Blame - doc/html/man/curs_clear.3x.html - android_external_libncurses

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<TITLE>curs_clear 3x</TITLE>

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<H1>curs_clear 3x</H1>

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<HR>

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<PRE>

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<A HREF="curs_clear.3x.html">curs_clear(3x)</A> <A HREF="curs_clear.3x.html">curs_clear(3x)</A>

</PRE>

erase, werase, clear, wclear, clrtobot, wclrtobot,

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clrtoeol, wclrtoeol - clear all or part of a curses window

</PRE>

<H2>SYNOPSIS</H2><PRE>

# include <curses.h>

int erase(void);

int werase(WINDOW *win);

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int clear(void);

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int wclear(WINDOW *win);

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int clrtobot(void);

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int wclrtobot(WINDOW *win);

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int clrtoeol(void);

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int wclrtoeol(WINDOW *win);

</PRE>

<H2>DESCRIPTION</H2><PRE>

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The erase and werase routines copy blanks to every posi-

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tion in the window, clearing the screen.

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The clear and wclear routines are like erase and werase,

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but they also call clearok, so that the screen is cleared

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completely on the next call to wrefresh for that window

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and repainted from scratch.

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The clrtobot and wclrtobot routines erase from the cursor

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to the end of screen. That is, they erase all lines below

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the cursor in the window. Also, the current line to the

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right of the cursor, inclusive, is erased.

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The clrtoeol and wclrtoeol routines erase the current line

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to the right of the cursor, inclusive, to the end of the

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current line.

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Blanks created by erasure have the current background ren-

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dition (as set by wbkgdset) merged into them.

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<H2>RETURN VALUE</H2><PRE>

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All routines return the integer OK on success and ERR on

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failure. The SVr4.0 manual says "or a non-negative inte-

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ger if immedok is set", but this appears to be an error.

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X/Open defines no error conditions. In this implementa-

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tion, functions using a window pointer parameter return an

error if it is null.

</PRE>

<H2>NOTES</H2><PRE>

Note that erase, werase, clear, wclear, clrtobot, and clr-

toeol may be macros.

</PRE>

<H2>PORTABILITY</H2><PRE>

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These functions are described in the XSI Curses standard,

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Issue 4. The standard specifies that they return ERR on

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failure, but specifies no error conditions.

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Some historic curses implementations had, as an undocu-

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mented feature, the ability to do the equivalent of

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clearok(..., 1) by saying touchwin(stdscr) or clear(std-

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scr). This will not work under ncurses.

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This implementation, and others such as Solaris, sets the

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current position to 0,0 after erasing via werase() and

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wclear(). That fact is not documented in other implemen-

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tations, and may not be true of implementations which were

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not derived from SVr4 source.

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Not obvious from the description, most implementations

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clear the screen after wclear even for a subwindow or de-

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rived window. If you do not want to clear the screen dur-

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ing the next wrefresh, use werase instead.

</PRE>

<A HREF="ncurses.3x.html">curses(3x)</A>, <A HREF="curs_outopts.3x.html">curs_outopts(3x)</A>, <A HREF="curs_refresh.3x.html">curs_refresh(3x)</A>

<A HREF="curs_clear.3x.html">curs_clear(3x)</A>

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Man(1) output converted with

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