• Last 5 Forum Topics
    Last post

The Web Only This Site



  • MARC

    Mailing list ARChives
    - Search by -


    Computing Dictionary

  • Text Link Ads

  • LINUX man pages
  • Linux Man Page Viewer

    The following form allows you to view linux man pages.



           typeahead - curses input options


           #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);


           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 charac-
           ters 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 explic-
           itly.  Most interactive programs using  curses  set  the  cbreak  mode.
           Note  that cbreak overrides raw.  [See getch(3NCURSES) for a discussion
           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 getch(3NCURSES)
           for a discussion  of  how  these  routines  interact  with  cbreak  and
           The  halfdelay routine is used for half-delay mode, which is similar to
           cbreak mode in that characters typed by the user are immediately avail-
           able to the program.  However, after blocking for tenths tenths of sec-
           onds, 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
           quences  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  in-
           put  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  equiva-
           lent, 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 argument,
           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 termi-
           nal 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  imme-
           diately  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 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,
           X/Open does not define any error conditions.  In  this  implementation,
           functions  with  a window parameter will return an error if it is null.
           Any function will also return an error if the terminal was not initial-
           ized.  Also,
                       returns  an  error  if  its  parameter is outside the range


           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.


           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


           ncurses(3NCURSES), getch(3NCURSES), initscr(3NCURSES), termios(3)

  • Linux

    The Distributions


    The Software


    The News


  • Toll Free
Copyright © 1999 - 2016 by LinuxGuruz