Libc-583.tar.gz

[apple/libc.git] / locale / wctomb.3

.\" Copyright (c) 2002-2004 Tim J. Robbins. All rights reserved.
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.\" From @(#)multibyte.3	8.1 (Berkeley) 6/4/93
.\" From FreeBSD: src/lib/libc/locale/multibyte.3,v 1.22 2003/11/08 03:23:11 tjr Exp
.\" $FreeBSD: src/lib/libc/locale/wctomb.3,v 1.3 2004/07/05 06:36:36 ru Exp $
.\"
.Dd April 8, 2004
.Dt WCTOMB 3
.Os
.Sh NAME
.Nm wctomb ,
.Nm wctomb_l
.Nd convert a wide-character code to a character
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In stdlib.h
.Ft int
.Fo wctomb
.Fa "char *s"
.Fa "wchar_t wchar"
.Fc
.In stdlib.h
.In xlocale.h
.Ft int
.Fo wctomb_l
.Fa "char *s"
.Fa "wchar_t wchar"
.Fa "locale_t loc"
.Fc
.Sh DESCRIPTION
The
.Fn wctomb
function converts a wide character,
.Fa wchar ,
into a multibyte character and stores the result in
.Fa s .
The object pointed to by
.Fa s
must be large enough to accommodate the multibyte character,
which may be up to
.Dv MB_LEN_MAX
bytes.
.Pp
A call with a null
.Fa s
pointer returns nonzero if the current locale requires shift states,
zero otherwise;
if shift states are required, the shift state is reset to the initial state.
.Pp
Although the
.Fn wctomb
function uses the current locale, the
.Fn wctomb_l
function may be passed a locale directly. See
.Xr xlocale 3
for more information.
.Sh RETURN VALUES
If
.Fa s
is
.Dv NULL ,
the
.Fn wctomb
function returns nonzero if shift states are supported,
zero otherwise.
If
.Fa s
is valid,
.Fn wctomb
returns
the number of bytes processed in
.Fa s ,
or \-1 if no multibyte character
could be recognized or converted.
In this case,
.Fn wctomb Ns 's
internal conversion state is undefined.
.Sh ERRORS
The
.Fn wctomb
function will fail if:
.Bl -tag -width Er
.It Bq Er EILSEQ
An invalid multibyte sequence was detected.
.It Bq Er EINVAL
The internal conversion state is invalid.
.El
.Sh SEE ALSO
.Xr mbtowc 3 ,
.Xr wcrtomb 3 ,
.Xr wcstombs 3 ,
.Xr wctob 3 ,
.Xr xlocale 3
.Sh STANDARDS
The
.Fn wctomb
function conforms to
.St -isoC-99 .