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-<H1 class="no-header">curs_clear 3x</H1>
+<H1 class="no-header">curs_clear 3x 2024-03-16 ncurses 6.4 Library calls</H1>
<PRE>
-<STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>
<STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>
+<STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>
Library calls <STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>
</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
- <STRONG>erase</STRONG>, <STRONG>werase</STRONG>, <STRONG>clear</STRONG>, <STRONG>wclear</STRONG>, <STRONG>clrtobot</STRONG>, <STRONG>wclrtobot</STRONG>, <STRONG>clrtoeol</STRONG>, <STRONG>wclrtoeol</STRONG>
- - clear all or part of a <STRONG>curses</STRONG> window
+ <STRONG>erase</STRONG>, <STRONG>werase</STRONG>, <STRONG>clear</STRONG>, <STRONG>wclear</STRONG>, <STRONG>clrtobot</STRONG>, <STRONG>wclrtobot</STRONG>, <STRONG>clrtoeol</STRONG>, <STRONG>wclrtoeol</STRONG>
+ - clear all or part of a <EM>curses</EM> window
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
- <STRONG>#</STRONG> <STRONG>include</STRONG> <STRONG><curses.h></STRONG>
+ <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
<STRONG>int</STRONG> <STRONG>erase(void);</STRONG>
- <STRONG>int</STRONG> <STRONG>werase(WINDOW</STRONG> <STRONG>*win);</STRONG>
+ <STRONG>int</STRONG> <STRONG>werase(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
+
<STRONG>int</STRONG> <STRONG>clear(void);</STRONG>
- <STRONG>int</STRONG> <STRONG>wclear(WINDOW</STRONG> <STRONG>*win);</STRONG>
+ <STRONG>int</STRONG> <STRONG>wclear(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
+
<STRONG>int</STRONG> <STRONG>clrtobot(void);</STRONG>
- <STRONG>int</STRONG> <STRONG>wclrtobot(WINDOW</STRONG> <STRONG>*win);</STRONG>
+ <STRONG>int</STRONG> <STRONG>wclrtobot(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
+
<STRONG>int</STRONG> <STRONG>clrtoeol(void);</STRONG>
- <STRONG>int</STRONG> <STRONG>wclrtoeol(WINDOW</STRONG> <STRONG>*win);</STRONG>
+ <STRONG>int</STRONG> <STRONG>wclrtoeol(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
- The <STRONG>erase</STRONG> and <STRONG>werase</STRONG> routines copy blanks to every position in the win-
- dow, clearing the screen.
- The <STRONG>clear</STRONG> and <STRONG>wclear</STRONG> routines are like <STRONG>erase</STRONG> and <STRONG>werase</STRONG>, but they also
- call <STRONG>clearok</STRONG>, so that the screen is cleared completely on the next call
- to <STRONG>wrefresh</STRONG> for that window and repainted from scratch.
+</PRE><H3><a name="h3-erase_werase">erase, werase</a></H3><PRE>
+ The <STRONG>erase</STRONG> and <STRONG>werase</STRONG> routines copy blanks to every position in the
+ window, clearing the screen.
+
+ Blanks created by erasure have the current background rendition (as set
+ by <STRONG><A HREF="curs_bkgd.3x.html">wbkgdset(3x)</A></STRONG>) merged into them.
+
+
+</PRE><H3><a name="h3-clear_wclear">clear, wclear</a></H3><PRE>
+ The <STRONG>clear</STRONG> and <STRONG>wclear</STRONG> routines are like <STRONG>erase</STRONG> and <STRONG>werase</STRONG>, but they also
+ call <STRONG><A HREF="curs_outopts.3x.html">clearok(3x)</A></STRONG>, so that the screen is cleared completely on the next
+ call to <STRONG>wrefresh</STRONG> for that window and repainted from scratch.
+
+</PRE><H3><a name="h3-clrtobot_wclrtobot">clrtobot, wclrtobot</a></H3><PRE>
The <STRONG>clrtobot</STRONG> and <STRONG>wclrtobot</STRONG> routines erase from the cursor to the end of
- screen. That is, they erase all lines below the cursor in the window.
- Also, the current line to the right of the cursor, inclusive, is
+ screen. That is, they erase all lines below the cursor in the window.
+ Also, the current line to the right of the cursor, inclusive, is
erased.
+
+</PRE><H3><a name="h3-clrtoeol_wclrtoeol">clrtoeol, wclrtoeol</a></H3><PRE>
The <STRONG>clrtoeol</STRONG> and <STRONG>wclrtoeol</STRONG> routines erase the current line to the right
of the cursor, inclusive, to the end of the current line.
- Blanks created by erasure have the current background rendition (as set
- by <STRONG>wbkgdset</STRONG>) merged into them.
-
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
- All routines return the integer <STRONG>OK</STRONG> on success and <STRONG>ERR</STRONG> on failure. The
- SVr4.0 manual says "or a non-negative integer if <STRONG>immedok</STRONG> is set", but
- this appears to be an error.
+ All routines return the integer <STRONG>OK</STRONG> on success and <STRONG>ERR</STRONG> on failure.
+
+ X/Open defines no error conditions. In this implementation,
- X/Open defines no error conditions. In this implementation, functions
- using a window pointer parameter return an error if it is null.
+ <STRONG>o</STRONG> functions using a window pointer parameter return an error if it is
+ null
+
+ <STRONG>o</STRONG> <STRONG>wclrtoeol</STRONG> returns an error if the cursor position is about to wrap.
</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
- These functions are described in the XSI Curses standard, Issue 4. The
- standard specifies that they return <STRONG>ERR</STRONG> on failure, but specifies no
- error conditions.
+ These functions are described in the XSI Curses standard, Issue 4.
+
+ The SVr4.0 manual says that these functions could return "or a non-
+ negative integer if <STRONG>immedok</STRONG> is set", referring to the return-value of
+ <STRONG>wrefresh</STRONG>. In that implementation, <STRONG>wrefresh</STRONG> would return a count of the
+ number of characters written to the terminal.
- Some historic curses implementations had, as an undocumented feature,
- the ability to do the equivalent of <STRONG>clearok(...,</STRONG> <STRONG>1)</STRONG> by saying <STRONG>touch-</STRONG>
- <STRONG>win(stdscr)</STRONG> or <STRONG>clear(stdscr)</STRONG>. This will not work under ncurses.
+ Some historic curses implementations had, as an undocumented feature,
+ the ability to do the equivalent of <STRONG>clearok(...,</STRONG> <STRONG>1)</STRONG> by saying
+ <STRONG>touchwin(stdscr)</STRONG> or <STRONG>clear(stdscr)</STRONG>. This will not work under <EM>ncurses</EM>.
- This implementation, and others such as Solaris, sets the current posi-
- tion to 0,0 after erasing via <STRONG>werase</STRONG> and <STRONG>wclear</STRONG>. That fact is not doc-
- umented in other implementations, and may not be true of implementa-
- tions which were not derived from SVr4 source.
+ This implementation, and others such as Solaris, sets the current
+ position to 0,0 after erasing via <STRONG>werase</STRONG> and <STRONG>wclear</STRONG>. That fact is not
+ documented in other implementations, and may not be true of
+ implementations which were not derived from SVr4 source.
Not obvious from the description, most implementations clear the screen
- after <STRONG>wclear</STRONG> even for a subwindow or derived window. If you do not
+ after <STRONG>wclear</STRONG> even for a subwindow or derived window. If you do not
want to clear the screen during the next <STRONG>wrefresh</STRONG>, use <STRONG>werase</STRONG> instead.
-
<STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>
+
ncurses 6.4 2024-03-16 <STRONG><A HREF="curs_clear.3x.html">curs_clear(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-DESCRIPTION">DESCRIPTION</a>
+<ul>
+<li><a href="#h3-erase_werase">erase, werase</a></li>
+<li><a href="#h3-clear_wclear">clear, wclear</a></li>
+<li><a href="#h3-clrtobot_wclrtobot">clrtobot, wclrtobot</a></li>
+<li><a href="#h3-clrtoeol_wclrtoeol">clrtoeol, wclrtoeol</a></li>
+</ul>
+</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>
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