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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | PORTABILITY | SEE ALSO | COLOPHON |
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curs_clear(3X) Library calls curs_clear(3X)
erase, werase, clear, wclear, clrtobot, wclrtobot, clrtoeol,
wclrtoeol - clear all or part of a curses window
#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);
erase, werase
The erase and werase routines copy blanks to every position in the
window, clearing the screen.
Blanks created by erasure have the current background rendition
(as set by wbkgdset(3X)) merged into them.
clear, wclear
The clear and wclear routines are like erase and werase, but they
also call clearok(3X), so that the screen is cleared completely on
the next call to wrefresh for that window and repainted from
scratch.
clrtobot, wclrtobot
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,
inclusive, is erased.
clrtoeol, wclrtoeol
The clrtoeol and wclrtoeol routines erase the current line to the
right of the cursor, inclusive, to the end of the current line.
All routines return the integer OK on success and ERR on failure.
In this implementation,
• functions using a window pointer parameter return ERR if it is
null
• wclrtoeol returns an error if the cursor position is about to
wrap.
erase, werase, clear, wclear, clrtobot, and clrtoeol may be
implemented as macros.
X/Open Curses Issue 4 describes these functions. It specifies no
error conditions for them.
SVr4 documentation says that these functions return OK “or a non-
negative integer if immedok() is set”, referring to the return
value from wrefresh, which in SVr4 returns a count of characters
written to the window if its immedok property is set; in ncurses,
it does not.
Some historic curses implementations had, as an undocumented
feature, the ability to do the equivalent of clearok(..., 1) by
saying touchwin(stdscr) or clear(stdscr). This will not work
under ncurses.
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 subwindow or derived window. If
you do not want to clear the screen during the next wrefresh, use
werase instead.
curses(3X), curs_outopts(3X), curs_refresh(3X), curs_variables(3X)
This page is part of the ncurses (new curses) project.
Information about the project can be found at
⟨https://invisible-island.net/ncurses/ncurses.html⟩. If you have a
bug report for this manual page, send it to bug-ncurses@gnu.org.
This page was obtained from the tarball ncurses-6.6.tar.gz fetched
from ⟨https://ftp.gnu.org/gnu/ncurses/⟩ on 2026-01-16. If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for the
page, or you have corrections or improvements to the information
in this COLOPHON (which is not part of the original manual page),
send a mail to man-pages@man7.org
ncurses @NCURSES_MAJOR@.@NCU... 2025-01-18 curs_clear(3X)
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HTML rendering created 2026-01-16 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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