DOKK / manpages / debian 10 / ncurses-doc / setcchar.3ncurses.en
getcchar(3NCURSES) getcchar(3NCURSES)

getcchar, setcchar - Get a wide character string and rendition from a cchar_t or set a cchar_t from a wide-character string

#include <curses.h>

int getcchar(
const cchar_t *wcval,
wchar_t *wch,
attr_t *attrs,
short *color_pair,
void *opts );

int setcchar(
cchar_t *wcval,
const wchar_t *wch,
const attr_t attrs,
short color_pair,
void *opts );

The getcchar function gets a wide-character string and rendition from a cchar_t argument. When wch is not a null pointer, the getcchar function does the following:

  • Extracts information from a cchar_t value wcval
  • Stores the character attributes in the location pointed to by attrs
  • Stores the color-pair in the location pointed to by color_pair
  • Stores the wide-character string, characters referenced by wcval, into the array pointed to by wch.

When wch is a null pointer, the getcchar function does the following:

  • Obtains the number of wide characters pointed to by wcval
  • Does not change the data referenced by attrs or color_pair

The setcchar function initializes the location pointed to by wcval by using:

  • The character attributes in attrs
  • The color pair in color_pair
  • The wide-character string pointed to by wch. The string must be L'\0' terminated, contain at most one spacing character, which must be the first.
Up to CCHARW_MAX-1 nonspacing characters may follow. Additional nonspacing characters are ignored.
The string may contain a single control character instead. In that case, no nonspacing characters are allowed.

X/Open Curses documents the opts argument as reserved for future use, saying that it must be null. This implementation uses that parameter in ABI 6 for the functions which have a color-pair parameter to support extended color pairs:

  • For functions which modify the color, e.g., setcchar, if opts is set it is treated as a pointer to int, and used to set the color pair instead of the short pair parameter.
  • For functions which retrieve the color, e.g., getcchar, if opts is set it is treated as a pointer to int, and used to retrieve the color pair as an int value, in addition retrieving it via the standard pointer to short parameter.

The wcval argument may be a value generated by a call to setcchar or by a function that has a cchar_t output argument. If wcval is constructed by any other means, the effect is unspecified.

When wch is a null pointer, getcchar returns the number of wide characters referenced by wcval, including one for a trailing null.

When wch is not a null pointer, getcchar returns OK upon successful completion, and ERR otherwise.

Upon successful completion, setcchar returns OK. Otherwise, it returns ERR.

Functions: attr(3NCURSES), color(3NCURSES), ncurses(3NCURSES), wcwidth(3).