Unix/Linux Go Back    

CentOS 7.0 - man page for clearok (centos section 3X)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)

curs_outopts(3X)								 curs_outopts(3X)

       clearok, idlok, idcok, immedok, leaveok, setscrreg, wsetscrreg, scrollok, nl, nonl -
       curses output options

       #include <curses.h>

       int clearok(WINDOW *win, bool bf);
       int idlok(WINDOW *win, bool bf);
       void idcok(WINDOW *win, bool bf);
       void immedok(WINDOW *win, bool bf);
       int leaveok(WINDOW *win, bool bf);
       int setscrreg(int top, int bot);
       int wsetscrreg(WINDOW *win, int top, int bot);
       int scrollok(WINDOW *win, bool bf);
       int nl(void);
       int nonl(void);

       These routines set options that change the style of output within curses.  All options are
       initially  FALSE,  unless otherwise stated.  It is not necessary to turn these options off
       before calling endwin.

       If clearok is called with TRUE as argument, the next call to  wrefresh  with  this  window
       will  clear the screen completely and redraw the entire screen from scratch.  This is use-
       ful when the contents of the screen are uncertain, or in some cases for	a  more  pleasing
       visual  effect.	 If  the  win argument to clearok is the global variable curscr, the next
       call to wrefresh with any window causes the  screen  to	be  cleared  and  repainted  from

       If  idlok  is called with TRUE as second argument, curses considers using the hardware in-
       sert/delete line feature of terminals so equipped.  Calling idlok with FALSE as second ar-
       gument disables use of line insertion and deletion.  This option should be enabled only if
       the application needs insert/delete line, for example, for a screen editor.   It  is  dis-
       abled by default because insert/delete line tends to be visually annoying when used in ap-
       plications where it is not really needed.  If insert/delete line cannot	be  used,  curses
       redraws the changed portions of all lines.

       If  idcok  is  called  with FALSE as second argument, curses no longer considers using the
       hardware insert/delete character feature of terminals so equipped.  Use of  character  in-
       sert/delete  is enabled by default.  Calling idcok with TRUE as second argument re-enables
       use of character insertion and deletion.

       If immedok is called with TRUE as argument, any change in the window image,  such  as  the
       ones  caused  by  waddch,  wclrtobot, wscrl, etc., automatically cause a call to wrefresh.
       However, it may degrade performance considerably, due to repeated calls to  wrefresh.   It
       is disabled by default.

       Normally,  the  hardware  cursor  is  left  at the location of the window cursor being re-
       freshed.  The leaveok option allows the cursor to be left wherever the update  happens  to
       leave  it.   It	is useful for applications where the cursor is not used, since it reduces
       the need for cursor motions.

       The setscrreg and wsetscrreg routines allow the application programmer to set  a  software
       scrolling  region in a window.  The top and bot parameters are the line numbers of the top
       and bottom margin of the scrolling region.  (Line 0 is the top line of  the  window.)   If
       this option and scrollok are enabled, an attempt to move off the bottom margin line causes
       all lines in the scrolling region to scroll one line in the direction of the  first  line.
       Only  the  text of the window is scrolled.  (Note that this has nothing to do with the use
       of a physical scrolling region capability in the terminal, like that  in  the  VT100.   If
       idlok  is enabled and the terminal has either a scrolling region or insert/delete line ca-
       pability, they will probably be used by the output routines.)

       The scrollok option controls what happens when the cursor of a window  is  moved  off  the
       edge of the window or scrolling region, either as a result of a newline action on the bot-
       tom line, or typing the last character of the last line.  If disabled, (bf is FALSE),  the
       cursor  is  left  on the bottom line.  If enabled, (bf is TRUE), the window is scrolled up
       one line (Note that to get the physical scrolling effect on the terminal, it is also  nec-
       essary to call idlok).

       The  nl and nonl routines control whether the underlying display device translates the re-
       turn key into newline on input, and whether it translates newline into  return  and  line-
       feed  on  output  (in  either case, the call addch('\n') does the equivalent of return and
       line feed on the virtual screen).  Initially, these translations do occur.  If you disable
       them  using  nonl, curses will be able to make better use of the line-feed capability, re-
       sulting in faster cursor motion.  Also, curses will then be able to detect the return key.

       The functions setscrreg and wsetscrreg return OK upon success and ERR upon  failure.   All
       other routines that return an integer always return OK.

       X/Open does not define any error conditions.

       In this implementation, those functions that have a window pointer will return an error if
       the window pointer is null.

		   returns an error if the cursor position is about to wrap.

		   returns an error if the scrolling region limits extend outside the window.

       X/Open does not define any error conditions.  This implementation returns an error if  the
       window pointer is null.

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

       The  XSI  Curses standard is ambiguous on the question of whether raw() should disable the
       CRLF translations controlled by nl() and nonl().  BSD curses did turn off  these  transla-
       tions;  AT&T curses (at least as late as SVr1) did not.	We choose to do so, on the theory
       that a programmer requesting raw input wants a clean (ideally 8-bit clean) connection that
       the operating system will not alter.

       Some  historic  curses  implementations had, as an undocumented feature, the ability to do
       the equivalent of clearok(..., 1) by saying touchwin(stdscr) or clear(stdscr).  This  will
       not work under ncurses.

       Earlier	System	V curses implementations specified that with scrollok enabled, any window
       modification triggering a scroll also forced a physical refresh.  XSI Curses does not  re-
       quire  this, and ncurses avoids doing it to perform better vertical-motion optimization at
       wrefresh time.

       The XSI Curses standard does not mention that the cursor should be  made  invisible  as	a
       side-effect  of leaveok.  SVr4 curses documentation does this, but the code does not.  Use
       curs_set to make the cursor invisible.

       Note that clearok, leaveok, scrollok, idcok, nl, nonl and setscrreg may be macros.

       The immedok routine is useful for windows that are used as terminal emulators.

       curses(3X), curs_addch(3X), curs_clear(3X),  curs_initscr(3X),  curs_scroll(3X),  curs_re-
       fresh(3X), curs_variables(3X).

Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums

All times are GMT -4. The time now is 03:47 AM.