xref: /dflybsd-src/lib/libc/locale/mblen.3 (revision c66c7e2fb8d0d28477d550f1d2a50c4677d547ff)

.\" Copyright (c) 2002-2004 Tim J. Robbins. All rights reserved.
.\" Copyright (c) 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Donn Seeley of BSDI.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" 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/mblen.3 165903 2007-01-09 00:28:16Z imp $
.\"
.Dd December 26, 2013
.Dt MBLEN 3
.Os
.Sh NAME
.Nm mblen ,
.Nm mblen_l
.Nd get number of bytes in a character
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In stdlib.h
.Ft int
.Fn mblen "const char *mbchar" "size_t nbytes"
.In xlocale.h
.Ft int
.Fn mblen_l "const char *mbchar" "size_t nbytes" "locale_t locale"
.Sh DESCRIPTION
The
.Fn mblen
and
.Fn mblen_l
functions compute the length in bytes
of a multibyte character
.Fa mbchar
according to a conversion state.
Up to
.Fa nbytes
bytes are examined.
.Pp
A call with a null
.Fa mbchar
pointer returns nonzero if the locale requires shift states,
zero otherwise;
if shift states are required, the shift state is reset to the initial state.
.Pp
The
.Fn mblen_l
function takes an explicit
.Fa locale
argument, whereas the
.Fn mblen
function uses the current global or per-thread locale.
.Sh RETURN VALUES
If
.Fa mbchar
is
.Dv NULL ,
the
.Fn mblen
and
.Fn mblen_l
functions return nonzero if shift states are supported,
zero otherwise.
.Pp
Otherwise, if
.Fa mbchar
is not a null pointer,
.Fn mblen
and
.Fn mblen_l
either return 0 if
.Fa mbchar
represents the null wide character, or return
the number of bytes processed in
.Fa mbchar ,
or return \-1 if no multibyte character
could be recognized or converted.
In this case,
.Fn mblen Ns 's
and
.Fn mblen_l Ns 's
internal conversion states are undefined.
.Sh ERRORS
The
.Fn mblen
and
.Fn mblen_l
functions 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 not valid.
.El
.Sh SEE ALSO
.Xr mbrlen 3 ,
.Xr mbtowc 3 ,
.Xr multibyte 3 ,
.Xr xlocale 3
.Sh STANDARDS
The
.Fn mblen
function conforms to
.St -isoC-99 .