ncurses 6.5 - patch 20240525

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

diff --git a/man/curs_kernel.3x b/man/curs_kernel.3x
index fba3dd8d7f901eb9a210fd1752fa680b69987f42..8c4119de66e915dc9673d28b72f9f33583916c58 100644 (file)
--- a/man/curs_kernel.3x
+++ b/man/curs_kernel.3x
@@ -1,5 +1,5 @@
 .\"***************************************************************************
 .\"***************************************************************************

-.\" Copyright 2018-2021,2022 Thomas E. Dickey                                *
+.\" 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  *
 .\" Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
 .\"                                                                          *
 .\" Permission is hereby granted, free of charge, to any person obtaining a  *


@@ -27,87 +27,85 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"

-.\" $Id: curs_kernel.3x,v 1.33 2022/02/12 20:05:11 tom Exp $
-.ie \n(.g .ds `` \(lq
-.el       .ds `` ``
-.ie \n(.g .ds '' \(rq
-.el       .ds '' ''
+.\" $Id: curs_kernel.3x,v 1.63 2024/05/25 21:13:56 tom Exp $
+.TH curs_kernel 3X 2024-05-25 "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 '' ""
+.\}
+.

 .de bP
 .ie n  .IP \(bu 4
 .el    .IP \(bu 2
 ..
 .de bP
 .ie n  .IP \(bu 4
 .el    .IP \(bu 2
 ..

-.TH curs_kernel 3X 2022-02-12 "ncurses 6.4" "Library calls"
-.na
-.hy 0

 .SH NAME
 .SH NAME

-\fBdef_prog_mode\fP,
-\fBdef_shell_mode\fP,
-\fBreset_prog_mode\fP,
-\fBreset_shell_mode\fP,
-\fBresetty\fP,
-\fBsavetty\fP,
-\fBgetsyx\fP,
-\fBsetsyx\fP,
-\fBripoffline\fP,
-\fBcurs_set\fP,
-\fBnapms\fP \- low-level \fBcurses\fP routines
-.ad
-.hy
+\fB\%def_prog_mode\fP,
+\fB\%def_shell_mode\fP,
+\fB\%reset_prog_mode\fP,
+\fB\%reset_shell_mode\fP,
+\fB\%resetty\fP,
+\fB\%savetty\fP,
+\fB\%getsyx\fP,
+\fB\%setsyx\fP,
+\fB\%curs_set\fP,
+\fB\%mvcur\fP,
+\fB\%napms\fP,
+\fB\%ripoffline\fP \-
+low-level \fIcurses\fR routines

 .SH SYNOPSIS
 .SH SYNOPSIS

-\fB#include <curses.h>\fP
-.sp
-\fBint def_prog_mode(void);\fP
-.br
-\fBint def_shell_mode(void);\fP
-.sp
-\fBint reset_prog_mode(void);\fP
-.br
-\fBint reset_shell_mode(void);\fP
-.sp
-\fBint resetty(void);\fP
-.br
-\fBint savetty(void);\fP
-.sp
-\fBvoid getsyx(int \fIy\fB, int \fIx\fB);\fR
-.br
-\fBvoid setsyx(int \fIy\fB, int \fIx\fB);\fR
-.sp
-\fBint ripoffline(int \fIline\fB, int (*\fIinit\fB)(WINDOW *, int));\fR
-.br
-\fBint curs_set(int \fIvisibility\fB);\fR
-.br
-\fBint napms(int \fIms\fB);\fR
-.br
+.nf
+\fB#include <curses.h>
+.PP
+\fBint def_prog_mode(void);
+\fBint def_shell_mode(void);
+.PP
+\fBint reset_prog_mode(void);
+\fBint reset_shell_mode(void);
+.PP
+\fBint resetty(void);
+\fBint savetty(void);
+.PP
+\fBvoid getsyx(int \fIy\fP, int \fIx\fP);
+\fBvoid setsyx(int \fIy\fP, int \fIx\fP);
+.PP
+\fBint curs_set(int \fIvisibility\fP);
+\fBint mvcur(int \fIoldrow\fP, int \fIoldcol\fP, int \fInewrow\fP, int \fInewcol\fP);
+\fBint napms(int \fIms\fP);
+\fBint ripoffline(int \fIline\fP, int (*\fIinit\fP)(WINDOW *, int));
+.fi

 .SH DESCRIPTION
 The following routines give low-level access
 to various \fBcurses\fP capabilities.
 These routines typically are used inside library routines.
 .SH DESCRIPTION
 The following routines give low-level access
 to various \fBcurses\fP capabilities.
 These routines typically are used inside library routines.

-.SS def_prog_mode, def_shell_mode
-.PP
+.SS "def_prog_mode, def_shell_mode"

 The \fBdef_prog_mode\fP and \fBdef_shell_mode\fP routines save the
 The \fBdef_prog_mode\fP and \fBdef_shell_mode\fP routines save the

-current terminal modes as the \*(``program\*('' (in \fBcurses\fP) or \*(``shell\*(''
+current terminal modes as the \*(``program\*(''
+(in \fBcurses\fP) or \*(``shell\*(''

 (not in \fBcurses\fP) state for use by the \fBreset_prog_mode\fP and
 \fBreset_shell_mode\fP routines.
 This is done automatically by \fBinitscr\fP.
 There is one such save area for each screen context
 allocated by \fBnewterm\fP.
 (not in \fBcurses\fP) state for use by the \fBreset_prog_mode\fP and
 \fBreset_shell_mode\fP routines.
 This is done automatically by \fBinitscr\fP.
 There is one such save area for each screen context
 allocated by \fBnewterm\fP.

-.SS reset_prog_mode, reset_shell_mode
-.PP
+.SS "reset_prog_mode, reset_shell_mode"

 The \fBreset_prog_mode\fP and \fBreset_shell_mode\fP routines restore
 the terminal to \*(``program\*('' (in \fBcurses\fP) or \*(``shell\*('' (out of
 \fBcurses\fP) state.
 These are done automatically by \fBendwin\fP(3X) and,
 after an \fBendwin\fP, by \fBdoupdate\fP,
 so they normally are not called.
 The \fBreset_prog_mode\fP and \fBreset_shell_mode\fP routines restore
 the terminal to \*(``program\*('' (in \fBcurses\fP) or \*(``shell\*('' (out of
 \fBcurses\fP) state.
 These are done automatically by \fBendwin\fP(3X) and,
 after an \fBendwin\fP, by \fBdoupdate\fP,
 so they normally are not called.

-.SS resetty, savetty
-.PP
+.SS "resetty, savetty"

 The \fBresetty\fP and \fBsavetty\fP routines save and restore the
 state of the terminal modes.
 \fBsavetty\fP saves the current state in
 a buffer and \fBresetty\fP restores the state to what it was at the
 last call to \fBsavetty\fP.
 .SS getsyx
 The \fBresetty\fP and \fBsavetty\fP routines save and restore the
 state of the terminal modes.
 \fBsavetty\fP saves the current state in
 a buffer and \fBresetty\fP restores the state to what it was at the
 last call to \fBsavetty\fP.
 .SS getsyx

-.PP

 The \fBgetsyx\fP routine returns the current coordinates
 of the \fIvirtual screen\fP cursor in \fIy\fP and \fIx\fP.
 If \fBleaveok\fP is currently \fBTRUE\fP, then
 The \fBgetsyx\fP routine returns the current coordinates
 of the \fIvirtual screen\fP cursor in \fIy\fP and \fIx\fP.
 If \fBleaveok\fP is currently \fBTRUE\fP, then


@@ -120,7 +118,6 @@ therefore, \fIy\fP and \fIx\fP should be used only as arguments for
 Few applications will use this feature,
 most use \fBgetyx\fP instead.
 .SS setsyx
 Few applications will use this feature,
 most use \fBgetyx\fP instead.
 .SS setsyx

-.PP

 The \fBsetsyx\fP routine sets
 the \fIvirtual screen\fP cursor to \fIy\fP, \fIx\fP.
 If \fIy\fP and \fIx\fP are both \fB\-1\fP, then
 The \fBsetsyx\fP routine sets
 the \fIvirtual screen\fP cursor to \fIy\fP, \fIx\fP.
 If \fIy\fP and \fIx\fP are both \fB\-1\fP, then


@@ -136,12 +133,60 @@ at the beginning, do its manipulation of its own windows, do a
 .PP
 Few applications will use this feature,
 most use \fBwmove\fP instead.
 .PP
 Few applications will use this feature,
 most use \fBwmove\fP instead.

-.SS ripoffline
+.SS curs_set
+The \fBcurs_set\fP routine sets the cursor state to invisible,
+normal, or very visible for \fBvisibility\fP equal to \fB0\fP,
+\fB1\fP, or \fB2\fP respectively.
+If the terminal supports the \fIvisibility\fP requested,
+the previous \fIcursor\fP state is returned;
+otherwise, \fBERR\fP is returned.
+.SS mvcur
+.B \%mvcur
+provides low-level cursor motion.
+It takes effect immediately,
+rather than at the next refresh.
+Unlike the other low-level output functions,
+which either write to the standard output stream
+or are passed a function pointer to perform output,
+.B \%mvcur
+uses a file descriptor derived from the output stream parameter of
+\fB\%newterm\fP(3X).

 .PP
 .PP

-The \fBripoffline\fP routine provides access to the same facility that
-\fBslk_init\fP [see \fBcurs_slk\fP(3X)] uses to reduce the size of the
-screen.
-\fBripoffline\fP must be called before \fBinitscr\fP or
+One application of
+.B \%mvcur
+accompanies the temporary use of another program to write to the
+terminal screen.
+For example,
+first call \fB\%refresh\fP(3X) to ensure that the screen and the
+library's model of it is up to date;
+then call
+.BR \%reset_shell_mode ";"
+write to the screen with the external application;
+call
+.BR \%reset_prog_mode ";"
+and finally call
+.B \%mvcur
+to set the cursor's location to where
+.I \%curses
+thinks it is,
+since the library has no knowledge of how the external application
+moved it.
+.\" https://lists.gnu.org/archive/html/bug-ncurses/2016-10/msg00002.html
+.SS napms
+.B \%napms
+sleeps for
+.I ms
+milliseconds.
+If
+.I ms
+exceeds 30,000
+(thirty seconds),
+it is capped at that value.
+.SS ripoffline
+.B \%ripoffline
+provides access to the same facility that \fB\%slk_init\fP(3X) uses to
+reduce the size of the screen.
+\fB\%ripoffline\fP must be called before \fBinitscr\fP or

 \fBnewterm\fP is called, to prepare these initial actions:
 .bP
 If \fIline\fP is positive, a line is removed from the top of \fBstdscr\fP.
 \fBnewterm\fP is called, to prepare these initial actions:
 .bP
 If \fIline\fP is positive, a line is removed from the top of \fBstdscr\fP.


@@ -164,17 +209,6 @@ It is allowable to call \fBwnoutrefresh\fP during the initialization routine.
 .PP
 \fBripoffline\fP can be called up to five times before calling \fBinitscr\fP or
 \fBnewterm\fP.
 .PP
 \fBripoffline\fP can be called up to five times before calling \fBinitscr\fP or
 \fBnewterm\fP.

-.SS curs_set
-.PP
-The \fBcurs_set\fP routine sets the cursor state to invisible,
-normal, or very visible for \fBvisibility\fP equal to \fB0\fP,
-\fB1\fP, or \fB2\fP respectively.
-If the terminal supports the \fIvisibility\fP requested,
-the previous \fIcursor\fP state is returned;
-otherwise, \fBERR\fP is returned.
-.SS napms
-.PP
-The \fBnapms\fP routine is used to sleep for \fIms\fP milliseconds.

 .SH RETURN VALUE
 Except for \fBcurs_set\fP, these routines always return \fBOK\fP.
 .PP
 .SH RETURN VALUE
 Except for \fBcurs_set\fP, these routines always return \fBOK\fP.
 .PP


@@ -185,18 +219,17 @@ requested \fIvisibility\fP is not supported.
 X/Open defines no error conditions.
 In this implementation
 .TP 5
 X/Open defines no error conditions.
 In this implementation
 .TP 5

-.na
-.hy 0

 \fBdef_prog_mode\fP, \fBdef_shell_mode\fP, \fBreset_prog_mode\fP, \fBreset_shell_mode\fP
 \fBdef_prog_mode\fP, \fBdef_shell_mode\fP, \fBreset_prog_mode\fP, \fBreset_shell_mode\fP

-.hy
-.ad
-return an error
+return
+.B ERR

 if the terminal was not initialized, or
 if the I/O call to obtain the terminal settings fails.
 .TP 5
 \fBripoffline\fP
 if the terminal was not initialized, or
 if the I/O call to obtain the terminal settings fails.
 .TP 5
 \fBripoffline\fP

-returns an error if the maximum number of ripped-off lines
-exceeds the maximum (NRIPS = 5).
+returns
+.B ERR
+if the maximum number of ripped-off lines
+exceeds the maximum (5).

 .SH NOTES
 Note that \fBgetsyx\fP is a macro, so \fB&\fP is not necessary before
 the variables \fIy\fP and \fIx\fP.
 .SH NOTES
 Note that \fBgetsyx\fP is a macro, so \fB&\fP is not necessary before
 the variables \fIy\fP and \fIx\fP.


@@ -206,26 +239,72 @@ of \fBcurs_set\fP \*(``is currently incorrect\*(''.
 This implementation gets it right, but it may be unwise to count
 on the correctness of the return value anywhere else.
 .PP
 This implementation gets it right, but it may be unwise to count
 on the correctness of the return value anywhere else.
 .PP

-Both ncurses and SVr4 will call \fBcurs_set\fP in \fBendwin\fP
+Both \fI\%ncurses\fP and SVr4 will call \fBcurs_set\fP in \fBendwin\fP

 if \fBcurs_set\fP
 has been called to make the cursor other than normal, i.e., either
 invisible or very visible.
 if \fBcurs_set\fP
 has been called to make the cursor other than normal, i.e., either
 invisible or very visible.

-There is no way for ncurses to determine the initial cursor state to
-restore that.
+There is no way for \fI\%ncurses\fP to determine the initial cursor
+state to restore that.
+.SH EXTENSIONS
+In
+.IR \%ncurses ","
+.B \%mvcur
+accepts
+.B \-1
+for either or both old coordinates.
+This value tells
+.I \%ncurses
+that the old location is unknown,
+and that it must use only absolute motion,
+as with the
+.B \%cursor_address
+.RB ( cup )
+capability,
+rather than the least costly combination of absolute and relative
+motion.

 .SH PORTABILITY
 The \fIvirtual screen\fP functions \fBsetsyx\fP and \fBgetsyx\fP
 .SH PORTABILITY
 The \fIvirtual screen\fP functions \fBsetsyx\fP and \fBgetsyx\fP

-are not described in the XSI Curses standard, Issue 4.
-All other functions are as described in XSI Curses.
+are not described in X/Open Curses, Issue 4.
+All other functions are as described in X/Open Curses.

 .PP
 The SVr4 documentation describes \fBsetsyx\fP and \fBgetsyx\fP
 as having return type int.
 This is misleading, as they are macros with no documented semantics
 for the return value.
 .PP
 The SVr4 documentation describes \fBsetsyx\fP and \fBgetsyx\fP
 as having return type int.
 This is misleading, as they are macros with no documented semantics
 for the return value.

+.PP
+X/Open Curses notes:
+.RS
+.PP
+\*(``After use of
+.IR \%mvcur "(),"
+the model Curses maintains of the state of the terminal might not
+match the actual state of the terminal.
+An application should touch and refresh the window before
+resuming conventional use of Curses.\*(''
+.RE
+.PP
+Both
+.I \%ncurses
+and SVr4
+.I curses
+implement
+.B \%mvcur
+using the
+.I SCREEN
+data allocated in either \fB\%initscr\fP(3X) or \fB\%newterm\fP(3X).
+X/Open Curses states that the old location must be given for
+.B \%mvcur
+to accommodate terminals that lack absolute cursor positioning.
+.\" X/Open Curses Issue 7, p. 161
+.PP
+If interrupted, \fI\%ncurses\fP restarts \fBnapms\fP.
+That, and the limitation to 30 seconds,
+are different from other implementations.

 .SH SEE ALSO
 .SH SEE ALSO

-\fBcurses\fP(3X),
-\fBcurs_initscr\fP(3X),
-\fBcurs_outopts\fP(3X),
-\fBcurs_refresh\fP(3X),
-\fBcurs_scr_dump\fP(3X),
-\fBcurs_slk\fP(3X),
-\fBcurs_variables\fP(3X).
+\fB\%curses\fP(3X),
+\fB\%curs_initscr\fP(3X),
+\fB\%curs_outopts\fP(3X),
+\fB\%curs_refresh\fP(3X),
+\fB\%curs_scr_dump\fP(3X),
+\fB\%curs_slk\fP(3X),
+\fB\%curs_variables\fP(3X)