curs_add_wch(3X) curs_add_wch(3X)


add_wch, wadd_wch, mvadd_wch, mvwadd_wch, echo_wchar, wecho_wchar - add a complex character and rendition to a curses window, then advance the cursor


#include <curses.h>
int add_wch( const cchar_t * wch );
int wadd_wch( WINDOW * win, const cchar_t * wch );
int mvadd_wch( int y, int x, const cchar_t * wch );
int mvwadd_wch( WINDOW * win, int y, int x, const cchar_t * wch );
int echo_wchar( const cchar_t * wch );
int wecho_wchar( WINDOW * win, const cchar_t * wch );


The add_wch, wadd_wch, mvadd_wch, and mvwadd_wch functions put the complex character wch into the given window at its current position, which is then advanced. These functions perform wrapping and special-character processing as follows:
If wch refers to a spacing character, then any previous character at that location is removed. A new character specified by wch is placed at that location with rendition specified by wch. The cursor then advances to the next spacing character on the screen.
If wch refers to a non-spacing character, all previous characters at that location are preserved. The non-spacing characters of wch are added to the spacing complex character, and the rendition specified by wch is ignored.
If the character part of wch is a tab, newline, backspace or other control character, the window is updated and the cursor moves as if addch were called.

The echo_wchar function is functionally equivalent to a call to add_wch followed by a call to refresh. Similarly, the wecho_wchar is functionally equivalent to a call to wadd_wch followed by a call to wrefresh. The knowledge that only a single character is being output is taken into consideration and, for non-control characters, a considerable performance gain might be seen by using the * echo* functions instead of their equivalents.


All routines return the integer ERR upon failure and OK on success.


Note that add_wch, mvadd_wch, mvwadd_wch, and echo_wchar may be macros.


All these functions are described in the XSI Curses standard, Issue 4. The defaults specified for forms-drawing characters apply in the POSIX locale.

XSI documents constants beginning with WACS_ which are used for line-drawing. Those are not currently implemented in ncurses.


curses(3X), curs_addch(3X), curs_attr(3X), curs_clear(3X), curs_outopts(3X), curs_refresh(3X), putwc(3)