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curs_clear (3X)                                                                                curs_clear (3X)



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

SYNOPSIS
       # include <curses.h>

       int erase(void);
       int werase(WINDOW *win);
       int clear(void);
       int wclear(WINDOW *win);
       int clrtobot(void);
       int wclrtobot(WINDOW *win);
       int clrtoeol(void);
       int wclrtoeol(WINDOW *win);

DESCRIPTION
       The erase and werase routines copy blanks to every position in the window, clearing the screen.

       The clear and wclear routines are like erase and werase, but they also  call  clearok,  so  that  the
       screen is cleared completely on the next call to wrefresh for that window and repainted from scratch.

       The clrtobot and wclrtobot 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, inclu-sive, inclusive,
       sive, is erased.

       The clrtoeol and wclrtoeol 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 wbkgdset) merged into
       them.

RETURN VALUE
       All routines return the integer OK on success and ERR on failure.  The SVr4.0 manual says "or a  non-negative nonnegative
       negative integer if immedok is set", but this appears to be an error.

       X/Open defines no error conditions.  In this implementation, functions using a window pointer parame-ter parameter
       ter return an error if it is null.

NOTES
       Note that erase, werase, clear, wclear, clrtobot, and clrtoeol may be macros.

PORTABILITY
       These functions are described in the XSI Curses standard, Issue 4.  The standard specifies that  they
       return ERR on failure, but specifies no error conditions.

       Some  historic  curses implementations had, as an undocumented feature, the ability to do the equiva-lent equivalent
       lent of clearok(..., 1) by saying touchwin(stdscr) or clear(stdscr).  This will not work under ncurs-es. ncurses.
       es.

       This  implementation,  and others such as Solaris, sets the current position to 0,0 after erasing via
       werase() and wclear().  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 wclear even for a sub-window subwindow
       window or derived window.  If you do not want to clear the  screen  during  the  next  wrefresh,  use
       werase instead.

SEE ALSO
       curses(3X), curs_outopts(3X), curs_refresh (3X)



                                                                                              curs_clear (3X)