+ work with a remote host over a slow communication channel. If the host
+ running a <EM>curses</EM> application does not receive the characters of an
+ escape sequence in a timely manner, the library can interpret them as
+ multiple key stroke events.
+
+ <STRONG>xterm(1)</STRONG> mouse events are a form of escape sequence; therefore, if your
+ application makes heavy use of multiple-clicking, you may wish to
+ lengthen the default value because the delay applies to the composite
+ multi-click event as well as the individual clicks.
+
+ Portable applications should not rely upon the presence of <STRONG>ESCDELAY</STRONG> in
+ either form, but setting the environment variable rather than the
+ global variable does not create problems when compiling an application.
+
+ If <STRONG><A HREF="curs_inopts.3x.html">keypad(3x)</A></STRONG> is disabled for the <EM>curses</EM> window receiving input, a
+ program must disambiguate escape sequences itself.
+
+
+</PRE><H3><a name="h3-HOME"><EM>HOME</EM></a></H3><PRE>
+ <EM>ncurses</EM> may read and write auxiliary terminal descriptions in <EM>.termcap</EM>
+ and <EM>.terminfo</EM> files in the user's home directory.
+
+
+</PRE><H3><a name="h3-LINES"><EM>LINES</EM></a></H3><PRE>
+ This counterpart to <EM>COLUMNS</EM> specifies the height of the screen in
+ characters. The corresponding <EM>terminfo</EM> capability and code is <STRONG>lines</STRONG>.
+ See the description of the <EM>COLUMNS</EM> variable above.
+
+
+</PRE><H3><a name="h3-MOUSE_BUTTONS_123"><EM>MOUSE_BUTTONS_123</EM></a></H3><PRE>
+ (OS/2 EMX port only) OS/2 numbers a three-button mouse inconsistently
+ with other platforms, such that 1 is the left button, 2 the right, and
+ 3 the middle. This variable customizes the mouse button numbering.
+ Its value must be three digits 1-3 in any order. By default, <EM>ncurses</EM>
+ assumes a numbering of "132".
+
+
+</PRE><H3><a name="h3-NCURSES_ASSUMED_COLORS"><EM>NCURSES_ASSUMED_COLORS</EM></a></H3><PRE>
+ If set, this variable overrides the <EM>ncurses</EM> library's compiled-in
+ assumption that the terminal's default colors are white on black; see
+ <STRONG><A HREF="default_colors.3x.html">default_colors(3x)</A></STRONG>. Set the foreground and background color values
+ with this environment variable by assigning it two integer values
+ separated by a comma, indicating foregound and background color
+ numbers, respectively.
+
+ For example, to tell <EM>ncurses</EM> not to assume anything about the colors,
+ use a value of "-1,-1". To make the default color scheme green on
+ black, use "2,0". <EM>ncurses</EM> accepts integral values from -1 up to the
+ value of the <EM>terminfo</EM> <STRONG>max_colors</STRONG> (<STRONG>colors</STRONG>) capability.
+
+
+</PRE><H3><a name="h3-NCURSES_CONSOLE2"><EM>NCURSES_CONSOLE2</EM></a></H3><PRE>
+ (MinGW port only) The <EM>Console2</EM> program defectively handles the
+ Microsoft Console API call <EM>CreateConsoleScreenBuffer</EM>. Applications
+ that use it will hang. However, it is possible to simulate the action
+ of this call by mapping coordinates, explicitly saving and restoring
+ the original screen contents. Setting the environment variable <EM>NCGDB</EM>
+ has the same effect.
+
+
+</PRE><H3><a name="h3-NCURSES_GPM_TERMS"><EM>NCURSES_GPM_TERMS</EM></a></H3><PRE>
+ (Linux only) When <EM>ncurses</EM> is configured to use the GPM interface, this
+ variable may list one or more terminal names against which the <EM>TERM</EM>
+ variable (see below) is matched. An empty value disables the GPM
+ interface, using <EM>ncurses</EM>'s built-in support for <STRONG>xterm(1)</STRONG> mouse
+ protocols instead. If the variable is absent, <EM>ncurses</EM> attempts to open
+ GPM if <EM>TERM</EM> contains "linux".
+
+
+</PRE><H3><a name="h3-NCURSES_NO_HARD_TABS"><EM>NCURSES_NO_HARD_TABS</EM></a></H3><PRE>
+ <EM>ncurses</EM> may use tab characters in cursor movement optimization. In
+ some cases, your terminal driver may not handle them properly. Set
+ this environment variable to any value to disable the feature. You can
+ also adjust your <STRONG>stty(1)</STRONG> settings to avoid the problem.
+
+
+</PRE><H3><a name="h3-NCURSES_NO_MAGIC_COOKIE"><EM>NCURSES_NO_MAGIC_COOKIE</EM></a></H3><PRE>
+ Many terminals store video attributes as a property of a character
+ cell, as <EM>curses</EM> does. Historically, some recorded changes in video
+ attributes as data that logically <EM>occupies</EM> character cells on the
+ display, switching attributes on or off, similarly to tags in a markup
+ language; these are termed "magic cookies", and must be subsequently
+ overprinted. If the <EM>terminfo</EM> entry for your terminal type does not
+ adequately describe its handling of magic cookies, set this variable to
+ any value to instruct <EM>ncurses</EM> to disable attributes entirely.
+
+
+</PRE><H3><a name="h3-NCURSES_NO_PADDING"><EM>NCURSES_NO_PADDING</EM></a></H3><PRE>
+ Most terminal type descriptions in the <EM>terminfo</EM> database detail
+ hardware devices. Many people use <EM>curses</EM>-based applications in
+ terminal emulator programs that run in a windowing environment. These
+ programs can duplicate all of the important features of a hardware
+ terminal, but often lack their limitations. Chief among these absent
+ drawbacks is the problem of data flow management; that is, limiting the
+ speed of communication to what the hardware could handle. Unless a
+ hardware terminal is interfaced into a terminal concentrator (which
+ does flow control), an application must manage flow control itself to
+ prevent overruns and data loss.
+
+ A solution that comes at no hardware cost is for an application to
+ pause after directing a terminal to execute an operation that it
+ performs slowly, such as clearing the display. Many terminal type
+ descriptions, including that for the VT100, embed delay specifications
+ in capabilities. You may wish to use these temrinal descriptions
+ without paying the performance penalty. Set <EM>NCURSES</EM><STRONG>_</STRONG><EM>NO</EM><STRONG>_</STRONG><EM>PADDING</EM> to any
+ value to disable all but mandatory padding. Mandatory padding is used
+ by such terminal capabilities as <STRONG>flash_screen</STRONG> (<STRONG>flash</STRONG>).
+
+
+</PRE><H3><a name="h3-NCURSES_NO_SETBUF"><EM>NCURSES_NO_SETBUF</EM></a></H3><PRE>
+ (Obsolete) Prior to internal changes developed in <EM>ncurses</EM> 5.9 (patches
+ 20120825 through 20130126), the library used <STRONG>setbuf(3)</STRONG> to enable fully
+ buffered output when initializing the terminal. This was done, as in
+ SVr4 <EM>curses</EM>, to increase performance. For testing purposes, both of
+ <EM>ncurses</EM> and of certain applications, this feature was made optional.
+ Setting this variable disabled output buffering, leaving the output
+ stream in the original (usually line-buffered) mode.
+
+ Nowadays, <EM>ncurses</EM> performs its own buffering and does not require this
+ workaround; it does not modify the buffering of the standard output
+ stream. This approach makes signal handling, as for interrupts, more
+ robust. A drawback is that certain unconventional programs mixed
+ <STRONG>stdio(3)</STRONG> calls with <EM>ncurses</EM> calls and (usually) got the behavior they
+ expected. This is no longer the case; <EM>ncurses</EM> does not write to the
+ standard output file descriptor through a <EM>stdio</EM>-buffered stream.
+
+ As a special case, low-level API calls such as <STRONG><A HREF="curs_terminfo.3x.html">putp(3x)</A></STRONG> still use the
+ standard output stream. High-level <EM>curses</EM> calls such as <STRONG><A HREF="curs_printw.3x.html">printw(3x)</A></STRONG> do
+ not.
+
+
+</PRE><H3><a name="h3-NCURSES_NO_UTF8_ACS"><EM>NCURSES_NO_UTF8_ACS</EM></a></H3><PRE>
+ At initialization, <EM>ncurses</EM> inspects the <EM>TERM</EM> environment variable for
+ special cases where VT100 forms-drawing characters (and the
+ corresponding alternate character set <EM>terminfo</EM> capabilities) are known
+ to be unsupported by terminal types that otherwise claim VT100
+ compatibility. Specifically, when running in a UTF-8 locale, the Linux
+ virtual console device and the GNU <STRONG>screen(1)</STRONG> program ignore them. Set
+ this variable to a nonzero value to instruct <EM>ncurses</EM> that the
+ terminal's ACS support is broken; the library then outputs Unicode code
+ points that correspond to the forms-drawing characters. Set it to zero
+ (or a non-integer) to disable the special check for terminal type names
+ matching "linux" or "screen", directing <EM>ncurses</EM> to assume that the ACS
+ feature works if the terminal type description advertises it.
+
+ As an alternative to use of this variable, <EM>ncurses</EM> checks for an
+ extended <EM>terminfo</EM> numeric capability <STRONG>U8</STRONG> that can be compiled using "<STRONG>tic</STRONG>
+ <STRONG>-x</STRONG>". Examples follow.
projects / ncurses.git / blobdiff