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(3NCURSES)  or  bkgrnd(3NCURSES).  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(3NCURSES).

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

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

       •   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(3NCURSES).

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(3NCURSES), 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

       ncurses(3NCURSES), outopts(3NCURSES)