'\" t
.\"***************************************************************************
-.\" Copyright 2018-2021,2023 Thomas E. Dickey *
+.\" Copyright 2018-2023,2024 Thomas E. Dickey *
.\" Copyright 1998-2015,2017 Free Software Foundation, Inc. *
.\" *
.\" Permission is hereby granted, free of charge, to any person obtaining a *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: ncurses.3x,v 1.192 2023/12/31 00:46:04 tom Exp $
-.TH ncurses 3X 2023-12-30 "ncurses 6.4" "Library calls"
+.\" $Id: ncurses.3x,v 1.195 2024/01/05 21:46:58 tom Exp $
+.TH ncurses 3X 2024-01-05 "ncurses 6.4" "Library calls"
.ie \n(.g \{\
.ds `` \(lq
.ds '' \(rq
The following environment symbols are useful for customizing the
runtime behavior of the \fI\%ncurses\fP library.
The most important ones have been already discussed in detail.
-.SS \fICC\fP command-character
+.SS "\fICC\fP command-character"
When set,
change the
.B \%command_character
the C compiler's name,
\fI\%ncurses\fP ignores it if it does not happen to be a single
character.
-.SS \fIBAUDRATE\fP
+.SS "\fIBAUDRATE\fP"
The debugging library checks this environment variable when the application
has redirected output to a file.
The variable's numeric value is used for the baudrate.
If no value is found, \fI\%ncurses\fP uses 9600.
This allows testers to construct repeatable test-cases
that take into account costs that depend on baudrate.
-.SS \fICOLUMNS\fP
+.SS "\fICOLUMNS\fP"
Specify the width of the screen in characters.
Applications running in a windowing environment usually are able to
obtain the width of the window in which they are executing.
Use the \fBuse_tioctl\fP function to update \fI\%COLUMNS\fP or
\fILINES\fP to match the screen size obtained from system calls or the
terminal database.
-.SS \fIESCDELAY\fP
+.SS "\fIESCDELAY\fP"
Specifies the total time,
in milliseconds,
for which \fI\%ncurses\fP will await a character sequence,
in either form,
but setting the environment variable rather than the global variable
does not create problems when compiling an application.
-.SS \fIHOME\fP
+.SS "\fIHOME\fP"
Tells \fI\%ncurses\fP where your home directory is.
That is where it may read and write auxiliary terminal descriptions:
.PP
$HOME/.terminfo
.EE
.RE
-.SS \fILINES\fP
+.SS "\fILINES\fP"
Like \fI\%COLUMNS\fP, specify the height of the screen in characters.
See \fI\%COLUMNS\fP for a detailed description.
-.SS \fIMOUSE_BUTTONS_123\fP
+.SS "\fIMOUSE_BUTTONS_123\fP"
This applies only to the OS/2 EMX port.
It specifies the order of buttons on the mouse.
OS/2 numbers a 3-button mouse inconsistently from other
This variable lets you customize the mouse.
The variable must be three numeric digits 1\-3 in any order, e.g., 123 or 321.
If it is not specified, \fI\%ncurses\fP uses 132.
-.SS \fINCURSES_ASSUMED_COLORS\fP
+.SS "\fINCURSES_ASSUMED_COLORS\fP"
Override the compiled-in assumption that the
terminal's default colors are white-on-black
(see \fBdefault_colors\fP(3X)).
about the colors, set this to "\-1,\-1".
To make it green-on-black, set it to "2,0".
Any positive value from zero to the terminfo \fBmax_colors\fP value is allowed.
-.SS \fINCURSES_CONSOLE2\fP
+.SS "\fINCURSES_CONSOLE2\fP"
This applies only to the MinGW port of \fI\%ncurses\fP.
.PP
The \fBConsole2\fP program's handling of the Microsoft Console API call
mapping coordinates,
explicitly saving and restoring the original screen contents.
Setting the environment variable \fBNCGDB\fP has the same effect.
-.SS \fINCURSES_GPM_TERMS\fP
+.SS "\fINCURSES_GPM_TERMS\fP"
This applies only to \fI\%ncurses\fP configured to use the GPM
interface.
.PP
If the environment variable is absent,
\fI\%ncurses\fP will attempt to open GPM if \fITERM\fP contains
\*(``linux\*(''.
-.SS \fINCURSES_NO_HARD_TABS\fP
+.SS "\fINCURSES_NO_HARD_TABS\fP"
\fI\%ncurses\fP may use tabs as part of cursor movement optimization.
In some cases,
your terminal driver may not handle these properly.
Set this environment variable to any value to disable the feature.
You can also adjust your \fBstty\fP(1) settings to avoid the problem.
-.SS \fINCURSES_NO_MAGIC_COOKIE\fP
+.SS "\fINCURSES_NO_MAGIC_COOKIE\fP"
Some terminals use a magic-cookie feature which requires special handling
to make highlighting and other video attributes display properly.
You can suppress the highlighting entirely for these terminals by
setting this environment variable to any value.
-.SS \fINCURSES_NO_PADDING\fP
+.SS "\fINCURSES_NO_PADDING\fP"
Most of the terminal descriptions in the terminfo database are written
for real \*(``hardware\*('' terminals.
Many people use terminal emulators
to disable all but mandatory padding.
Mandatory padding is used as a part of special control
sequences such as \fBflash\fP.
-.SS \fINCURSES_NO_SETBUF\fP
+.SS "\fINCURSES_NO_SETBUF\fP"
This setting is obsolete.
Before changes
.RS 3
As a special case, the low-level calls such as \fBputp\fP still use the
standard output.
But high-level curses calls do not.
-.SS \fINCURSES_NO_UTF8_ACS\fP
+.SS "\fINCURSES_NO_UTF8_ACS\fP"
During initialization, the \fI\%ncurses\fP library
checks for special cases where VT100 line-drawing (and the corresponding
alternate character set capabilities) described in the terminfo are known
The name \*(``U8\*('' is chosen to be two characters,
to permit it to be used by applications that use \fI\%ncurses\fP'
termcap interface.
-.SS \fINCURSES_TRACE\fP
+.SS "\fINCURSES_TRACE\fP"
During initialization, the \fI\%ncurses\fP debugging library
checks the \fI\%NCURSES_TRACE\fP environment variable.
If it is defined,
file \fBtrace\fP to the current directory.
.PP
See \fBcurs_trace\fP(3X) for more information.
-.SS \fITERM\fP
+.SS "\fITERM\fP"
Denotes your terminal type.
Each terminal type is distinct, though many are similar.
.PP
terminal emulators which allow you to
specify \fITERM\fP as a parameter or configuration value do
not change their behavior to match that setting.
-.SS \fITERMCAP\fP
+.SS "\fITERMCAP\fP"
If the \fI\%ncurses\fP library has been configured with \fItermcap\fP
support, \fI\%ncurses\fP will check for a terminal's description in
termcap form if it is not available in the terminfo database.
the \fITERM\fP environment variable exists.
In either case, setting it directs \fI\%ncurses\fP to ignore
the usual place for this information, e.g., /etc/termcap.
-.SS \fITERMINFO\fP
+.SS "\fITERMINFO\fP"
\fI\%ncurses\fP can be configured to read from multiple terminal
databases.
The \fI\%TERMINFO\fP variable overrides the location for
@TERMINFO@ (corresponding to the \fITERMINFO\fP variable)
.RE
.RE
-.SS \fITERMINFO_DIRS\fP
+.SS "\fITERMINFO_DIRS\fP"
Specifies a list of locations to search for terminal descriptions.
Each location in the list is a terminal database as described in
the section on the \fI\%TERMINFO\fP variable.
.PP
There is no corresponding feature in System V terminfo;
it is an extension developed for \fI\%ncurses\fP.
-.SS \fITERMPATH\fP
+.SS "\fITERMPATH\fP"
If \fI\%TERMCAP\fP does not hold a file name then \fI\%ncurses\fP checks
the \fI\%TERMPATH\fP environment variable.
This is a list of filenames separated by spaces or colons (i.e., ":") on Unix,