[apple/libc.git] / locale / FreeBSD / euc.5

.\" Copyright (c) 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Paul Borman at Krystal Technologies.
.\"
.\" 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.
.\" 4. 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.
.\"
.\"	@(#)euc.4	8.1 (Berkeley) 6/4/93
.\" $FreeBSD: src/lib/libc/locale/euc.5,v 1.13 2007/01/09 00:28:00 imp Exp $
.\"
.Dd November 8, 2003
.Dt EUC 5
.Os
.Sh NAME
.Nm euc
.Nd EUC encoding of wide characters
.Sh SYNOPSIS
.Nm ENCODING
.Qq EUC
.Pp
.Nm VARIABLE
.Ar len1
.Ar mask1
.Ar len2
.Ar mask2
.Ar len3
.Ar mask3
.Ar len4
.Ar mask4
.Ar mask
.Sh DESCRIPTION
.\"The
.\".Nm EUC
.\"encoding is provided for compatibility with
.\".Ux
.\"based systems.
.\"See
.\".Xr mklocale 1
.\"for a complete description of the
.\".Ev LC_CTYPE
.\"source file format.
.\".Pp
.Nm EUC
implements a system of 4 multibyte codesets.
A multibyte character in the first codeset consists of
.Ar len1
bytes starting with a byte in the range of 0x00 to 0x7f.
To allow use of
.Tn ASCII ,
.Ar len1
is always 1.
A multibyte character in the second codeset consists of
.Ar len2
bytes starting with a byte in the range of 0x80-0xff excluding 0x8e and 0x8f.
A multibyte character in the third codeset consists of
.Ar len3
bytes starting with the byte 0x8e.
A multibyte character in the fourth codeset consists of
.Ar len4
bytes starting with the byte 0x8f.
.Pp
The
.Vt wchar_t
encoding of
.Nm EUC
multibyte characters is dependent on the
.Ar len
and
.Ar mask
arguments.
First, the bytes are moved into a
.Vt wchar_t
as follows:
.Bd -literal
byte0 << ((\fIlen\fPN-1) * 8) | byte1 << ((\fIlen\fPN-2) * 8) | ... | byte\fIlen\fPN-1
.Ed
.Pp
The result is then ANDed with
.Ar ~mask
and ORed with
.Ar maskN .
Codesets 2 and 3 are special in that the leading byte (0x8e or 0x8f) is
first removed and the
.Ar lenN
argument is reduced by 1.
.Pp
For example, the
.Li ja_JP.eucJP
locale has the following
.Va VARIABLE
line:
.Bd -literal
VARIABLE	1 0x0000 2 0x8080 2 0x0080 3 0x8000 0x8080
.Ed
.Pp
Codeset 1 consists of the values 0x0000 - 0x007f.
.Pp
Codeset 2 consists of the values who have the bits 0x8080 set.
.Pp
Codeset 3 consists of the values 0x0080 - 0x00ff.
.Pp
Codeset 4 consists of the values 0x8000 - 0xff7f excluding the values
which have the 0x0080 bit set.
.Pp
Notice that the global
.Ar mask
is set to 0x8080, this implies that from those 2 bits the codeset can
be determined.
.Sh SEE ALSO
.Xr mklocale 1 ,
.Xr setlocale 3
Commit	Line	Data
5b2abdfb	1	.\" Copyright (c) 1993
e9ce8d39 A	2	.\" The Regents of the University of California. All rights reserved.
e9ce8d39 A	3	.\"
5b2abdfb A	4	.\" This code is derived from software contributed to Berkeley by
	5	.\" Paul Borman at Krystal Technologies.
	6	.\"
e9ce8d39 A	7	.\" Redistribution and use in source and binary forms, with or without
	8	.\" modification, are permitted provided that the following conditions
	9	.\" are met:
	10	.\" 1. Redistributions of source code must retain the above copyright
	11	.\" notice, this list of conditions and the following disclaimer.
	12	.\" 2. Redistributions in binary form must reproduce the above copyright
	13	.\" notice, this list of conditions and the following disclaimer in the
	14	.\" documentation and/or other materials provided with the distribution.
e9ce8d39 A	15	.\" 4. Neither the name of the University nor the names of its contributors
	16	.\" may be used to endorse or promote products derived from this software
	17	.\" without specific prior written permission.
	18	.\"
	19	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	20	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	21	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	22	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	23	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	24	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	25	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	26	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	27	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	28	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	29	.\" SUCH DAMAGE.
	30	.\"
3d9156a7	31	.\" @(#)euc.4 8.1 (Berkeley) 6/4/93
1f2f436a	32	.\" $FreeBSD: src/lib/libc/locale/euc.5,v 1.13 2007/01/09 00:28:00 imp Exp $
e9ce8d39	33	.\"
3d9156a7 A	34	.Dd November 8, 2003
3d9156a7 A	35	.Dt EUC 5
e9ce8d39 A	36	.Os
e9ce8d39 A	37	.Sh NAME
3d9156a7 A	38	.Nm euc
3d9156a7 A	39	.Nd EUC encoding of wide characters
e9ce8d39	40	.Sh SYNOPSIS
5b2abdfb	41	.Nm ENCODING
3d9156a7 A	42	.Qq EUC
	43	.Pp
	44	.Nm VARIABLE
	45	.Ar len1
	46	.Ar mask1
	47	.Ar len2
	48	.Ar mask2
	49	.Ar len3
	50	.Ar mask3
	51	.Ar len4
	52	.Ar mask4
	53	.Ar mask
e9ce8d39	54	.Sh DESCRIPTION
3d9156a7 A	55	.\"The
	56	.\".Nm EUC
	57	.\"encoding is provided for compatibility with
	58	.\".Ux
	59	.\"based systems.
	60	.\"See
	61	.\".Xr mklocale 1
	62	.\"for a complete description of the
	63	.\".Ev LC_CTYPE
	64	.\"source file format.
	65	.\".Pp
	66	.Nm EUC
	67	implements a system of 4 multibyte codesets.
	68	A multibyte character in the first codeset consists of
	69	.Ar len1
	70	bytes starting with a byte in the range of 0x00 to 0x7f.
	71	To allow use of
	72	.Tn ASCII ,
	73	.Ar len1
	74	is always 1.
	75	A multibyte character in the second codeset consists of
	76	.Ar len2
	77	bytes starting with a byte in the range of 0x80-0xff excluding 0x8e and 0x8f.
	78	A multibyte character in the third codeset consists of
	79	.Ar len3
	80	bytes starting with the byte 0x8e.
	81	A multibyte character in the fourth codeset consists of
	82	.Ar len4
	83	bytes starting with the byte 0x8f.
9385eb3d	84	.Pp
e9ce8d39	85	The
3d9156a7 A	86	.Vt wchar_t
	87	encoding of
	88	.Nm EUC
	89	multibyte characters is dependent on the
	90	.Ar len
	91	and
	92	.Ar mask
	93	arguments.
	94	First, the bytes are moved into a
	95	.Vt wchar_t
	96	as follows:
e9ce8d39	97	.Bd -literal
3d9156a7	98	byte0 << ((\fIlen\fPN-1) * 8) \| byte1 << ((\fIlen\fPN-2) * 8) \| ... \| byte\fIlen\fPN-1
e9ce8d39	99	.Ed
5b2abdfb	100	.Pp
3d9156a7 A	101	The result is then ANDed with
	102	.Ar ~mask
	103	and ORed with
	104	.Ar maskN .
	105	Codesets 2 and 3 are special in that the leading byte (0x8e or 0x8f) is
	106	first removed and the
	107	.Ar lenN
	108	argument is reduced by 1.
5b2abdfb	109	.Pp
3d9156a7 A	110	For example, the
	111	.Li ja_JP.eucJP
	112	locale has the following
	113	.Va VARIABLE
	114	line:
5b2abdfb	115	.Bd -literal
3d9156a7	116	VARIABLE 1 0x0000 2 0x8080 2 0x0080 3 0x8000 0x8080
5b2abdfb A	117	.Ed
5b2abdfb A	118	.Pp
3d9156a7 A	119	Codeset 1 consists of the values 0x0000 - 0x007f.
	120	.Pp
	121	Codeset 2 consists of the values who have the bits 0x8080 set.
	122	.Pp
	123	Codeset 3 consists of the values 0x0080 - 0x00ff.
	124	.Pp
	125	Codeset 4 consists of the values 0x8000 - 0xff7f excluding the values
	126	which have the 0x0080 bit set.
	127	.Pp
	128	Notice that the global
	129	.Ar mask
	130	is set to 0x8080, this implies that from those 2 bits the codeset can
	131	be determined.
	132	.Sh SEE ALSO
5b2abdfb	133	.Xr mklocale 1 ,
3d9156a7	134	.Xr setlocale 3