Manual Pages  — curs_scroll

 scroll,  scrl,  wscrl - scroll a curses window

SYNOPSIS DESCRIPTION RETURN VALUE NOTES PORTABILITY SEE ALSO

#include <curses.h>

int scroll(WINDOW *win);

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

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.

»	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(3X).

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.

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.

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.

 curses(3X),  curs_outopts(3X)