# curs_scroll 3x 2023-12-16 ncurses 6.4 Library calls

    curs_scroll(3x)                  Library calls                 curs_scroll(3x)

## NAME

           scroll, scrl, wscrl - scroll a curses window

## SYNOPSIS

           #include <curses.h>

           int scroll(WINDOW *win);

           int scrl(int n);
           int wscrl(WINDOW *win, int n);

## DESCRIPTION

           scroll  scrolls  the  given window up one line.  That is, every visible
           line we might number i becomes line i-1.  The text of the top  line  in
           the  window  disappears  and  the  bottom  line is populated with blank
           characters; see bkgd(3x) or bkgrnd(3x).  As  an  optimization,  if  the
           scrolling  region  of  the  window  is  the entire screen, the physical
           screen may be scrolled at the same time; see curscr(3x).

           scrl and wscrl scroll  stdscr  or  the  specified  window  up  or  down
           depending on the sign of n.

           o   For positive n, line i+n becomes i (scrolling up);

           o   for negative n, line i-n becomes i (scrolling down).

           The  cursor does not move.  These functions perform no operation unless
           scrolling is enabled for the window via scrollok(3x).

## RETURN VALUE

           These functions return ERR upon failure and OK upon success.

           ncurses returns ERR if scrolling is not  enabled  in  the  window,  for
           example with scrollok(3x), or if the WINDOW pointer is null.

## NOTES

           Unusually,  there  is  no wscroll function; scroll behaves as one would
           expect wscroll to, accepting a WINDOW pointer argument.

           scrl and scroll may be implemented as macros.

## PORTABILITY

           X/Open Curses, Issue 4, describes these functions.  It defines no error
           conditions.

           SVr4  specifies  only "an integer value other than ERR" as a successful
           return value.

           SVr4  indicates  that  the   optimization   of   physically   scrolling
           immediately  if  the scroll region is the entire screen "is" performed,
           not "may be" performed.  ncurses deliberately does not  guarantee  that
           this  will occur, to leave open the possibility of smarter optimization
           of multiple scroll actions on the next update.

           Neither SVr4 curses nor  X/Open  Curses  specify  whether  the  current
           attribute  or  current  color  pair  of  blanks generated by the scroll
           function are zeroed.  ncurses does so.

## SEE ALSO

           curses(3x), curs_outopts(3x)

    ncurses 6.4                       2023-12-16                   curs_scroll(3x)