curs_scroll(3)curs_scroll(3)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
The scroll routine scrolls the window up one line. This involves
moving the lines in the window data structure. As an optimization, if
the scrolling region of the window is the entire screen, the physical
screen may be scrolled at the same time.
For positive n, the scrl and wscrl routines scroll the window up n
lines (line i+n becomes i); otherwise scroll the window down n lines.
This involves moving the lines in the window character image structure.
The current cursor position is not changed.
For these functions to work, scrolling must be enabled via scrollok.
RETURN VALUE
These routines return ERR upon failure, and OK (SVr4 only specifies "an
integer value other than ERR") upon successful completion.
X/Open defines no error conditions.
This implementation returns an error if the window pointer is null, or
if scrolling is not enabled in the window, e.g., with scrollok.
NOTES
Note that scrl and scroll may be macros.
The SVr4 documentation says that the optimization of physically
scrolling immediately if the scroll region is the entire screen "is"
performed, not "may be" performed. This implementation 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 the SVr4 nor the XSI documentation specify whether the current
attribute or current color-pair of blanks generated by the scroll
function is zeroed. Under this implementation it is.
PORTABILITY
The XSI Curses standard, Issue 4 describes these functions.
SEE ALSOcurses(3), curs_outopts(3)
March 1, 2011
