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* @Id: curs_scroll.3x,v 1.43 2024/04/20 18:54:36 tom Exp @
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<H1 class="no-header">curs_scroll 3x 2024-04-20 ncurses 6.5 Library calls</H1>
<PRE>
<STRONG><A HREF="curs_scroll.3x.html">curs_scroll(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_scroll.3x.html">curs_scroll(3x)</A></STRONG>
</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
<STRONG>scroll</STRONG>, <STRONG>scrl</STRONG>, <STRONG>wscrl</STRONG> - scroll a <EM>curses</EM> window
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
<STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
<STRONG>int</STRONG> <STRONG>scroll(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>scrl(int</STRONG> <EM>n</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>wscrl(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>n</EM><STRONG>);</STRONG>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
<STRONG>scroll</STRONG> scrolls the given window up one line. That is, every visible
line we might number <EM>i</EM> becomes line <EM>i</EM>-1. The text of the top line in
the window disappears and the bottom line is populated with blank
characters; see <STRONG><A HREF="curs_bkgd.3x.html">bkgd(3x)</A></STRONG> or <STRONG><A HREF="curs_bkgrnd.3x.html">bkgrnd(3x)</A></STRONG>. 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 <STRONG><A HREF="curs_variables.3x.html">curscr(3x)</A></STRONG>.
<STRONG>scrl</STRONG> and <STRONG>wscrl</STRONG> scroll <STRONG>stdscr</STRONG> or the specified window up or down
depending on the sign of <EM>n</EM>.
<STRONG>o</STRONG> For positive <EM>n</EM>, line <EM>i</EM>+<EM>n</EM> becomes <EM>i</EM> (scrolling up);
<STRONG>o</STRONG> for negative <EM>n</EM>, line <EM>i</EM>-<EM>n</EM> becomes <EM>i</EM> (scrolling down).
The cursor does not move. These functions perform no operation unless
scrolling is enabled for the window via <STRONG><A HREF="scrollok.3x.html">scrollok(3x)</A></STRONG>.
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
These functions return <STRONG>ERR</STRONG> upon failure and <STRONG>OK</STRONG> upon success.
<EM>ncurses</EM> returns <STRONG>ERR</STRONG> if scrolling is not enabled in the window, for
example with <STRONG><A HREF="scrollok.3x.html">scrollok(3x)</A></STRONG>, or if the <EM>WINDOW</EM> pointer is null.
</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
Unusually, there is no <STRONG>wscroll</STRONG> function; <STRONG>scroll</STRONG> behaves as one would
expect <STRONG>wscroll</STRONG> to, accepting a <EM>WINDOW</EM> pointer argument.
<STRONG>scrl</STRONG> and <STRONG>scroll</STRONG> may be implemented as macros.
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
X/Open Curses, Issue 4 describes these functions. It defines no error
conditions.
SVr4 specifies only "an integer value other than <STRONG>ERR</STRONG>" 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. <EM>ncurses</EM> 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 <EM>curses</EM> nor X/Open Curses specify whether the current
attribute or current color pair of blanks generated by the scroll
function are zeroed. <EM>ncurses</EM> does so.
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
<STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>
ncurses 6.5 2024-04-20 <STRONG><A HREF="curs_scroll.3x.html">curs_scroll(3x)</A></STRONG>
</PRE>
<div class="nav">
<ul>
<li><a href="#h2-NAME">NAME</a></li>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
<li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
<li><a href="#h2-NOTES">NOTES</a></li>
<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
</ul>
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