, \fBFALSE\fR); this is equivalent, under POSIX,
+Initially,
+whether the terminal returns 7 or 8 significant bits on input depends on
+the control mode of the terminal driver [see \fI\%termios\fP(3)].
+To force 8 bits to be returned,
+invoke
+\fBmeta\fP(\fIwin\fP, \fBTRUE\fP);
+this is equivalent,
+under POSIX,
+to setting the CS8 flag on the terminal.
+To force 7 bits to be returned,
+invoke
+\fBmeta\fP(\fIwin\fP, \fBFALSE\fP);
+this is equivalent,
+under POSIX,

 to setting the CS7 flag on the terminal.
 The window argument,
 to setting the CS7 flag on the terminal.
 The window argument,

-\fIwin\fR, is always ignored.
-If the terminfo capabilities \fBsmm\fR
-(meta_on) and \fBrmm\fR (meta_off) are defined for the terminal,
-\fBsmm\fR is sent to the terminal when \fBmeta\fR(\fIwin\fR,
-\fBTRUE\fR) is called and \fBrmm\fR is sent when \fBmeta\fR(\fIwin\fR,
-\fBFALSE\fR) is called.
+.IR win ,
+is always ignored.
+If the terminfo capabilities
+\fBsmm\fP (meta_on) and
+\fBrmm\fP (meta_off) are defined for the terminal,
+\fBsmm\fP is sent to the terminal when
+\fBmeta\fP(\fIwin\fP, \fBTRUE\fP)
+is called and \fBrmm\fP is sent when
+\fBmeta\fP(\fIwin\fP, \fBFALSE\fP) is called.
+.\"
+.SS "nl, nonl"
+The \fBnl\fP and \fBnonl\fP routines control whether the underlying
+display device translates the return key into newline on input.

 .\"
 .SS nodelay
 .\"
 .SS nodelay

-.PP
-The \fBnodelay\fR option causes \fBgetch\fR to be a non-blocking call.
-If no input is ready, \fBgetch\fR returns \fBERR\fR.
+The \fB\%nodelay\fP option causes \fB\%getch\fP to be a non-blocking
+call.
+If no input is ready,
+\fB\%getch\fP returns \fBERR\fP.

 If disabled
 If disabled

-(\fIbf\fR is \fBFALSE\fR), \fBgetch\fR waits until a key is pressed.
-.PP
-While interpreting an input escape sequence, \fBwgetch\fR sets a timer
+.RI ( bf
+is
+.BR FALSE ),
+\fB\%getch\fP waits until a key is pressed.
+.SS notimeout
+When interpreting an escape sequence,
+\fB\%wgetch\fP(3X) sets a timer

 while waiting for the next character.
 while waiting for the next character.

-If \fBnotimeout(\fR\fIwin\fR,
-\fBTRUE\fR) is called, then \fBwgetch\fR does not set a timer.
-The
-purpose of the timeout is to differentiate between sequences received
-from a function key and those typed by a user.
+If
+\fB\%notimeout(\fIwin\fR, \fBTRUE\fP)
+is called,
+then \fB\%wgetch\fP does not set a timer.
+The purpose of the timeout is to distinguish sequences produced by a
+function key from those typed by a user.

 .\"
 .\"

-.SS raw/noraw
-.PP
-The \fBraw\fR and \fBnoraw\fR routines place the terminal into or out of raw
-mode.
-Raw mode is similar to \fBcbreak\fR mode, in that characters typed are
-immediately passed through to the user program.
-The differences are that in
-raw mode, the interrupt, quit, suspend, and flow control characters are all
-passed through uninterpreted, instead of generating a signal.
-The behavior of
-the BREAK key depends on other bits in the tty driver that are not set by
-\fBcurses\fR.
+.SS "raw, noraw"
+The \fBraw\fP and \fB\%noraw\fP routines place the terminal into or out
+of raw mode.
+Raw mode is similar to \fB\%cbreak\fP mode,
+in that characters typed are immediately passed through to the user
+program.
+The differences are that in raw mode,
+the interrupt,
+quit,
+suspend,
+and flow control characters are all
+passed through uninterpreted,
+instead of generating a signal.
+The behavior of the BREAK key depends on other bits in the terminal
+driver that are not set by
+.IR curses .

 .\"
 .\"

-.SS noqiflush
-.PP
-When the \fBnoqiflush\fR routine is used, normal flush of input and
-output queues associated with the \fBINTR\fR, \fBQUIT\fR and
-\fBSUSP\fR characters will not be done [see termio(7)].
+.SS "qiflush, nqiflush"
+When the \fB\%noqiflush\fP routine is used,
+normal flush of input and output queues associated with the \fBINTR\fP,
+\fBQUIT\fP and \fBSUSP\fP characters will not be done
+[see \fB\%termios\fP(3)].

 When
 When

-\fBqiflush\fR is called, the queues will be flushed when these control
-characters are read.
-You may want to call \fBnoqiflush\fR in a signal
-handler if you want output to continue as though the interrupt
-had not occurred, after the handler exits.
+\fB\%qiflush\fP is called,
+the queues will be flushed when these control characters are read.
+You may want to call \fB\%noqiflush\fP in a signal handler if you want
+output to continue as though the interrupt had not occurred,
+after the handler exits.

 .\"
 .\"

-.SS timeout/wtimeout
-.PP
-The \fBtimeout\fR and \fBwtimeout\fR routines set blocking or
+.SS "timeout, wtimeout"
+The \fB\%timeout\fP and \fB\%wtimeout\fP routines set blocking or

 non-blocking read for a given window.
 non-blocking read for a given window.

-If \fIdelay\fR is negative,
-blocking read is used (i.e., waits indefinitely for
-input).
-If \fIdelay\fR is zero, then non-blocking read is used
-(i.e., read returns \fBERR\fR if no input is waiting).
+If \fIdelay\fP is negative,
+a blocking read is used
+(i.e.,
+waits indefinitely for input).
+If \fIdelay\fP is zero,
+then a non-blocking read is used
+(i.e.,
+.I read
+returns \fBERR\fP if no input is waiting).

 If
 If

-\fIdelay\fR is positive, then read blocks for \fIdelay\fR
-milliseconds, and returns \fBERR\fR if there is still no input.
-Hence, these routines provide the same functionality as \fBnodelay\fR,
+\fIdelay\fP is positive,
+then
+.I read
+blocks for \fIdelay\fP milliseconds,
+and returns \fBERR\fP if there is still no input.
+Hence,
+these routines provide the same functionality as \fB\%nodelay\fP,

 plus the additional capability of being able to block for only
 plus the additional capability of being able to block for only

-\fIdelay\fR milliseconds (where \fIdelay\fR is positive).
+\fIdelay\fP milliseconds
+(where \fIdelay\fP is positive).

 .\"
 .SS typeahead
 .\"
 .SS typeahead

-.PP
-The \fBcurses\fR library does \*(``line-breakout optimization\*(''
-by looking for typeahead periodically while updating the screen.
-If input is found, and it is coming from a tty,
+.I curses
+does \*(``line-breakout optimization\*('' by looking for typeahead
+periodically while updating the screen.
+If input is found,
+and it is coming from a terminal,

 the current update is postponed until
 the current update is postponed until

-\fBrefresh\fR or \fBdoupdate\fR is called again.
+\fB\%refresh\fP(3X) or \fB\%doupdate\fP is called again.

 This allows faster response to commands typed in advance.
 This allows faster response to commands typed in advance.

-Normally, the input FILE
-pointer passed to \fBnewterm\fR, or \fBstdin\fR in the case that
-\fBinitscr\fR was used, will be used to do this typeahead checking.
-The \fBtypeahead\fR routine specifies that the file descriptor
-\fIfd\fR is to be used to check for typeahead instead.
-If \fIfd\fR is
-\-1, then no typeahead checking is done.
+Normally,
+the input
+.I FILE
+pointer passed to \fB\%newterm\fP,
+or \fBstdin\fP in the case that \fB\%initscr\fP was used,
+will be used to do this typeahead checking.
+The \fB\%typeahead\fP routine specifies that the file descriptor
+\fIfd\fP is to be used to check for typeahead instead.
+If \fIfd\fP is
+\-1,
+then no typeahead checking is done.

 .\"
 .SH RETURN VALUE
 .\"
 .SH RETURN VALUE

-All routines that return an integer return \fBERR\fR upon failure and OK (SVr4
-specifies only "an integer value other than \fBERR\fR") upon successful
-completion, unless otherwise noted in the preceding routine descriptions.
+All routines that return an integer return \fBERR\fP upon failure and
+\fBOK\fP
+(SVr4 specifies only \*(``an integer value other than \fBERR\fP\*('')
+upon successful completion,
+unless otherwise noted in the preceding routine descriptions.

 .PP
 .PP

-X/Open does not define any error conditions.
+X/Open Curses does not specify any error conditions.

 In this implementation,
 functions with a window parameter will return an error if it is null.
 In this implementation,
 functions with a window parameter will return an error if it is null.

-Any function will also return an error if the terminal was not initialized.
+Any function will also return an error if the terminal was not
+initialized.

 Also,
 Also,

-.RS
+.RS 3

 .TP 5
 .TP 5

-\fBhalfdelay\fP
+\fB\%halfdelay\fP

 returns an error
 if its parameter is outside the range 1..255.
 .RE
 returns an error
 if its parameter is outside the range 1..255.
 .RE

+.SH NOTES
+\fBecho\fP,
+\fB\%noecho\fP,
+\fB\%halfdelay\fP,
+\fB\%intrflush\fP,
+\fBmeta\fP,
+\fBnl\fP,
+\fBnonl\fP,
+\fB\%nodelay\fP,
+\fB\%notimeout\fP,
+\fB\%noqiflush\fP,
+\fB\%qiflush\fP,
+\fB\%timeout\fP,
+and
+\fB\%wtimeout\fP
+may be implemented as macros.
+.PP
+\fB\%noraw\fP and \fB\%nocbreak\fP follow historical practice in that
+they attempt to restore normal (\*(``cooked\*('') mode
+from raw and cbreak modes respectively.
+Mixing \fBraw\fP/\fB\%noraw\fP and \fB\%cbreak\fP/\fB\%nocbreak\fP calls
+leads to terminal driver control states that are hard to predict or
+understand;
+doing so is not recommended.
+.SH EXTENSIONS
+.I \%ncurses
+provides four \*(``is_\*('' functions that may be used to detect if the
+corresponding flags were set or reset.
+.PP
+.TS
+center;
+Lb Lb Lb
+L  L  L .
+Query  Set     Reset
+_
+is_cbreak      cbreak  nocbreak
+is_echo        echo    noecho
+is_nl  nl      nonl
+is_raw raw     noraw
+.TE
+.PP
+In each case,
+the function returns
+.TP 4 \" "-1" + 2n
+1
+if the flag is set,
+.TP
+0
+if the flag is reset,
+or
+.TP
+\-1
+if the library is not initialized.
+.PP
+They were designed for
+\fB\%ncurses\fP(3X),
+and are not found in SVr4
+.IR curses ,
+4.4BSD
+.IR curses ,
+or any other previous
+.I curses
+implementation.

 .SH PORTABILITY
 .SH PORTABILITY

-These functions are described in the XSI Curses standard, Issue 4.
+Applications employing
+.I \%ncurses
+extensions should condition their use on the visibility of the
+.B \%NCURSES_VERSION
+preprocessor macro.

 .PP
 .PP

-The ncurses library obeys the XPG4 standard and the historical practice of the
-AT&T curses implementations, in that the echo bit is cleared when curses
+Except as noted in section \*(``EXTENSIONS\*('' above,
+X/Open Curses, Issue 4, Version 2 describes these functions.
+.PP
+.I \%ncurses
+follows X/Open Curses
+and the historical practice of AT&T
+.I curses
+implementations,
+in that the echo bit is cleared when
+.I curses

 initializes the terminal state.
 initializes the terminal state.

-BSD curses differed from this slightly; it
-left the echo bit on at initialization, but the BSD \fBraw\fR call turned it
-off as a side-effect.
-For best portability, set echo or noecho explicitly
-just after initialization, even if your program remains in cooked mode.
+BSD
+.I curses
+differed from this slightly;
+it left the echo bit on at initialization,
+but the BSD \fBraw\fP call turned it off as a side effect.
+For best portability,
+set \fBecho\fP or \fB\%noecho\fP explicitly just after initialization,
+even if your program remains in cooked mode.
+.PP
+X/Open Curses is ambiguous regarding whether \fBraw\fP should disable
+the CR/LF translations controlled by \fBnl\fP and \fBnonl\fP.
+BSD
+.I curses
+did turn off these translations;
+AT&T
+.I curses
+(at least as late as SVr1)
+did not.
+.I \%ncurses
+does so,
+on the assumption that a programmer requesting raw input wants a clean
+(ideally,
+8-bit clean)
+connection that the operating system will not alter.

 .PP
 .PP

-When \fBkeypad\fP is first enabled,
-ncurses loads the key-definitions for the current terminal description.
+When \fB\%keypad\fP is first enabled,
+.I \%ncurses
+loads the key definitions for the current terminal description.

 If the terminal description includes extended string capabilities,
 If the terminal description includes extended string capabilities,

-e.g., from using the \fB\-x\fP option of \fB@TIC@\fP,
-then ncurses also defines keys for the capabilities whose names
-begin with "k".
-The corresponding keycodes are generated and (depending on previous
-loads of terminal descriptions) may differ from one execution of a
-program to the next.
-The generated keycodes are recognized by the \fBkeyname\fP function
-(which will then return a name beginning with "k" denoting the
-terminfo capability name rather than "K", used for curses key-names).
-On the other hand, an application can use \fBdefine_key\fP to establish
+e.g.,
+from using the
+.B \-x
+option of \fB\%@TIC@\fP,
+then
+.I \%ncurses
+also defines keys for the capabilities whose names begin with
+\*(``k\*(''.
+The corresponding keycodes are generated and
+(depending on previous loads of terminal descriptions)
+may differ from one execution of a program to the next.
+The generated keycodes are recognized by the \fB\%keyname\fP(3X)
+function
+(which will then return a name beginning with \*(``k\*('' denoting the
+terminfo capability name rather than \*(``K\*('',
+used for
+.I curses
+key names).
+On the other hand,
+an application can use \fB\%define_key\fP(3X) to establish

 a specific keycode for a given string.
 This makes it possible for an application to check for an extended
 a specific keycode for a given string.
 This makes it possible for an application to check for an extended

-capability's presence with \fBtigetstr\fP,
+capability's presence with \fB\%tigetstr\fP,

 and reassign the keycode to match its own needs.
 .PP
 and reassign the keycode to match its own needs.
 .PP

-Low-level applications can use \fBtigetstr\fP to obtain the definition
+Low-level applications can use \fB\%tigetstr\fP to obtain the definition

 of any particular string capability.
 of any particular string capability.

-Higher-level applications which use the curses \fBwgetch\fP
-and similar functions to return keycodes rely upon the order in which
-the strings are loaded.
+Higher-level applications which use the
+.I curses
+\fB\%wgetch\fP and similar functions to return keycodes rely upon the
+order in which the strings are loaded.

 If more than one key definition has the same string value,
 If more than one key definition has the same string value,

-then \fBwgetch\fP can return only one keycode.
-Most curses implementations (including ncurses)
+then \fB\%wgetch\fP can return only one keycode.
+Most
+.I curses
+implementations
+(including
+.IR \%ncurses )

 load key definitions in the order
 defined by the array of string capability names.
 The last key to be loaded determines the keycode which will be returned.
 load key definitions in the order
 defined by the array of string capability names.
 The last key to be loaded determines the keycode which will be returned.

-In ncurses, you may also have extended capabilities interpreted as
-key definitions.
+In
+.IR \%ncurses ,
+you may also have extended capabilities interpreted as key definitions.

 These are loaded after the predefined keys,
 and if a capability's value is the same as a previously-loaded
 key definition,
 the later definition is the one used.
 These are loaded after the predefined keys,
 and if a capability's value is the same as a previously-loaded
 key definition,
 the later definition is the one used.

-.SH NOTES
-Note that \fBecho\fR, \fBnoecho\fR, \fBhalfdelay\fR, \fBintrflush\fR,
-\fBmeta\fR, \fBnodelay\fR, \fBnotimeout\fR, \fBnoqiflush\fR,
-\fBqiflush\fR, \fBtimeout\fR, and \fBwtimeout\fR may be macros.
-.PP
-The \fBnoraw\fR and \fBnocbreak\fR calls follow historical practice in that
-they attempt to restore to normal (`cooked') mode from raw and cbreak modes
-respectively.
-Mixing raw/noraw and cbreak/nocbreak calls leads to tty driver
-control states that are hard to predict or understand; it is not recommended.
+.SH HISTORY
+Formerly,
+.I \%ncurses
+used
+.B \%nl
+and
+.B \%nonl
+to control the conversion of newlines to carriage return/line feed
+on output as well as input.
+X/Open Curses documents the use of these functions only for input.
+This difference arose from converting the
+.I \%pcurses
+source (1986),
+which used
+\fI\%ioctl\fP(2) calls and the
+.I \%sgttyb
+structure,
+to
+.I \%termios
+(the POSIX terminal API).
+In the former,
+both input and output were controlled via a single option
+.BR \%CRMOD ,
+while the latter separates these features.
+Because that conversion interferes with output optimization,
+.I \%ncurses
+6.2 (2020) amended
+.B \%nl
+and
+.B \%nonl
+to eliminate their effect on output.

 .SH SEE ALSO
 .SH SEE ALSO

-\fBcurses\fR(3X),
-\fBcurs_getch\fR(3X),
-\fBcurs_initscr\fR(3X),
-\fBcurs_util\fR(3X),
-\fBdefine_key\fR(3X),
-\fBtermio\fR(7)
+\fB\%curses\fP(3X),
+\fB\%curs_getch\fP(3X),
+\fB\%curs_initscr\fP(3X),
+\fB\%curs_util\fP(3X),
+\fB\%define_key\fP(3X),
+\fB\%termios\fP(3)