curs_inopts.3x.html

ncurses-5.4

       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
       locally),  turning on this option causes the terminal key-
       pad 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
       driver  [see  <STRONG><A HREF="termio.7.html">termio(7)</A></STRONG>].  To force 8 bits to be returned,
       invoke <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  equiva-
       lent,  under  POSIX, to setting the CS7 flag on the termi-
       nal.  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
       between 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
       user program.  The differences are that in raw  mode,  the
       interrupt,  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><A HREF="termio.7.html">termio(7)</A></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.

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

       The  <STRONG>curses</STRONG> 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 <STRONG>refresh</STRONG> or  <STRONG>doupdate</STRONG>
       is  called again.  This allows faster response to commands
       typed in advance.  Normally, the input FILE pointer passed
       to  <STRONG>newterm</STRONG>,  or  <STRONG>stdin</STRONG> in the case that <STRONG>initscr</STRONG> was used,
       will be used to do this typeahead checking.  The <STRONG>typeahead</STRONG>
       routine  specifies  that  the  file descriptor <EM>fd</EM> is to be
       used to check for typeahead instead.  If <EM>fd</EM> is -1, then no
       typeahead checking is done.


</PRE>
<H2>RETURN VALUE</H2><PRE>
       All  routines that return an integer return <STRONG>ERR</STRONG> upon fail-
       ure and OK (SVr4 specifies only "an  integer  value  other
       than  <STRONG>ERR</STRONG>")  upon  successful completion, unless otherwise
       noted in the preceding routine descriptions.


</PRE>
<H2>PORTABILITY</H2><PRE>
       These functions are described in the XSI Curses  standard,
       Issue 4.

       The  ncurses  library obeys the XPG4 standard and the his-
       torical practice of the AT&amp;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 <STRONG>raw</STRONG>
       call turned it off as a side-effect.  For  best  portabil-
       ity,  set echo or noecho explicitly just after initializa-
       tion, even if your program remains in cooked mode.


</PRE>
<H2>NOTES</H2><PRE>
       Note that <STRONG>echo</STRONG>, <STRONG>noecho</STRONG>, <STRONG>halfdelay</STRONG>, <STRONG>intrflush</STRONG>, <STRONG>meta</STRONG>,  <STRONG>node-</STRONG>
       <STRONG>lay</STRONG>,  <STRONG>notimeout</STRONG>, <STRONG>noqiflush</STRONG>, <STRONG>qiflush</STRONG>, <STRONG>timeout</STRONG>, and <STRONG>wtimeout</STRONG>
       may be macros.

       The <STRONG>noraw</STRONG> and <STRONG>nocbreak</STRONG> 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.


</PRE>
<H2>SEE ALSO</H2><PRE>
       <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>, <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG><A HREF="termio.7.html">termio(7)</A></STRONG>



                                                  <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG>
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