# curs_bkgrnd

## NAME



           **bkgrnd** , **wbkgrnd** , **bkgrndset** , **wbkgrndset** , **getbkgrnd** , **wgetbkgrnd** -
           **curses** window complex background manipulation routines
    


## SYNOPSIS



           **#include <curses.h>**
    
           **int bkgrnd( const cchar_t ***_wch_**);**
           **int wbkgrnd( WINDOW ***_win_**, const cchar_t ***_wch_**);**
    
           **void bkgrndset(const cchar_t ***_wch_ **);**
           **void wbkgrndset(WINDOW ***_win_**, const cchar_t ***_wch_**);**
    
           **int getbkgrnd(cchar_t ***_wch_**);**
           **int wgetbkgrnd(WINDOW ***_win_**, cchar_t ***_wch_**);**
    


## DESCRIPTION



       **bkgrndset**
           The **bkgrndset** and **wbkgrndset** routines manipulate the background of
           the named window.  The window background is a **cchar_t** consisting
           of any combination of attributes (i.e., rendition) and a complex
           character.
    
           •   The attribute part of the background is combined (OR'ed) with
               all non-blank characters that are written into the window with
               **waddch**.
    
           •   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.
    
       **bkgrnd**
           The **bkgrnd** and **wbkgrnd** functions set the background property of
           the current or specified window and then apply this setting to
           every character position in that window:
    
           •   The rendition of every character on the screen is changed to
               the new background rendition.
    
           •   Wherever the former background character appears, it is
               changed to the new background character.
    
       **getbkgrnd**
           The **getbkgrnd** function returns the given window's current
           background character/attribute pair via the **wch** pointer.  If the
           given window pointer is null, the character is not updated (but no
           error returned).
    


## NOTES



           Note that **bkgrnd** , **bkgrndset** , and **getbkgrnd** may be macros.
    
           X/Open Curses does not provide details on how the rendition is
           changed.  This implementation follows the approach used in SVr4
           curses, which is explained in the manual page for **wbkgd**.
    


## RETURN VALUE



           The **bkgrndset** and **wbkgrndset** routines do not return a value.
    
           Upon successful completion, the other functions return **OK**.
           Otherwise, they return **ERR** :
    
           •   A null window pointer is treated as an error.
    
           •   A null character pointer is treated as an error.
    


## PORTABILITY



           These functions are described in the XSI Curses standard, Issue 4
           (X/Open Curses).
    


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