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| <H1 class="no-header">curs_clear 3x</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> |
| |
| |
| |
| |
| </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 |
| |
| |
| </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE> |
| <STRONG>#</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>clear(void);</STRONG> |
| <STRONG>int</STRONG> <STRONG>wclear(WINDOW</STRONG> <STRONG>*win);</STRONG> |
| <STRONG>int</STRONG> <STRONG>clrtobot(void);</STRONG> |
| <STRONG>int</STRONG> <STRONG>wclrtobot(WINDOW</STRONG> <STRONG>*win);</STRONG> |
| <STRONG>int</STRONG> <STRONG>clrtoeol(void);</STRONG> |
| <STRONG>int</STRONG> <STRONG>wclrtoeol(WINDOW</STRONG> <STRONG>*win);</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. |
| |
| 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 |
| erased. |
| |
| 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. |
| |
| X/Open defines no error conditions. In this implementation, functions |
| using a window pointer parameter return an error if it is null. |
| |
| |
| </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE> |
| Note that <STRONG>erase</STRONG>, <STRONG>werase</STRONG>, <STRONG>clear</STRONG>, <STRONG>wclear</STRONG>, <STRONG>clrtobot</STRONG>, and <STRONG>clrtoeol</STRONG> may be |
| macros. |
| |
| |
| </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. |
| |
| 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. |
| |
| 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. |
| |
| 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 |
| want to clear the screen during the next <STRONG>wrefresh</STRONG>, use <STRONG>werase</STRONG> instead. |
| |
| |
| </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>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG> |
| |
| |
| |
| <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-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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