curs_inopts(3X) 														   curs_inopts(3X)

NAME

       cbreak,	nocbreak, echo, noecho, halfdelay, intrflush, keypad, meta, nodelay, notimeout, raw, noraw, noqiflush, qiflush, timeout, wtimeout,
       typeahead - curses input options

SYNOPSIS

       #include <curses.h>

       int cbreak(void);
       int nocbreak(void);
       int echo(void);
       int noecho(void);
       int halfdelay(int tenths);
       int intrflush(WINDOW *win, bool bf);
       int keypad(WINDOW *win, bool bf);
       int meta(WINDOW *win, bool bf);
       int nodelay(WINDOW *win, bool bf);
       int raw(void);
       int noraw(void);
       void noqiflush(void);
       void qiflush(void);
       int notimeout(WINDOW *win, bool bf);
       void timeout(int delay);
       void wtimeout(WINDOW *win, int delay);
       int typeahead(int fd);

DESCRIPTION

       Normally, the tty driver buffers typed characters until a newline or carriage return is typed.  The cbreak routine disables line  buffering
       and erase/kill character-processing (interrupt and flow control characters are unaffected), making characters typed by the user immediately
       available to the program.  The nocbreak routine returns the terminal to normal (cooked) mode.

       Initially the terminal may or may not be in cbreak mode, as the mode is inherited; therefore, a program	should	call  cbreak  or  nocbreak
       explicitly.   Most  interactive programs using curses set the cbreak mode.  Note that cbreak overrides raw.  [See curs_getch(3X) for a dis-
       cussion of how these routines interact with echo and noecho.]

       The echo and noecho routines control whether characters typed by the user are echoed by getch as they are typed.  Echoing by the tty driver
       is always disabled, but initially getch 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  noecho.   [See
       curs_getch(3X) for a discussion of how these routines interact with cbreak and nocbreak.]

       The  halfdelay  routine	is  used for half-delay mode, which is similar to cbreak mode in that characters typed by the user are immediately
       available to the program.  However, after blocking for tenths tenths of seconds, ERR is returned if nothing has been typed.  The  value	of
       tenths must be a number between 1 and 255.  Use nocbreak to leave half-delay mode.

       If  the	intrflush option is enabled, (bf is TRUE), 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 interrupt, but causing curses to have the wrong  idea	of
       what  is  on  the  screen.   Disabling  (bf is FALSE), the option prevents the flush.  The default for the option is inherited from the tty
       driver settings.  The window argument is ignored.

       The keypad option enables the keypad of the user's terminal.  If enabled (bf is TRUE), the user can press a function key (such as an  arrow
       key)  and  wgetch  returns  a single value representing the function key, as in KEY_LEFT.  If disabled (bf is FALSE), curses 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 locally), turning on this option causes the terminal keypad to be turned on when wgetch 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 driver [see termio(7)].	To
       force  8 bits to be returned, invoke meta(win, TRUE); this is equivalent, under POSIX, to setting the CS8 flag on the terminal.	To force 7
       bits to be returned, invoke meta(win, FALSE); this is equivalent, under POSIX, to setting the CS7 flag on the terminal.	The  window  argu-
       ment,  win,  is always ignored.	If the terminfo capabilities smm (meta_on) and rmm (meta_off) are defined for the terminal, smm is sent to
       the terminal when meta(win, TRUE) is called and rmm is sent when meta(win, FALSE) is called.

       The nodelay option causes getch to be a non-blocking call.  If no input is ready, getch returns ERR.  If  disabled  (bf	is  FALSE),  getch
       waits until a key is pressed.

       While  interpreting an input escape sequence, wgetch sets a timer while waiting for the next character.	If notimeout(win, TRUE) is called,
       then wgetch does not set a timer.  The purpose of the timeout is to differentiate between sequences received from a function key and  those
       typed by a user.

       The  raw  and  noraw routines place the terminal into or out of raw mode.  Raw mode is similar to cbreak mode, in that characters typed are
       immediately passed through to the user program.	The differences are that in raw mode, the interrupt, quit, suspend, and flow control char-
       acters  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 curses.

       When the noqiflush routine is used, normal flush of input and output queues associated with the INTR, QUIT and SUSP characters will not	be
       done  [see  termio(7)].	 When  qiflush is called, the queues will be flushed when these control characters are read.  You may want to call
       noqiflush() in a signal handler if you want output to continue as though the interrupt had not occurred, after the handler exits.

       The timeout and wtimeout routines set blocking or non-blocking read for a given window.	If delay is negative, blocking read is used (i.e.,
       waits indefinitely for input).  If delay is zero, then non-blocking read is used (i.e., read returns ERR if no input is waiting).  If delay
       is positive, then read blocks for delay milliseconds, and returns ERR if there is still no input.  Hence, these routines provide  the  same
       functionality as nodelay, plus the additional capability of being able to block for only delay milliseconds (where delay is positive).

       The curses library does ``line-breakout optimization'' by looking for typeahead periodically while updating the screen.	If input is found,
       and it is coming from a tty, the current update is postponed until refresh or doupdate is called again.	This  allows  faster  response	to
       commands typed in advance.  Normally, the input FILE pointer passed to newterm, or stdin in the case that initscr was used, will be used to
       do this typeahead checking.  The typeahead routine specifies that the file descriptor fd is to be used to check for typeahead instead.	If
       fd is -1, then no typeahead checking is done.

RETURN VALUE

       All  routines that return an integer return ERR upon failure and OK (SVr4 specifies only "an integer value other than ERR") upon successful
       completion, unless otherwise noted in the preceding routine descriptions.

PORTABILITY

       These functions are described in the XSI Curses standard, Issue 4.

       The ncurses library obeys the XPG4 standard and the historical practice of the AT&T curses implementations, in that the echo bit is cleared
       when curses initializes the terminal state.  BSD curses differed from this slightly; it left the echo bit on at initialization, but the BSD
       raw call turned it off as a side-effect.  For best portability, set echo or noecho explicitly just after initialization, even if your  pro-
       gram remains in cooked mode.

NOTES

       Note that echo, noecho, halfdelay, intrflush, meta, nodelay, notimeout, noqiflush, qiflush, timeout, and wtimeout may be macros.

       The noraw and nocbreak calls follow historical practice in that they attempt to restore to normal (`cooked') mode from raw and cbreak modes
       respectively.  Mixing raw/noraw and cbreak/nocbreak calls leads to tty driver control states that are hard to predict or understand; it	is
       not recommended.

SEE ALSO

       curses(3X), curs_getch(3X), curs_initscr(3X), termio(7)

																   curs_inopts(3X)