.\" Copyright (c) 2002-2004 Tim J. Robbins. All rights reserved.
.\" Copyright (c) 1993
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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: head/lib/libc/locale/wcstombs.3 165903 2007-01-09 00:28:16Z imp $
.\"
.Dd December 27, 2013
.Dt WCSTOMBS 3
.Os
.Sh NAME
.Nm wcstombs ,
.Nm wcstombs_l
.Nd convert a wide-character string to a character string
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In stdlib.h
.Ft size_t
.Fo wcstombs
.Fa "char * restrict mbstring" "const wchar_t * restrict wcstring"
.Fa "size_t nbytes"
.Fc
.In xlocale.h
.Ft size_t
.Fo wcstombs_l
.Fa "char * restrict mbstring" "const wchar_t * restrict wcstring"
.Fa "size_t nbytes" "locale_t locale"
.Fc
.Sh DESCRIPTION
The
.Fn wcstombs
and
.Fn wcstombs_l
functions convert a wide character string
.Fa wcstring
into a multibyte character string,
.Fa mbstring ,
beginning in the initial conversion state.
Up to
.Fa nbytes
bytes are stored in
.Fa mbstring .
Partial multibyte characters at the end of the string are not stored.
The multibyte character string is null terminated if there is room.
.Pp
The
.Fn wcstombs_l
function takes an explicit
.Fa locale
argument, whereas the
.Fn wcstombs
function uses the current global or per-thread locale.
.Sh RETURN VALUES
The
.Fn wcstombs
and
.Fn wcstombs_l
functions return the number of bytes converted
(not including any terminating null), if successful, otherwise they return
.Po Vt size_t Pc Ns \-1 .
.Sh ERRORS
The
.Fn wcstombs
and
.Fn wcstombs_l
functions will fail if:
.Bl -tag -width Er
.It Bq Er EILSEQ
An invalid wide character was encountered.
.It Bq Er EINVAL
The conversion state is invalid.
.El
.Sh SEE ALSO
.Xr mbstowcs 3 ,
.Xr multibyte 3 ,
.Xr wcsrtombs 3 ,
.Xr wctomb 3 ,
.Xr xlocale 3
.Sh STANDARDS
The
.Fn wcstombs
function conforms to
.St -isoC-99 .