ncurses 6.3 - patch 20220724

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

diff --git a/man/curs_initscr.3x b/man/curs_initscr.3x
index dc15ecbca87bd20467d4588e51b37a64e7c8c481..5e17ead0a659bd23838095397ea0e3b03bb0a443 100644 (file)
--- a/man/curs_initscr.3x
+++ b/man/curs_initscr.3x
@@ -1,5 +1,6 @@
 .\"***************************************************************************
 .\"***************************************************************************

-.\" Copyright (c) 1998-2014,2015 Free Software Foundation, Inc.              *
+.\" Copyright 2018-2021,2022 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            *


@@ -26,10 +27,11 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"

-.\" $Id: curs_initscr.3x,v 1.24 2015/07/21 23:01:38 tom Exp $
+.\" $Id: curs_initscr.3x,v 1.39 2022/07/24 15:46:49 tom Exp $

 .TH curs_initscr 3X ""
 .de bP
 .TH curs_initscr 3X ""
 .de bP

-.IP \(bu 4
+.ie n  .IP \(bu 4
+.el    .IP \(bu 2

 ..
 .ie \n(.g .ds `` \(lq
 .el       .ds `` ``
 ..
 .ie \n(.g .ds `` \(lq
 .el       .ds `` ``


@@ -38,109 +40,115 @@
 .na
 .hy 0
 .SH NAME
 .na
 .hy 0
 .SH NAME

-\fBinitscr\fR,
-\fBnewterm\fR,
-\fBendwin\fR,
-\fBisendwin\fR,
-\fBset_term\fR,
-\fBdelscreen\fR \- \fBcurses\fR screen initialization and manipulation routines
+\fBinitscr\fP,
+\fBnewterm\fP,
+\fBendwin\fP,
+\fBisendwin\fP,
+\fBset_term\fP,
+\fBdelscreen\fP \- \fBcurses\fP screen initialization and manipulation routines

 .ad
 .hy
 .SH SYNOPSIS
 .ad
 .hy
 .SH SYNOPSIS

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

 .sp
 .sp

-\fBWINDOW *initscr(void);\fR
+\fBWINDOW *initscr(void);\fP

 .br
 .br

-\fBint endwin(void);\fR
-.br
-\fBbool isendwin(void);\fR
-.br
-\fBSCREEN *newterm(char *\fP\fItype\fP\fB, FILE *\fP\fIoutfd\fP\fB, FILE *\fP\fIinfd\fP\fB);\fR
+\fBint endwin(void);\fP
+.sp
+\fBbool isendwin(void);\fP
+.sp
+\fBSCREEN *newterm(const char *\fItype\fB, FILE *\fIoutfd\fB, FILE *\fIinfd\fB);\fR

 .br
 .br

-\fBSCREEN *set_term(SCREEN *\fP\fInew\fP\fB);\fR
+\fBSCREEN *set_term(SCREEN *\fInew\fB);\fR

 .br
 .br

-\fBvoid delscreen(SCREEN* \fP\fIsp\fP\fB);\fR
+\fBvoid delscreen(SCREEN* \fIsp\fB);\fR

 .br
 .SH DESCRIPTION
 .SS initscr
 .br
 .SH DESCRIPTION
 .SS initscr

-\fBinitscr\fR is normally the first \fBcurses\fR routine to call when
+\fBinitscr\fP is normally the first \fBcurses\fP routine to call when

 initializing a program.
 A few special routines sometimes need to be called before it;
 initializing a program.
 A few special routines sometimes need to be called before it;

-these are \fBslk_init\fR, \fBfilter\fR, \fBripoffline\fR,
-\fBuse_env\fR.
+these are \fBslk_init\fP(3X), \fBfilter\fP, \fBripoffline\fP,
+\fBuse_env\fP.

 For multiple-terminal applications,
 For multiple-terminal applications,

-\fBnewterm\fR may be called before \fBinitscr\fR.
+\fBnewterm\fP may be called before \fBinitscr\fP.

 .PP
 .PP

-The initscr code determines the terminal type and initializes all \fBcurses\fR
+The initscr code determines the terminal type and initializes all \fBcurses\fP

 data structures.
 data structures.

-\fBinitscr\fR also causes the first call to \fBrefresh\fR to clear the screen.
-If errors occur, \fBinitscr\fR writes an appropriate error
+\fBinitscr\fP also causes the first call to \fBrefresh\fP(3X)
+to clear the screen.
+If errors occur, \fBinitscr\fP writes an appropriate error

 message to standard error and exits;
 message to standard error and exits;

-otherwise, a pointer is returned to \fBstdscr\fR.
+otherwise, a pointer is returned to \fBstdscr\fP.

 .SS newterm
 .PP
 .SS newterm
 .PP

-A program that outputs to more than one terminal should use the \fBnewterm\fR
-routine for each terminal instead of \fBinitscr\fR.
+A program that outputs to more than one terminal should use the \fBnewterm\fP
+routine for each terminal instead of \fBinitscr\fP.

 A program that needs to inspect capabilities,
 so it can continue to run in a line-oriented mode if the
 terminal cannot support a screen-oriented program, would also use
 A program that needs to inspect capabilities,
 so it can continue to run in a line-oriented mode if the
 terminal cannot support a screen-oriented program, would also use

-\fBnewterm\fR.
-The routine \fBnewterm\fR should be called once for each terminal.
-It returns a variable of type \fBSCREEN *\fR which should be saved
+\fBnewterm\fP.
+The routine \fBnewterm\fP should be called once for each terminal.
+It returns a variable of type \fBSCREEN *\fP which should be saved

 as a reference to that terminal.
 \fBnewterm\fP's arguments are
 .bP
 as a reference to that terminal.
 \fBnewterm\fP's arguments are
 .bP

-the \fItype\fR of the terminal to be used in place of \fB$TERM\fR,
+the \fItype\fP of the terminal to be used in place of \fB$TERM\fP,

 .bP
 a file pointer for output to the terminal, and
 .bP
 another file pointer for input from the terminal
 .PP
 .bP
 a file pointer for output to the terminal, and
 .bP
 another file pointer for input from the terminal
 .PP

-If the \fItype\fR parameter is \fBNULL\fR, \fB$TERM\fR will be used.
+If the \fItype\fP parameter is \fBNULL\fP, \fB$TERM\fP will be used.

 .SS endwin
 .PP
 The program must also call
 .SS endwin
 .PP
 The program must also call

-\fBendwin\fR for each terminal being used before exiting from \fBcurses\fR.
-If \fBnewterm\fR is called more than once for the same terminal, the first
-terminal referred to must be the last one for which \fBendwin\fR is called.
+\fBendwin\fP for each terminal being used before exiting from \fBcurses\fP.
+If \fBnewterm\fP is called more than once for the same terminal, the first
+terminal referred to must be the last one for which \fBendwin\fP is called.

 .PP
 .PP

-A program should always call \fBendwin\fR before exiting or escaping from
-\fBcurses\fR mode temporarily.
+A program should always call \fBendwin\fP before exiting or escaping from
+\fBcurses\fP mode temporarily.

 This routine
 .bP
 This routine
 .bP

-restores tty modes,
+resets colors to correspond with the default color pair 0,

 .bP
 .bP

-moves the cursor to the lower left-hand corner of the screen and
+moves the cursor to the lower left-hand corner of the screen,

 .bP
 .bP

-resets the terminal into
-the proper non-visual mode.
+clears the remainder of the line so that it uses the default colors,
+.bP
+sets the cursor to normal visibility (see \fBcurs_set\fP(3X)),
+.bP
+stops cursor-addressing mode using the \fIexit_ca_mode\fP terminal capability,
+.bP
+restores tty modes (see \fBreset_shell_mode\fP(3X)).

 .PP
 .PP

-Calling \fBrefresh\fR or \fBdoupdate\fR after a
+Calling \fBrefresh\fP(3X) or \fBdoupdate\fP(3X) after a

 temporary escape causes the program to resume visual mode.
 .SS isendwin
 .PP
 temporary escape causes the program to resume visual mode.
 .SS isendwin
 .PP

-The \fBisendwin\fR routine returns \fBTRUE\fR if \fBendwin\fR has been
-called without any subsequent calls to \fBwrefresh\fR,
-and \fBFALSE\fR otherwise.
+The \fBisendwin\fP routine returns \fBTRUE\fP if \fBendwin\fP has been
+called without any subsequent calls to \fBwrefresh\fP,
+and \fBFALSE\fP otherwise.

 .SS set_term
 .PP
 .SS set_term
 .PP

-The \fBset_term\fR routine is used to switch between different terminals.
-The screen reference \fBnew\fR becomes the new current terminal.
+The \fBset_term\fP routine is used to switch between different terminals.
+The screen reference \fInew\fP becomes the new current terminal.

 The previous terminal is returned by the routine.
 The previous terminal is returned by the routine.

-This is the only routine which manipulates \fBSCREEN\fR pointers;
+This is the only routine which manipulates \fBSCREEN\fP pointers;

 all other routines affect only the current terminal.
 .SS delscreen
 .PP
 all other routines affect only the current terminal.
 .SS delscreen
 .PP

-The \fBdelscreen\fR routine frees storage associated with the
-\fBSCREEN\fR data structure.
-The \fBendwin\fR routine does not do
-this, so \fBdelscreen\fR should be called after \fBendwin\fR if a
-particular \fBSCREEN\fR is no longer needed.
+The \fBdelscreen\fP routine frees storage associated with the
+\fBSCREEN\fP data structure.
+The \fBendwin\fP routine does not do
+this, so \fBdelscreen\fP should be called after \fBendwin\fP if a
+particular \fBSCREEN\fP is no longer needed.

 .SH RETURN VALUE
 .SH RETURN VALUE

-\fBendwin\fR returns the integer \fBERR\fR upon failure and \fBOK\fR
+\fBendwin\fP returns the integer \fBERR\fP upon failure and \fBOK\fP

 upon successful completion.
 .PP
 upon successful completion.
 .PP

-Routines that return pointers always return \fBNULL\fR on error.
+Routines that return pointers always return \fBNULL\fP on error.

 .PP
 X/Open defines no error conditions.
 In this implementation
 .PP
 X/Open defines no error conditions.
 In this implementation


@@ -155,48 +163,78 @@ i.e.,
 .bP
 \fBset_term\fP
 returns no error.
 .bP
 \fBset_term\fP
 returns no error.

-.SH NOTES
-Note that \fBinitscr\fR and \fBnewterm\fR may be macros.

 .SH PORTABILITY
 These functions were described in the XSI Curses standard, Issue 4.
 As of 2015, the current document is X/Open Curses, Issue 7.
 .SS Differences
 X/Open specifies that portable applications must not
 .SH PORTABILITY
 These functions were described in the XSI Curses standard, Issue 4.
 As of 2015, the current document is X/Open Curses, Issue 7.
 .SS Differences
 X/Open specifies that portable applications must not

-call \fBinitscr\fR more than once:
+call \fBinitscr\fP more than once:

 .bP
 The portable way to use \fBinitscr\fP is once only,
 .bP
 The portable way to use \fBinitscr\fP is once only,

-using \fBrefresh\fP (see curs_refresh(3X)) to restore the screen after \fBendwin\fP.
+using \fBrefresh\fP (see curs_refresh(3X))
+to restore the screen after \fBendwin\fP.

 .bP
 This implementation allows using \fBinitscr\fP after \fBendwin\fP.
 .PP
 .bP
 This implementation allows using \fBinitscr\fP after \fBendwin\fP.
 .PP

-Old versions of curses, e.g., BSD 4.4, may have returned a null pointer
-from \fBinitscr\fR when an error is detected, rather than exiting.
-It is safe but redundant to check the return value of \fBinitscr\fR
+Old versions of curses, e.g., BSD 4.4, would return a null pointer
+from \fBinitscr\fP when an error is detected, rather than exiting.
+It is safe but redundant to check the return value of \fBinitscr\fP

 in XSI Curses.
 in XSI Curses.

+.PP
+Calling \fBendwin\fP does not dispose of the memory allocated in \fBinitscr\fP
+or \fBnewterm\fP.
+Deleting a \fBSCREEN\fP provides a way to do this:
+.bP
+X/Open Curses does not say what happens to \fBWINDOW\fPs when \fBdelscreen\fP
+\*(``frees storage associated with the \fBSCREEN\fP\*(''
+nor does the SVr4 documentation help,
+adding that it should be called after \fBendwin\fP if a \fBSCREEN\fP
+is no longer needed.
+.bP
+However, \fBWINDOW\fPs are implicitly associated with a \fBSCREEN\fP.
+so that it is reasonable to expect \fBdelscreen\fP to deal with these.
+.bP
+SVr4 curses deletes the standard \fBWINDOW\fP structures
+\fBstdscr\fP and \fBcurscr\fP as well as a work area \fBnewscr\fP.
+SVr4 curses ignores other windows.
+.bP
+Since version 4.0 (1996), ncurses has maintained a list of all windows
+for each screen,
+using that information to delete those windows when \fBdelscreen\fP is called.
+.bP
+NetBSD copied this feature of ncurses in 2001.
+PDCurses follows the SVr4 model,
+deleting only the standard \fBWINDOW\fP structures.

 .SS Unset TERM Variable
 .PP
 If the TERM variable is missing or empty, \fBinitscr\fP uses the
 value \*(``unknown\*('',
 which normally corresponds to a terminal entry with the \fIgeneric\fP
 (\fIgn\fP) capability.
 .SS Unset TERM Variable
 .PP
 If the TERM variable is missing or empty, \fBinitscr\fP uses the
 value \*(``unknown\*('',
 which normally corresponds to a terminal entry with the \fIgeneric\fP
 (\fIgn\fP) capability.

-Generic entries are detected by \fBsetupterm\fP (see curs_terminfo(3X)) and cannot be
-used for full-screen operation.
+Generic entries are detected by \fBsetupterm\fP
+(see curs_terminfo(3X)) and cannot be used for full-screen operation.

 Other implementations may handle a missing/empty TERM variable differently.
 .SS Signal Handlers
 .PP
 Quoting from X/Open Curses, section 3.1.1:
 .RS 5
 Other implementations may handle a missing/empty TERM variable differently.
 .SS Signal Handlers
 .PP
 Quoting from X/Open Curses, section 3.1.1:
 .RS 5

+.hy 0

 .PP
 .PP

-\fICurses implementations may provide for special handling of the SIGINT,
-SIGQUIT and SIGTSTP signals if their disposition is SIG_DFL at the time
-\fBinitscr()\fP is called \fP...
+.I Curses implementations may provide for special handling of the
+.I \fBSIGINT\fP,
+.I \fBSIGQUIT\fP and
+.I \fBSIGTSTP\fP signals
+.I if their disposition is \fBSIG_DFL\fP at the time
+\fBinitscr\fI is called \fR...

 .PP
 .PP

-\fIAny special handling for these signals may remain in effect for the
-life of the process or until the process changes the disposition of
-the signal.\fP
+.I Any special handling for these signals may remain in effect for the
+.I life of the process or until the process changes the disposition of
+.I the signal.

 .PP
 .PP

-\fINone of the Curses functions are required to be safe with respect to signals \fP...
+.I None of the Curses functions are required to be safe
+.I with respect to signals \fP...

 .RE
 .RE

+.hy

 .PP
 This implementation establishes signal handlers during initialization,
 e.g., \fBinitscr\fP or \fBnewterm\fP.
 .PP
 This implementation establishes signal handlers during initialization,
 e.g., \fBinitscr\fP or \fBnewterm\fP.


@@ -228,10 +266,11 @@ This handles the \fIstop\fP signal, used in job control.
 When resuming the process, this implementation discards pending
 input with \fBflushinput\fP (see curs_util(3X)), and repaints the screen
 assuming that it has been completely altered.
 When resuming the process, this implementation discards pending
 input with \fBflushinput\fP (see curs_util(3X)), and repaints the screen
 assuming that it has been completely altered.

-It also updates the saved terminal modes with \fBdef_shell_mode\fP (see curs_kernel(3X)).
+It also updates the saved terminal modes with \fBdef_shell_mode\fP
+(see \fBcurs_kernel\fP(3X)).

 .TP 5
 .B SIGWINCH
 .TP 5
 .B SIGWINCH

-This handles the window-size changes which were initially ignored in
+This handles the window-size changes which were ignored in

 the standardization efforts.
 The handler sets a (signal-safe) variable
 which is later tested in \fBwgetch\fP (see curs_getch(3X)).
 the standardization efforts.
 The handler sets a (signal-safe) variable
 which is later tested in \fBwgetch\fP (see curs_getch(3X)).


@@ -241,10 +280,10 @@ At the same time, \fBwgetch\fP calls \fBresizeterm\fP to adjust the
 standard screen \fBstdscr\fP,
 and update other data such as \fBLINES\fP and \fBCOLS\fP.
 .SH SEE ALSO
 standard screen \fBstdscr\fP,
 and update other data such as \fBLINES\fP and \fBCOLS\fP.
 .SH SEE ALSO

-\fBcurses\fR(3X),
-\fBcurs_kernel\fR(3X),
-\fBcurs_refresh\fR(3X),
-\fBcurs_slk\fR(3X),
-\fBcurs_terminfo\fR(3X),
-\fBcurs_util\fR(3X),
-\fBcurs_variables\fR(3X).
+\fBcurses\fP(3X),
+\fBcurs_kernel\fP(3X),
+\fBcurs_refresh\fP(3X),
+\fBcurs_slk\fP(3X),
+\fBcurs_terminfo\fP(3X),
+\fBcurs_util\fP(3X),
+\fBcurs_variables\fP(3X).