1.\" Copyright (c) 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Paul Borman at Krystal Technologies. 6.\" 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. 15.\" 3. 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.\" 31.\" @(#)euc.4 8.1 (Berkeley) 6/4/93 32.\" 33.Dd September 9, 2019 34.Dt EUC 5 35.Os 36.Sh NAME 37.Nm euc 38.Nd EUC encoding of wide characters 39.Sh SYNOPSIS 40.Nm ENCODING 41.Qq EUC 42.Pp 43.Nm VARIABLE 44.Ar len1 45.Ar mask1 46.Ar len2 47.Ar mask2 48.Ar len3 49.Ar mask3 50.Ar len4 51.Ar mask4 52.Ar mask 53.Sh DESCRIPTION 54.\"The 55.\".Nm EUC 56.\"encoding is provided for compatibility with 57.\".Ux 58.\"based systems. 59.\"See 60.\".Xr localedef 1 61.\"for a complete description of the 62.\".Ev LC_CTYPE 63.\"source file format. 64.\".Pp 65.Nm EUC 66implements a system of 4 multibyte codesets. 67A multibyte character in the first codeset consists of 68.Ar len1 69bytes starting with a byte in the range of 0x00 to 0x7f. 70To allow use of 71.Tn ASCII , 72.Ar len1 73is always 1. 74A multibyte character in the second codeset consists of 75.Ar len2 76bytes starting with a byte in the range of 0x80-0xff excluding 0x8e and 0x8f. 77A multibyte character in the third codeset consists of 78.Ar len3 79bytes starting with the byte 0x8e. 80A multibyte character in the fourth codeset consists of 81.Ar len4 82bytes starting with the byte 0x8f. 83.Pp 84The 85.Vt wchar_t 86encoding of 87.Nm EUC 88multibyte characters is dependent on the 89.Ar len 90and 91.Ar mask 92arguments. 93First, the bytes are moved into a 94.Vt wchar_t 95as follows: 96.Bd -literal 97byte0 << ((\fIlen\fPN-1) * 8) | byte1 << ((\fIlen\fPN-2) * 8) | ... | byte\fIlen\fPN-1 98.Ed 99.Pp 100The result is then ANDed with 101.Ar ~mask 102and ORed with 103.Ar maskN . 104Codesets 2 and 3 are special in that the leading byte (0x8e or 0x8f) is 105first removed and the 106.Ar lenN 107argument is reduced by 1. 108.Pp 109For example, the 110.Li ja_JP.eucJP 111locale has the following 112.Va VARIABLE 113line: 114.Bd -literal 115VARIABLE 1 0x0000 2 0x8080 2 0x0080 3 0x8000 0x8080 116.Ed 117.Pp 118Codeset 1 consists of the values 0x0000 - 0x007f. 119.Pp 120Codeset 2 consists of the values who have the bits 0x8080 set. 121.Pp 122Codeset 3 consists of the values 0x0080 - 0x00ff. 123.Pp 124Codeset 4 consists of the values 0x8000 - 0xff7f excluding the values 125which have the 0x0080 bit set. 126.Pp 127Notice that the global 128.Ar mask 129is set to 0x8080, this implies that from those 2 bits the codeset can 130be determined. 131.Sh SEE ALSO 132.Xr localedef 1 , 133.Xr setlocale 3 134