-</PRE>
-<H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
- Normally, the tty driver buffers typed characters until a
- newline or carriage return is typed. The <STRONG>cbreak</STRONG> routine
- disables line buffering and erase/kill character-process-
- ing (interrupt and flow control characters are unaffect-
- ed), making characters typed by the user immediately
- available to the program. The <STRONG>nocbreak</STRONG> routine returns
- the terminal to normal (cooked) mode.
-
- Initially the terminal may or may not be in <STRONG>cbreak</STRONG> mode,
- as the mode is inherited; therefore, a program should call
- <STRONG>cbreak</STRONG> or <STRONG>nocbreak</STRONG> explicitly. Most interactive programs
- using <STRONG>curses</STRONG> set the <STRONG>cbreak</STRONG> mode. Note that <STRONG>cbreak</STRONG> over-
- rides <STRONG>raw</STRONG>. [See <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> for a discussion of how
- these routines interact with <STRONG>echo</STRONG> and <STRONG>noecho</STRONG>.]
-
- The <STRONG>echo</STRONG> and <STRONG>noecho</STRONG> routines control whether characters
- typed by the user are echoed by <STRONG>getch</STRONG> as they are typed.
- Echoing by the tty driver is always disabled, but initial-
- ly <STRONG>getch</STRONG> is in echo mode, so characters typed are echoed.
- Authors of most interactive programs prefer to do their
- own echoing in a controlled area of the screen, or not to
- echo at all, so they disable echoing by calling <STRONG>noecho</STRONG>.
- [See <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> for a discussion of how these routines
- interact with <STRONG>cbreak</STRONG> and <STRONG>nocbreak</STRONG>.]
-
- The <STRONG>halfdelay</STRONG> routine is used for half-delay mode, which
- is similar to <STRONG>cbreak</STRONG> mode in that characters typed by the
- user are immediately available to the program. However,
- after blocking for <EM>tenths</EM> tenths of seconds, ERR is re-
- turned if nothing has been typed. The value of <STRONG>tenths</STRONG>
- must be a number between 1 and 255. Use <STRONG>nocbreak</STRONG> to leave
- half-delay mode.
-
- If the <STRONG>intrflush</STRONG> option is enabled, (<EM>bf</EM> is <STRONG>TRUE</STRONG>), when an
- interrupt key is pressed on the keyboard (interrupt,
- break, quit) all output in the tty driver queue will be
- flushed, giving the effect of faster response to the in-
- terrupt, but causing <STRONG>curses</STRONG> to have the wrong idea of what
- is on the screen. Disabling (<EM>bf</EM> is <STRONG>FALSE</STRONG>), the option
- prevents the flush. The default for the option is inher-
- ited from the tty driver settings. The window argument is
- ignored.
-
- The <STRONG>keypad</STRONG> option enables the keypad of the user's termi-
- nal. If enabled (<EM>bf</EM> is <STRONG>TRUE</STRONG>), the user can press a func-
- tion key (such as an arrow key) and <STRONG>wgetch</STRONG> returns a sin-
- gle value representing the function key, as in <STRONG>KEY_LEFT</STRONG>.
- If disabled (<EM>bf</EM> is <STRONG>FALSE</STRONG>), <STRONG>curses</STRONG> does not treat function
- keys specially and the program has to interpret the escape
- sequences itself. If the keypad in the terminal can be
- turned on (made to transmit) and off (made to work local-
- ly), turning on this option causes the terminal keypad to
- be turned on when <STRONG>wgetch</STRONG> is called. The default value for
- keypad is false.
-
- Initially, whether the terminal returns 7 or 8 significant
- bits on input depends on the control mode of the tty driv-
- er [see <STRONG>termio(7)</STRONG>]. To force 8 bits to be returned, in-
- voke <STRONG>meta</STRONG>(<EM>win</EM>, <STRONG>TRUE</STRONG>); this is equivalent, under POSIX, to
- setting the CS8 flag on the terminal. To force 7 bits to
- be returned, invoke <STRONG>meta</STRONG>(<EM>win</EM>, <STRONG>FALSE</STRONG>); this is equivalent,
- under POSIX, to setting the CS7 flag on the terminal. The
- window argument, <EM>win</EM>, is always ignored. If the terminfo
- capabilities <STRONG>smm</STRONG> (meta_on) and <STRONG>rmm</STRONG> (meta_off) are defined
- for the terminal, <STRONG>smm</STRONG> is sent to the terminal when
- <STRONG>meta</STRONG>(<EM>win</EM>, <STRONG>TRUE</STRONG>) is called and <STRONG>rmm</STRONG> is sent when <STRONG>meta</STRONG>(<EM>win</EM>,
- <STRONG>FALSE</STRONG>) is called.
-
- The <STRONG>nodelay</STRONG> option causes <STRONG>getch</STRONG> to be a non-blocking call.
- If no input is ready, <STRONG>getch</STRONG> returns <STRONG>ERR</STRONG>. If disabled (<EM>bf</EM>
- is <STRONG>FALSE</STRONG>), <STRONG>getch</STRONG> waits until a key is pressed.
-
- While interpreting an input escape sequence, <STRONG>wgetch</STRONG> sets a
- timer while waiting for the next character. If <STRONG>notime-</STRONG>
- <STRONG>out(</STRONG><EM>win</EM>, <STRONG>TRUE</STRONG>) is called, then <STRONG>wgetch</STRONG> does not set a
- timer. The purpose of the timeout is to differentiate be-
- tween sequences received from a function key and those
- typed by a user.
-
- The <STRONG>raw</STRONG> and <STRONG>noraw</STRONG> routines place the terminal into or out
- of raw mode. Raw mode is similar to <STRONG>cbreak</STRONG> mode, in that
- characters typed are immediately passed through to the us-
- er program. The differences are that in raw mode, the in-
- terrupt, quit, suspend, and flow control characters are
- all passed through uninterpreted, instead of generating a
- signal. The behavior of the BREAK key depends on other
- bits in the tty driver that are not set by <STRONG>curses</STRONG>.
-
- When the <STRONG>noqiflush</STRONG> routine is used, normal flush of input
- and output queues associated with the <STRONG>INTR</STRONG>, <STRONG>QUIT</STRONG> and <STRONG>SUSP</STRONG>
- characters will not be done [see <STRONG>termio(7)</STRONG>]. When <STRONG>qiflush</STRONG>
- is called, the queues will be flushed when these control
- characters are read. You may want to call <STRONG>noqiflush()</STRONG> in
- a signal handler if you want output to continue as though
- the interrupt had not occurred, after the handler exits.