release/src/router/libiconv/lib/cp936.h

   1 /*
   2  * Copyright (C) 2005 Free Software Foundation, Inc.
   3  * This file is part of the GNU LIBICONV Library.
   4  *
   5  * The GNU LIBICONV Library is free software; you can redistribute it
   6  * and/or modify it under the terms of the GNU Library General Public
   7  * License as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * The GNU LIBICONV Library is distributed in the hope that it will be
  11  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Library General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Library General Public
  16  * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
  17  * If not, write to the Free Software Foundation, Inc., 51 Franklin Street,
  18  * Fifth Floor, Boston, MA 02110-1301, USA.
  19  */
  20
  21 /*
  22  * CP936
  23  */
  24
  25 /*
  26  * The IANA has CP936 as an alias of GBK. But GBK is an official Chinese
  27  * specification, whereas CP936 is de-facto maintained by Microsoft. And,
  28  * of course, Microsoft modified CP936 since 1999.
  29  *
  30  * The differences from GBK are:
  31  *
  32  * 1. A single character:
  33  *
  34  *    code   CP936.TXT
  35  *    0x80   0x20AC # EURO SIGN
  36  *
  37  * Some variants of CP936 (in JDK, Windows-2000, ICU) also add:
  38  *
  39  * 2. Private area mappings:
  40  *
  41  *              code                 Unicode
  42  *    0x{A1..A2}{40..7E,80..A0}  U+E4C6..U+E585
  43  *    0x{AA..AF,F8..FE}{A1..FE}  U+E000..U+E4C5
  44  *
  45  * We add them too because, although there are backward compatibility problems
  46  * when a character from a private area is moved to an official Unicode code
  47  * point, they are useful for some people in practice.
  48  */
  49
  50 static int
  51 cp936_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
  52 {
  53   /* Try GBK first. */
  54   {
  55     int ret = ces_gbk_mbtowc(conv,pwc,s,n);
  56     if (ret != RET_ILSEQ)
  57       return ret;
  58   }
  59   /* Then handle the additional mappings. */
  60   {
  61     unsigned char c = *s;
  62     if (c == 0x80) {
  63       *pwc = 0x20ac;
  64       return 1;
  65     }
  66     /* User-defined characters */
  67     if (c >= 0xa1 && c <= 0xa2) {
  68       if (n < 2)
  69         return RET_TOOFEW(0);
  70       {
  71         unsigned char c2 = s[1];
  72         if ((c2 >= 0x40 && c2 < 0x7f) || (c2 >= 0x80 && c2 < 0xa1)) {
  73           *pwc = 0xe4c6 + 96 * (c - 0xa1) + (c2 - (c2 >= 0x80 ? 0x41 : 0x40));
  74           return 2;
  75         }
  76       }
  77     } else if ((c >= 0xaa && c < 0xb0) || (c >= 0xf8 && c < 0xff)) {
  78       if (n < 2)
  79         return RET_TOOFEW(0);
  80       {
  81         unsigned char c2 = s[1];
  82         if (c2 >= 0xa1 && c2 < 0xff) {
  83           *pwc = 0xe000 + 94 * (c - (c >= 0xf8 ? 0xf2 : 0xaa)) + (c2 - 0xa1);
  84           return 2;
  85         }
  86       }
  87     }
  88   }
  89   return RET_ILSEQ;
  90 }
  91
  92 static int
  93 cp936_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
  94 {
  95   /* Try GBK first. */
  96   {
  97     int ret = ces_gbk_wctomb(conv,r,wc,n);
  98     if (ret != RET_ILUNI)
  99       return ret;
 100   }
 101   /* Then handle the additional mappings. */
 102   if (wc >= 0xe000 && wc < 0xe586) {
 103     /* User-defined characters */
 104     if (n < 2)
 105       return RET_TOOFEW(0);
 106     if (wc < 0xe4c6) {
 107       unsigned int i = wc - 0xe000;
 108       unsigned int c1 = i / 94;
 109       unsigned int c2 = i % 94;
 110       r[0] = c1 + (c1 < 6 ? 0xaa : 0xf2);
 111       r[1] = c2 + 0xa1;
 112       return 2;
 113     } else {
 114       unsigned int i = wc - 0xe4c6;
 115       unsigned int c1 = i / 96;
 116       unsigned int c2 = i % 96;
 117       r[0] = c1 + 0xa1;
 118       r[1] = c2 + (c2 < 0x3f ? 0x40 : 0x41);
 119       return 2;
 120     }
 121   } else if (wc == 0x20ac) {
 122     r[0] = 0x80;
 123     return 1;
 124   }
 125   return RET_ILUNI;
 126 }