curs_scroll 3x 2023-07-01 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

       The  scroll routine scrolls the window up one line.  This involves mov-
       ing 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 scrol-
       lok(3x).


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(3x).


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 func-
       tion is zeroed.  Under this implementation it is.


PORTABILITY

       The XSI Curses standard, Issue 4 describes these functions.


SEE ALSO

       curses(3x), curs_outopts(3x)



ncurses 6.4                       2023-07-01                   curs_scroll(3x)