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+ * Copyright 2018,2020 Thomas E. Dickey *
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- * @Id: curs_clear.3x,v 1.15 2016/10/15 17:02:31 tom Exp @
+ * @Id: curs_clear.3x,v 1.20 2020/10/24 09:19:37 tom Exp @
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</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>
</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, functions
- using a window pointer parameter return an error if it is null.
+ X/Open defines no error conditions. In this implementation,
+
+ <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>
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>
+ The SVr4.0 manual says that these functions could return "a non-nega-
+ tive integer if <STRONG>immedok</STRONG> is set", referring to the return-value of <STRONG>wre-</STRONG>
+ <STRONG>fresh</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.
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-
+ 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
+ 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.
projects / ncurses.git / blobdiff