.\"***************************************************************************
-.\" 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 *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: curs_initscr.3x,v 1.41 2023/06/10 16:50:22 tom Exp $
-.TH curs_initscr 3X 2023-06-10 "ncurses 6.4" "Library calls"
+.\" $Id: curs_initscr.3x,v 1.62 2024/02/24 20:03:50 tom Exp $
+.TH curs_initscr 3X 2024-02-24 "ncurses 6.4" "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
..
-.ie \n(.g .ds `` \(lq
-.el .ds `` ``
-.ie \n(.g .ds '' \(rq
-.el .ds '' ''
-.na
-.hy 0
.SH NAME
-\fBinitscr\fP,
-\fBnewterm\fP,
-\fBendwin\fP,
-\fBisendwin\fP,
-\fBset_term\fP,
-\fBdelscreen\fP \- \fBcurses\fP screen initialization and manipulation routines
-.ad
-.hy
+\fB\%initscr\fP,
+\fB\%newterm\fP,
+\fB\%endwin\fP,
+\fB\%isendwin\fP,
+\fB\%set_term\fP,
+\fB\%delscreen\fP \-
+initialize, manipulate, or tear down \fIcurses\fR terminal interface
.SH SYNOPSIS
-\fB#include <curses.h>\fP
-.sp
-\fBWINDOW *initscr(void);\fP
-.br
-\fBint endwin(void);\fP
-.sp
-\fBbool isendwin(void);\fP
-.sp
-\fBSCREEN *newterm(const char *\fItype\fB, FILE *\fIoutf\fB, FILE *\fIinf\fB);\fR
-.br
-\fBSCREEN *set_term(SCREEN *\fInew\fB);\fR
-.br
-\fBvoid delscreen(SCREEN* \fIsp\fB);\fR
-.br
+.nf
+\fB#include <curses.h>
+.PP
+\fBWINDOW *initscr(void);
+\fBint endwin(void);
+.PP
+\fBbool isendwin(void);
+.PP
+\fBSCREEN *newterm(const char *\fItype\fP, FILE *\fIoutf\fP, FILE *\fIinf\fP);
+\fBSCREEN *set_term(SCREEN *\fInew\fP);
+\fBvoid delscreen(SCREEN* \fIsp\fP);
+.fi
.SH DESCRIPTION
.SS initscr
\fBinitscr\fP is normally the first \fBcurses\fP routine to call when
message to standard error and exits;
otherwise, a pointer is returned to \fBstdscr\fP.
.SS newterm
-.PP
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,
\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
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
-.PP
The program must also call
\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
Calling \fBrefresh\fP(3X) or \fBdoupdate\fP(3X) after a
temporary escape causes the program to resume visual mode.
.SS isendwin
-.PP
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
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
-.PP
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
-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.
X/Open defines no error conditions.
In this implementation
.bP
-\fBendwin\fP returns an error if the terminal was not initialized.
+\fBendwin\fP returns an error 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) returns an error.
+.RE
.bP
\fBnewterm\fP
returns an error if it cannot allocate the data structures for the screen,
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.
.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
-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,
-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
-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
-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
-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
-NetBSD copied this feature of ncurses in 2001.
+NetBSD copied this feature of \fI\%ncurses\fP in 2001.
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.
-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),
.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
-NetBSD and \fBncurses\fP use the descriptor in \fBTERMINAL\fP for terminal I/O modes,
+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).
-SVr4 curses uses the descriptor in \fBSCREEN\fP.
-.SS Unset TERM Variable
-.PP
-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.
-Other implementations may handle a missing/empty TERM variable differently.
-.SS Signal Handlers
-.PP
-Quoting from X/Open Curses, section 3.1.1:
+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
-.hy 0
.PP
-.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...
+Curses implementations may provide for special handling of the
+\%SIGINT,
+\%SIGQUIT,
+and \%SIGTSTP signals if their disposition is \%SIG_DFL at the time
+.I \%initscr
+is called.\|.\|.
.PP
-.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.
+Any 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.
.PP
-.I None of the Curses functions are required to be safe
-.I with respect to signals \fP...
+None of the Curses functions are required to be safe
+with respect to signals.\|.\|.
.RE
-.hy
.PP
This implementation establishes signal handlers during initialization,
e.g., \fBinitscr\fP or \fBnewterm\fP.
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
-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
-\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
.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.
-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
-which is later tested in \fBwgetch\fP (see curs_getch(3X)).
+which is later tested in \fB\%wgetch\fP(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
standard screen \fBstdscr\fP,
and update other data such as \fBLINES\fP and \fBCOLS\fP.
.SH SEE ALSO
-\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).
+\fB\%curses\fP(3X),
+\fB\%curs_kernel\fP(3X),
+\fB\%curs_refresh\fP(3X),
+\fB\%curs_slk\fP(3X),
+\fB\%curs_terminfo\fP(3X),
+\fB\%curs_util\fP(3X),
+\fB\%curs_variables\fP(3X)