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33 <HEAD>
34 <TITLE>curs_clear 3x</TITLE>
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39 <H1>curs_clear 3x</H1>
40 <HR>
41 <PRE>
42 <!-- Manpage converted by man2html 3.0.1 -->
43 <STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>                                           <STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>
44
45
46
47
48 </PRE>
49 <H2>NAME</H2><PRE>
50        <STRONG>erase</STRONG>, <STRONG>werase</STRONG>, <STRONG>clear</STRONG>, <STRONG>wclear</STRONG>, <STRONG>clrtobot</STRONG>, <STRONG>wclrtobot</STRONG>,
51        <STRONG>clrtoeol</STRONG>, <STRONG>wclrtoeol</STRONG> - clear all or part of a <STRONG>curses</STRONG> window
52
53
54 </PRE>
55 <H2>SYNOPSIS</H2><PRE>
56        <STRONG>#</STRONG> <STRONG>include</STRONG> <STRONG>&lt;curses.h&gt;</STRONG>
57
58        <STRONG>int</STRONG> <STRONG>erase(void);</STRONG>
59        <STRONG>int</STRONG> <STRONG>werase(WINDOW</STRONG> <STRONG>*win);</STRONG>
60        <STRONG>int</STRONG> <STRONG>clear(void);</STRONG>
61        <STRONG>int</STRONG> <STRONG>wclear(WINDOW</STRONG> <STRONG>*win);</STRONG>
62        <STRONG>int</STRONG> <STRONG>clrtobot(void);</STRONG>
63        <STRONG>int</STRONG> <STRONG>wclrtobot(WINDOW</STRONG> <STRONG>*win);</STRONG>
64        <STRONG>int</STRONG> <STRONG>clrtoeol(void);</STRONG>
65        <STRONG>int</STRONG> <STRONG>wclrtoeol(WINDOW</STRONG> <STRONG>*win);</STRONG>
66
67
68 </PRE>
69 <H2>DESCRIPTION</H2><PRE>
70        The  <STRONG>erase</STRONG>  and <STRONG>werase</STRONG> routines copy blanks to every posi-
71        tion in the window, clearing the screen.
72
73        The <STRONG>clear</STRONG> and <STRONG>wclear</STRONG> routines are like <STRONG>erase</STRONG>  and  <STRONG>werase</STRONG>,
74        but  they also call <STRONG>clearok</STRONG>, so that the screen is cleared
75        completely on the next call to <STRONG>wrefresh</STRONG>  for  that  window
76        and repainted from scratch.
77
78        The  <STRONG>clrtobot</STRONG> and <STRONG>wclrtobot</STRONG> routines erase from the cursor
79        to the end of screen.  That is, they erase all lines below
80        the  cursor  in the window.  Also, the current line to the
81        right of the cursor, inclusive, is erased.
82
83        The <STRONG>clrtoeol</STRONG> and <STRONG>wclrtoeol</STRONG> routines erase the current line
84        to  the  right of the cursor, inclusive, to the end of the
85        current line.
86
87        Blanks created by erasure have the current background ren-
88        dition (as set by <STRONG>wbkgdset</STRONG>) merged into them.
89
90
91 </PRE>
92 <H2>RETURN VALUE</H2><PRE>
93        All  routines  return the integer <STRONG>OK</STRONG> on success and <STRONG>ERR</STRONG> on
94        failure.  The SVr4.0 manual says "or a non-negative  inte-
95        ger if <STRONG>immedok</STRONG> is set", but this appears to be an error.
96
97        X/Open  defines  no error conditions.  In this implementa-
98        tion, functions using a window pointer parameter return an
99        error if it is null.
100
101
102 </PRE>
103 <H2>NOTES</H2><PRE>
104        Note that <STRONG>erase</STRONG>, <STRONG>werase</STRONG>, <STRONG>clear</STRONG>, <STRONG>wclear</STRONG>, <STRONG>clrtobot</STRONG>, and <STRONG>clr-</STRONG>
105        <STRONG>toeol</STRONG> may be macros.
106
107
108 </PRE>
109 <H2>PORTABILITY</H2><PRE>
110        These functions are described in the XSI Curses  standard,
111        Issue  4.   The standard specifies that they return <STRONG>ERR</STRONG> on
112        failure, but specifies no error conditions.
113
114        Some historic curses implementations had,  as  an  undocu-
115        mented  feature,  the  ability  to  do  the  equivalent of
116        <STRONG>clearok(...,</STRONG> <STRONG>1)</STRONG> by saying <STRONG>touchwin(stdscr)</STRONG>  or  <STRONG>clear(std-</STRONG>
117        <STRONG>scr)</STRONG>.  This will not work under ncurses.
118
119        This  implementation, and others such as Solaris, sets the
120        current position to 0,0 after  erasing  via  <STRONG>werase()</STRONG>  and
121        <STRONG>wclear()</STRONG>.   That fact is not documented in other implemen-
122        tations, and may not be true of implementations which were
123        not derived from SVr4 source.
124
125
126 </PRE>
127 <H2>SEE ALSO</H2><PRE>
128        <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>
129
130
131
132                                                          <STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>
133 </PRE>
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