curs_bkgd()

NAME

bkgdset(), wbkgdset(), bkgd(), wbkgd() - curses window background manipulation routines

SYNOPSIS

#include <curses.h>


void bkgdset(const chtype ch);
void wbkgdset(WINDOW *win, const chtype ch);
int bkgd(const chtype ch);
int wbkgd(WINDOW *win, const chtype ch);
chtype wgetbkgd(WINDOW *win);

The bkgdset(3) and wbkgdset(3) routines manipulate the background of the named window. Background is a chtype consisting of any combination of attributes and a character. The attribute part of the background is combined (ORed) with all non-blank characters that are written into the window with waddch(3). Both the character and attribute parts of the background are combined with the blank characters. The background becomes a property of the character and moves with the character through any scrolling and insert/delete line/character operations. To the extent possible on a particular terminal, the attribute part of the background is displayed as the graphic rendition of the character put on the screen.

The bkgd(3) and wbkgd(3) routines combine the new background with every position in the window. Background is any combination of attributes and a character. Only the attribute part is used to set the background of non-blank characters, while both character and attributes are used for blank positions. To the extent possible on a particular terminal, the attribute part of the background is displayed as the graphic rendition of the character put on the screen.

The wgetbkgd() function returns the given window's current background character/attribute pair.

RETURN VALUE

The routines bkgd(3) and wbkgd(3) return the integer OK. The SVr4.0 manual says "or a non-negative integer if immedok(3) is set", but this appears to be an error.

NOTES

Note that bkgdset(3) and bkgd(3) may be macros.

PORTABILITY

These functions are described in the XSI Curses standard, Issue 4. The draft does not include const qualifiers on the arguments. The standard specifies that bkgd(3) and wbkgd(3) return ERR on failure, but gives no failure conditions. The draft describes the new function wgetbkgd(), which is not in SVr4.