140 lines
3.2 KiB
Groff
140 lines
3.2 KiB
Groff
.\" Copyright (c) 2002-2004 Tim J. Robbins
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" 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.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd April 8, 2004
|
|
.Dt MBRTOWC 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm mbrtowc
|
|
.Nd "convert a character to a wide-character code (restartable)"
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In wchar.h
|
|
.Ft size_t
|
|
.Fo mbrtowc
|
|
.Fa "wchar_t * restrict pwc" "const char * restrict s" "size_t n"
|
|
.Fa "mbstate_t * restrict ps"
|
|
.Fc
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn mbrtowc
|
|
function inspects at most
|
|
.Fa n
|
|
bytes pointed to by
|
|
.Fa s
|
|
to determine the number of bytes needed to complete the next multibyte
|
|
character.
|
|
If a character can be completed, and
|
|
.Fa pwc
|
|
is not
|
|
.Dv NULL ,
|
|
the wide character which is represented by
|
|
.Fa s
|
|
is stored in the
|
|
.Vt wchar_t
|
|
it points to.
|
|
.Pp
|
|
If
|
|
.Fa s
|
|
is
|
|
.Dv NULL ,
|
|
.Fn mbrtowc
|
|
behaves as if
|
|
.Fa pwc
|
|
was
|
|
.Dv NULL ,
|
|
.Fa s
|
|
was an empty string
|
|
.Pq Qq
|
|
and
|
|
.Fa n
|
|
was 1.
|
|
.Pp
|
|
The
|
|
.Vt mbstate_t
|
|
argument,
|
|
.Fa ps ,
|
|
is used to keep track of the shift state.
|
|
If it is
|
|
.Dv NULL ,
|
|
.Fn mbrtowc
|
|
uses an internal, static
|
|
.Vt mbstate_t
|
|
object, which is initialized to the initial conversion state
|
|
at program startup.
|
|
.Sh RETURN VALUES
|
|
The
|
|
.Fn mbrtowc
|
|
functions returns:
|
|
.Bl -tag -width indent
|
|
.It 0
|
|
The next
|
|
.Fa n
|
|
or fewer bytes
|
|
represent the null wide character
|
|
.Pq Li "L'\e0'" .
|
|
.It >0
|
|
The next
|
|
.Fa n
|
|
or fewer bytes
|
|
represent a valid character,
|
|
.Fn mbrtowc
|
|
returns the number of bytes used to complete the multibyte character.
|
|
.It Po Vt size_t Pc Ns \-2
|
|
The next
|
|
.Fa n
|
|
contribute to, but do not complete, a valid multibyte character sequence,
|
|
and all
|
|
.Fa n
|
|
bytes have been processed.
|
|
.It Po Vt size_t Pc Ns \-1
|
|
An encoding error has occurred.
|
|
The next
|
|
.Fa fn
|
|
or fewer bytes do not contribute to a valid multibyte character.
|
|
.El
|
|
.Sh ERRORS
|
|
The
|
|
.Fn mbrtowc
|
|
function will fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EILSEQ
|
|
An invalid multibyte sequence was detected.
|
|
.It Bq Er EINVAL
|
|
The conversion state is invalid.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr mbtowc 3 ,
|
|
.Xr multibyte 3 ,
|
|
.Xr setlocale 3 ,
|
|
.Xr wcrtomb 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn mbrtowc
|
|
function conforms to
|
|
.St -isoC-99 .
|