lib/hz.h

   1 /*
   2  * Copyright (C) 1999-2000 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., 59 Temple Place -
  18  * Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 /*
  22  * HZ
  23  */
  24
  25 /* Specification: RFC 1842, RFC 1843 */
  26
  27 /*
  28  * The state is 1 in GB mode, 0 in ASCII mode.
  29  */
  30
  31 static int
  32 hz_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
  33 {
  34   state_t state = conv->istate;
  35   unsigned int count = 0;
  36   unsigned char c;
  37   for (;;) {
  38     c = *s;
  39     if (c == '~') {
  40       if (n < count+2)
  41         goto none;
  42       c = s[1];
  43       if (state == 0) {
  44         if (c == '~') {
  45           *pwc = (ucs4_t) '~';
  46           conv->istate = state;
  47           return count+2;
  48         }
  49         if (c == '{') {
  50           state = 1;
  51           s += 2; count += 2;
  52           if (n < count+1)
  53             goto none;
  54           continue;
  55         }
  56         if (c == '\n') {
  57           s += 2; count += 2;
  58           if (n < count+1)
  59             goto none;
  60           continue;
  61         }
  62       } else {
  63         if (c == '}') {
  64           state = 0;
  65           s += 2; count += 2;
  66           if (n < count+1)
  67             goto none;
  68           continue;
  69         }
  70       }
  71       return RET_ILSEQ;
  72     }
  73     break;
  74   }
  75   if (state == 0) {
  76     *pwc = (ucs4_t) c;
  77     conv->istate = state;
  78     return count+1;
  79   } else {
  80     int ret;
  81     if (n < count+2)
  82       goto none;
  83     ret = gb2312_mbtowc(conv,pwc,s,2);
  84     if (ret == RET_ILSEQ)
  85       return RET_ILSEQ;
  86     if (ret != 2) abort();
  87     conv->istate = state;
  88     return count+2;
  89   }
  90
  91 none:
  92   conv->istate = state;
  93   return RET_TOOFEW(count);
  94 }
  95
  96 static int
  97 hz_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
  98 {
  99   state_t state = conv->ostate;
 100   unsigned char buf[2];
 101   int ret;
 102
 103   /* Code set 0 (ASCII or GB 1988-89) */
 104   ret = ascii_wctomb(conv,buf,wc,1);
 105   if (ret != RET_ILSEQ) {
 106     if (ret != 1) abort();
 107     if (buf[0] < 0x80) {
 108       int count = (state ? 3 : 1);
 109       if (n < count)
 110         return RET_TOOSMALL;
 111       if (state) {
 112         r[0] = '~';
 113         r[1] = '}';
 114         r += 2;
 115         state = 0;
 116       }
 117       r[0] = buf[0];
 118       conv->ostate = state;
 119       return count;
 120     }
 121   }
 122
 123   /* Code set 1 (GB 2312-1980) */
 124   ret = gb2312_wctomb(conv,buf,wc,2);
 125   if (ret != RET_ILSEQ) {
 126     if (ret != 2) abort();
 127     if (buf[0] < 0x80 && buf[1] < 0x80) {
 128       int count = (state ? 2 : 4);
 129       if (n < count)
 130         return RET_TOOSMALL;
 131       if (!state) {
 132         r[0] = '~';
 133         r[1] = '{';
 134         r += 2;
 135         state = 1;
 136       }
 137       r[0] = buf[0];
 138       r[1] = buf[1];
 139       conv->ostate = state;
 140       return count;
 141     }
 142   }
 143
 144   return RET_ILSEQ;
 145 }
 146
 147 static int
 148 hz_reset (conv_t conv, unsigned char *r, int n)
 149 {
 150   state_t state = conv->ostate;
 151   if (state) {
 152     if (n < 2)
 153       return RET_TOOSMALL;
 154     r[0] = '~';
 155     r[1] = '}';
 156     /* conv->ostate = 0; will be done by the caller */
 157     return 2;
 158   } else
 159     return 0;
 160 }