ncurses 6.5 - patch 20240615

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

diff --git a/man/curs_initscr.3x b/man/curs_initscr.3x
index 3bf80125cd7280b2a2c5bddf05fd414db97ebc0c..1e30604a7afff180fa535a2a1c2664bee1bcbe44 100644 (file)
--- a/man/curs_initscr.3x
+++ b/man/curs_initscr.3x
@@ -1,5 +1,5 @@
 .\"***************************************************************************
 .\"***************************************************************************

-.\" Copyright 2018-2022,2023 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  *


@@ -27,8 +27,8 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"

-.\" $Id: curs_initscr.3x,v 1.53 2023/10/07 21:19:07 tom Exp $
-.TH curs_initscr 3X 2023-10-07 "ncurses 6.4" "Library calls"
+.\" $Id: curs_initscr.3x,v 1.75 2024/06/08 20:34:23 tom Exp $
+.TH curs_initscr 3X 2024-06-08 "ncurses @NCURSES_MAJOR@.@NCURSES_MINOR@" "Library calls"

 .ie \n(.g \{\
 .ds `` \(lq
 .ds '' \(rq
 .ie \n(.g \{\
 .ds `` \(lq
 .ds '' \(rq


@@ -91,7 +91,7 @@ terminal cannot support a screen-oriented program, would also use
 \fBnewterm\fP.
 .PP
 The routine \fBnewterm\fP should be called once for each terminal.
 \fBnewterm\fP.
 .PP
 The routine \fBnewterm\fP should be called once for each terminal.

-It returns a variable of type \fBSCREEN *\fP which should be saved
+It returns a variable of type \fISCREEN *\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


@@ -104,8 +104,8 @@ an input stream connected to the terminal
 If the \fItype\fP parameter is \fBNULL\fP, \fB$TERM\fP will be used.
 .PP
 The file descriptor of the output stream is passed to \fBsetupterm\fP(3X),
 If the \fItype\fP parameter is \fBNULL\fP, \fB$TERM\fP will be used.
 .PP
 The file descriptor of the output stream is passed to \fBsetupterm\fP(3X),

-which returns a pointer to a \fBTERMINAL\fP structure.
-\fBnewterm\fP's return value holds a pointer to the \fBTERMINAL\fP structure.
+which returns a pointer to a \fI\%TERMINAL\fP structure.
+\fBnewterm\fP's return value holds a pointer to the \fI\%TERMINAL\fP structure.

 .SS endwin
 The program must also call
 \fBendwin\fP for each terminal being used before exiting from \fBcurses\fP.
 .SS endwin
 The program must also call
 \fBendwin\fP for each terminal being used before exiting from \fBcurses\fP.


@@ -138,14 +138,14 @@ and \fBFALSE\fP otherwise.
 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 \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.

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

 all other routines affect only the current terminal.
 .SS delscreen
 The \fBdelscreen\fP routine frees storage associated with the
 all other routines affect only the current terminal.
 .SS delscreen
 The \fBdelscreen\fP routine frees storage associated with the

-\fBSCREEN\fP data structure.
+\fISCREEN\fP data structure.

 The \fBendwin\fP routine does not do
 this, so \fBdelscreen\fP should be called after \fBendwin\fP if a
 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.
+particular \fISCREEN\fP is no longer needed.

 .SH RETURN VALUE
 \fBendwin\fP returns the integer \fBERR\fP upon failure and \fBOK\fP
 upon successful completion.
 .SH RETURN VALUE
 \fBendwin\fP returns the integer \fBERR\fP upon failure and \fBOK\fP
 upon successful completion.


@@ -155,10 +155,23 @@ Routines that return pointers always return \fBNULL\fP on error.
 X/Open defines no error conditions.
 In this implementation
 .bP
 X/Open defines no error conditions.
 In this implementation
 .bP

-\fBendwin\fP returns an error if the terminal was not initialized.
+\fBendwin\fP returns
+.B ERR
+if
+.RS
+.bP
+the terminal was not initialized, or
+.bP
+\fBendwin\fP is called more than once without updating the screen, or
+.bP
+\fBreset_shell_mode\fP(3X) return
+.BR ERR "."
+.RE

 .bP
 \fBnewterm\fP
 .bP
 \fBnewterm\fP

-returns an error if it cannot allocate the data structures for the screen,
+returns
+.B ERR
+if it cannot allocate the data structures for the screen,

 or for the top-level windows within the screen,
 i.e.,
 \fBcurscr\fP, \fBnewscr\fP, or \fBstdscr\fP.
 or for the top-level windows within the screen,
 i.e.,
 \fBcurscr\fP, \fBnewscr\fP, or \fBstdscr\fP.


@@ -166,14 +179,14 @@ i.e.,
 \fBset_term\fP
 returns no error.
 .SH PORTABILITY
 \fBset_term\fP
 returns no error.
 .SH PORTABILITY

-These functions were described in the XSI Curses standard, Issue 4.
+These functions were described in X/Open Curses, Issue 4.

 As of 2015, the current document is X/Open Curses, Issue 7.
 .SS Differences
 As of 2015, the current document is X/Open Curses, Issue 7.
 .SS Differences

-X/Open specifies that portable applications must not
+X/Open Curses specifies that portable applications must not

 call \fBinitscr\fP more than once:
 .bP
 The portable way to use \fBinitscr\fP is once only,
 call \fBinitscr\fP more than once:
 .bP
 The portable way to use \fBinitscr\fP is once only,

-using \fBrefresh\fP (see curs_refresh(3X))
+using \fB\%refresh\fP(3X)

 to restore the screen after \fBendwin\fP.
 .bP
 This implementation allows using \fBinitscr\fP after \fBendwin\fP.
 to restore the screen after \fBendwin\fP.
 .bP
 This implementation allows using \fBinitscr\fP after \fBendwin\fP.


@@ -181,36 +194,36 @@ This implementation allows using \fBinitscr\fP after \fBendwin\fP.
 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
 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 X/Open Curses.

 .PP
 Calling \fBendwin\fP does not dispose of the memory allocated in \fBinitscr\fP
 or \fBnewterm\fP.
 .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:
+Deleting a \fISCREEN\fP provides a way to do this:

 .bP
 .bP

-X/Open Curses does not say what happens to \fBWINDOW\fPs when \fBdelscreen\fP
-\*(``frees storage associated with the \fBSCREEN\fP\*(''
+X/Open Curses does not say what happens to \fI\%WINDOW\fPs when \fBdelscreen\fP
+\*(``frees storage associated with the \fISCREEN\fP\*(''

 nor does the SVr4 documentation help,
 nor does the SVr4 documentation help,

-adding that it should be called after \fBendwin\fP if a \fBSCREEN\fP
+adding that it should be called after \fBendwin\fP if a \fISCREEN\fP

 is no longer needed.
 .bP
 is no longer needed.
 .bP

-However, \fBWINDOW\fPs are implicitly associated with a \fBSCREEN\fP.
+However, \fI\%WINDOW\fPs are implicitly associated with a \fISCREEN\fP.

 so that it is reasonable to expect \fBdelscreen\fP to deal with these.
 .bP
 so that it is reasonable to expect \fBdelscreen\fP to deal with these.
 .bP

-SVr4 curses deletes the standard \fBWINDOW\fP structures
+SVr4 curses deletes the standard \fI\%WINDOW\fP structures

 \fBstdscr\fP and \fBcurscr\fP as well as a work area \fBnewscr\fP.
 SVr4 curses ignores other windows.
 .bP
 \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,
+Since version 4.0 (1996),
+\fI\%ncurses\fP has maintained a list of all windows for each screen,

 using that information to delete those windows when \fBdelscreen\fP is called.
 .bP
 using that information to delete those windows when \fBdelscreen\fP is called.
 .bP

-NetBSD copied this feature of ncurses in 2001.
+NetBSD copied this feature of \fI\%ncurses\fP in 2001.

 PDCurses follows the SVr4 model,
 PDCurses follows the SVr4 model,

-deleting only the standard \fBWINDOW\fP structures.
-.SS High-level versus low-level
+deleting only the standard \fI\%WINDOW\fP structures.
+.SS "High-level versus Low-level"

 Different implementations may disagree regarding the level of some functions.
 Different implementations may disagree regarding the level of some functions.

-For example, \fBSCREEN\fP (returned by \fBnewterm\fP) and
-\fBTERMINAL\fP (returned by \fBsetupterm\fP(3X)) hold file descriptors for
+For example, \fISCREEN\fP (returned by \fBnewterm\fP) and
+\fI\%TERMINAL\fP (returned by \fBsetupterm\fP(3X)) hold file descriptors for

 the output stream.
 If an application switches screens using \fBset_term\fR,
 or switches terminals using \fBset_curterm\fP(3X),
 the output stream.
 If an application switches screens using \fBset_term\fR,
 or switches terminals using \fBset_curterm\fP(3X),


@@ -219,25 +232,26 @@ behavior depending on which structure holds the corresponding descriptor.
 .PP
 For example
 .bP
 .PP
 For example
 .bP

-NetBSD's \fBbaudrate\fP(3X) function uses the descriptor in \fBTERMINAL\fP.
-\fBncurses\fP and SVr4 use the descriptor in \fBSCREEN\fP.
+NetBSD's \fBbaudrate\fP(3X) function uses the descriptor in \fI\%TERMINAL\fP.
+\fI\%ncurses\fP and SVr4 use the descriptor in \fISCREEN\fP.

 .bP
 .bP

-NetBSD and \fBncurses\fP use the descriptor
-in \fBTERMINAL\fP
+NetBSD and \fI\%ncurses\fP use the descriptor
+in \fI\%TERMINAL\fP

 for terminal I/O modes,
 e.g.,
 \fBdef_shell_mode\fP(3X),
 \fBdef_prog_mode\fP(3X).
 for terminal I/O modes,
 e.g.,
 \fBdef_shell_mode\fP(3X),
 \fBdef_prog_mode\fP(3X).

-SVr4 curses uses the descriptor in \fBSCREEN\fP.
-.SS Unset TERM Variable
-If the TERM variable is missing or empty, \fBinitscr\fP uses the
+SVr4 curses uses the descriptor in \fISCREEN\fP.
+.SS "Unset \fITERM\fP Variable"
+If the \fITERM\fP 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(3X)
 and cannot be used for full-screen operation.
 value \*(``unknown\*('',
 which normally corresponds to a terminal entry with the \fIgeneric\fP
 (\fIgn\fP) capability.
 Generic entries are detected by \fBsetupterm\fP(3X)
 and cannot be used for full-screen operation.

-Other implementations may handle a missing/empty TERM variable differently.
-.SS Signal Handlers
+Other implementations may handle
+a missing/empty \fITERM\fP variable differently.
+.SS "Signal Handlers"

 Quoting from X/Open Curses Issue 7, section 3.1.1:
 .RS 5
 .PP
 Quoting from X/Open Curses Issue 7, section 3.1.1:
 .RS 5
 .PP


@@ -262,18 +276,19 @@ Applications which must handle these signals should set up the corresponding
 handlers \fIafter\fP initializing the library:
 .TP 5
 .B SIGINT
 handlers \fIafter\fP initializing the library:
 .TP 5
 .B SIGINT

-The handler \fIattempts\fP to cleanup the screen on exit.
+The handler \fIattempts\fP to clean up the screen on exit.

 Although it \fIusually\fP works as expected, there are limitations:
 .RS 5
 .bP
 Although it \fIusually\fP works as expected, there are limitations:
 .RS 5
 .bP

-Walking the \fBSCREEN\fP list is unsafe, since all list management
+Walking the \fISCREEN\fP list is unsafe, since all list management

 is done without any signal blocking.
 .bP
 On systems which have \fBREENTRANT\fP turned on, \fBset_term\fP uses
 functions which could deadlock or misbehave in other ways.
 .bP
 is done without any signal blocking.
 .bP
 On systems which have \fBREENTRANT\fP turned on, \fBset_term\fP uses
 functions which could deadlock or misbehave in other ways.
 .bP

-\fBendwin\fP calls other functions, many of which use stdio or
-other library functions which are clearly unsafe.
+\fBendwin\fP calls other functions,
+many of which use \fI\%stdio\fP(3) or other library functions which are
+clearly unsafe.

 .RE
 .TP 5
 .B SIGTERM
 .RE
 .TP 5
 .B SIGTERM


@@ -284,19 +299,32 @@ purpose than \fBSIGQUIT\fP (which is used in debugging).
 .B SIGTSTP
 This handles the \fIstop\fP signal, used in job control.
 When resuming the process, this implementation discards pending
 .B SIGTSTP
 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
+input with \fB\%flushinp\fP(3X), and repaints the screen

 assuming that it has been completely altered.
 assuming that it has been completely altered.

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

 .TP 5
 .B SIGWINCH
 This handles the window-size changes which were ignored in
 the standardization efforts.
 The handler sets a (signal-safe) variable
 .TP 5
 .B SIGWINCH
 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)).
-If \fBkeypad\fP has been enabled for the corresponding window,
-\fBwgetch\fP returns the key symbol \fBKEY_RESIZE\fP.
-At the same time, \fBwgetch\fP calls \fBresizeterm\fP to adjust the
+that is later tested by \fB\%wgetch\fP(3X) and \fB\%wget_wch\fP(3X).
+.RS
+.bP
+.B \%wgetch
+returns the key code
+.BR \%KEY_RESIZE "."
+.bP
+.B \%wget_wch
+returns
+.B \%KEY_CODE_YES
+and sets its
+.I wch
+parameter to
+.BR \%KEY_RESIZE "."
+.RE
+.IP
+At the same time, \fI\%ncurses\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