1curs_clear(3X)                                                  curs_clear(3X)
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NAME

6       erase, werase, clear, wclear, clrtobot, wclrtobot, clrtoeol, wclrtoeol
7       - clear all or part of a curses window
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SYNOPSIS

10       # include <curses.h>
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12       int erase(void);
13       int werase(WINDOW *win);
14       int clear(void);
15       int wclear(WINDOW *win);
16       int clrtobot(void);
17       int wclrtobot(WINDOW *win);
18       int clrtoeol(void);
19       int wclrtoeol(WINDOW *win);
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DESCRIPTION

22       The erase and werase routines copy blanks to every position in the win‐
23       dow, clearing the screen.
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25       The  clear and wclear routines are like erase and werase, but they also
26       call clearok, so that the screen is cleared completely on the next call
27       to wrefresh for that window and repainted from scratch.
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29       The clrtobot and wclrtobot routines erase from the cursor to the end of
30       screen.  That is, they erase all lines below the cursor in the  window.
31       Also,  the  current  line  to  the  right  of the cursor, inclusive, is
32       erased.
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34       The clrtoeol and wclrtoeol routines erase the current line to the right
35       of the cursor, inclusive, to the end of the current line.
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37       Blanks created by erasure have the current background rendition (as set
38       by wbkgdset) merged into them.
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RETURN VALUE

41       All routines return the integer OK on success and ERR on failure.   The
42       SVr4.0  manual  says "or a non-negative integer if immedok is set", but
43       this appears to be an error.
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45       X/Open defines no error conditions.  In this implementation,  functions
46       using a window pointer parameter return an error if it is null.
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NOTES

49       Note  that  erase, werase, clear, wclear, clrtobot, and clrtoeol may be
50       macros.
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PORTABILITY

53       These functions are described in the XSI Curses standard, Issue 4.  The
54       standard  specifies  that  they return ERR on failure, but specifies no
55       error conditions.
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57       Some historic curses implementations had, as an  undocumented  feature,
58       the  ability  to  do the equivalent of clearok(..., 1) by saying touch‐
59       win(stdscr) or clear(stdscr).  This will not work under ncurses.
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61       This implementation, and others such as Solaris, sets the current posi‐
62       tion  to 0,0 after erasing via werase() and wclear().  That fact is not
63       documented in other implementations, and may not be true of implementa‐
64       tions which were not derived from SVr4 source.
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66       Not obvious from the description, most implementations clear the screen
67       after wclear even for a subwindow or derived window.   If  you  do  not
68       want to clear the screen during the next wrefresh, use werase instead.
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SEE ALSO

71       curses(3X), curs_outopts(3X), curs_refresh(3X), curs_variables(3X)
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75                                                                curs_clear(3X)
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