* sale, use or other dealings in this Software without prior written *
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- * @Id: curs_bkgd.3x,v 1.49 2023/11/25 14:01:49 tom Exp @
+ * @Id: curs_bkgd.3x,v 1.51 2023/12/02 21:02:44 tom Exp @
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-<H1 class="no-header">curs_bkgd 3x 2023-11-25 ncurses 6.4 Library calls</H1>
+<H1 class="no-header">curs_bkgd 3x 2023-12-02 ncurses 6.4 Library calls</H1>
<PRE>
<STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>
way the rendition of characters on the screen is updated when <STRONG>bkgd</STRONG> or
<STRONG>wbkgd</STRONG> is used to change the background character.
- This implementation, like SVr4 curses, does not store the background
- and window attribute contributions to each cell separately. It updates
- the rendition by comparing the character, non-color attributes and
- colors contained in the background. For each cell in the window,
- whether or not it is blank:
+ <EM>ncurses</EM>, like SVr4 <EM>curses</EM>, does not store the background and window
+ attribute contributions to each cell separately. It updates the
+ rendition by comparing the character, non-color attributes and colors
+ contained in the background. For each cell in the window, whether or
+ not it is blank:
<STRONG>o</STRONG> The library first compares the <EM>character</EM>, and if it matches the
current character part of the background, it replaces that with the
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
- These functions are described in the XSI Curses standard, Issue 4. It
- specifies that <STRONG>bkgd</STRONG> and <STRONG>wbkgd</STRONG> return <STRONG>ERR</STRONG> on failure, but gives no
- failure conditions.
-
- The routines <STRONG>bkgd</STRONG> and <STRONG>wbkgd</STRONG> return the integer <STRONG>OK</STRONG>, unless the library
- has not been initialized.
+ Functions returning an <EM>int</EM> return <STRONG>OK</STRONG> on success. <STRONG>bkgd</STRONG> returns <STRONG>ERR</STRONG> if
+ the library has not been initialized. <STRONG>wbkgd</STRONG> and <STRONG>getbkgd</STRONG> return <STRONG>ERR</STRONG> if
+ the <EM>WINDOW</EM> pointer argument is null.
- In contrast, the SVr4.0 manual says <STRONG>bkgd</STRONG> and <STRONG>wbkgd</STRONG> may return <STRONG>OK</STRONG> "or a
- non-negative integer if <STRONG>immedok</STRONG> is set", which refers to the return
- value from <STRONG>wrefresh</STRONG> (used to implement the immediate repainting). The
- SVr4 curses <STRONG>wrefresh</STRONG> returns the number of characters written to the
- screen during the refresh. This implementation does not do that.
+ In contrast, the SVr4.0 manual says <STRONG>bkgd</STRONG> and <STRONG>wbkgd</STRONG> may return <STRONG>OK</STRONG> "or a
+ non-negative integer if <STRONG>immedok</STRONG> is set", which refers to the return
+ value from <STRONG>wrefresh</STRONG> (used to implement the immediate repainting). SVr4
+ <EM>curses</EM> <STRONG>wrefresh</STRONG> returns the number of characters written to the screen
+ during the refresh. <EM>ncurses</EM> does not do that.
</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
+ Unusually, there is no <STRONG>wgetbkgd</STRONG> function; <STRONG>getbkgd</STRONG> behaves as one would
+ expect <STRONG>wgetbkgd</STRONG> to, accepting a <EM>WINDOW</EM> pointer argument.
+
Note that <STRONG>bkgdset</STRONG> and <STRONG>bkgd</STRONG> may be macros.
X/Open Curses mentions that the character part of the background must
- be a single-byte value. This implementation, like SVr4, checks to
- ensure that, and will reuse the old background character if the check
- fails.
+ be a single-byte value. <EM>ncurses</EM>, like SVr4 <EM>curses</EM>, checks to ensure
+ that, and will reuse the old background character if the check fails.
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
- These functions are described in the XSI Curses standard, Issue 4.
+ These functions are described in the XSI Curses standard, Issue 4. It
+ specifies that <STRONG>bkgd</STRONG> and <STRONG>wbkgd</STRONG> return <STRONG>ERR</STRONG> on failure, but gives no
+ failure conditions.
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
-ncurses 6.4 2023-1
1-25 <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>
+ncurses 6.4 2023-1
2-02 <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>
</PRE>
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