.\"	$NetBSD: curses_cchar.3,v 1.2 2018/11/24 11:04:39 wiz Exp $
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.\" Copyright (c) 2018 Valery Ushakov
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.Dd November 19, 2018
.Dt CURSES_CCHAR 3
.Os
.Sh NAME
.Nm curses_cchar ,
.Nm getcchar ,
.Nm setcchar
.Nd curses representation of wide characters
.Sh LIBRARY
.Lb libcurses
.Sh SYNOPSIS
.\"
.In curses.h
.\"
.Ft int
.Fo getcchar
.Fa "const cchar_t *wcval"
.Fa "wchar_t *wch"
.Fa "attr_t *attrs"
.Fa "short *color_pair"
.Fa "void *opts"
.Fc
.\"
.Ft int
.Fo setcchar
.Fa "cchar_t *wcval"
.Fa "const wchar_t *wch"
.Fa "const attr_t attrs"
.Fa "short color_pair"
.Fa "const void *opts"
.Fc
.Sh DESCRIPTION
Curses uses the opaque type
.Vt cchar_t
to represent a string of wide characters up to an
implementation-dependent length along with a color pair and zero or
more attributes.
A null
.Vt cchar_t
object is an object that references an empty wide-character string.
Arrays of
.Vt cchar_t
objects are terminated by a null
.Vt cchar_t
object.
.Pp
Objects of type
.Vt cchar_t
can be manipulated using the
.Nm getcchar
and
.Nm setcchar
functions.
Both these functions take as their last parameter the
.Fa opts
argument which is reserved for future extensions.
Currently, the application must provide a null pointer as
.Fa opts .
.\"
.Pp
When the
.Nm getcchar
function is called with non-null
.Fa wch
it extracts the information from the
.Fa wcval
object.
The string of wide characters in
.Fa wcval
is copied to the
.Fa wch
array.
The attributes are stored in
.Fa attrs
and the color pair is stored in
.Fa color_pair .
In this case it returns
.Er OK
upon successful completion, and
.Er ERR
otherwise.
.Pp
When
.Nm getcchar
is called with null
.Fa wch
it doesn't store any information but returns the number of wide
characters referenced by
.Fa wcval ,
including the null terminator.
.\"
.Pp
.Nm setcchar
initializes
.Fa wcval
with the wide-character string
.Fa wch ,
attributes
.Fa attrs ,
and color pair
.Fa color_pair .
.Sh RETURN VALUES
.Nm getchar
called with null
.Fa wch
returns the the number of wide characters referenced by
.Fa wcval ,
including the null terminator.
.Pp
Otherwise these functions return one of the following values:
.Bl -tag -width "Er ERR" -compact
.It Er OK
The function completed successfully.
.It Er ERR
An error occurred in the function.
.El
.\" .Sh SEE ALSO
.\" XXX no other man pages yet for HAVE_WCHAR functions
.Sh STANDARDS
The
.Nx
Curses library complies with the X/Open Curses specification, part of
the Single Unix Specification.
.Sh HISTORY
The Curses package appeared in
.Bx 4.0 .
.Pp
Wide characters support appeared in
.Nx 5.0 .