Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
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 useful 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 scratch.

       If idlok is called with TRUE as second argument, curses considers using
       the hardware insert/delete line feature of terminals so equipped.
       Calling idlok with FALSE as second argument 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 disabled by default because insert/delete line tends to be
       visually annoying when used in applications 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 insert/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 refreshed.  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.  top and bot 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 capability, 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 bottom 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 necessary to call idlok).

       The nl and nonl routines control whether the underlying display device
       translates the return 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, resulting 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

       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 translations; 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 require this, and ncurses avoids
       doing it to perform better vertical-motion optimization at wrefresh

       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

       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

       curses(3X), curs_addch(3X), curs_clear(3X), curs_initscr(3X),
       curs_scroll(3X), curs_refresh(3X)



Want to link to this manual page? Use this URL:

home | help