src/charsets.c

   1 /* Text conversion from one charset to another.
   2
   3    Copyright (C) 2001 Walery Studennikov <despair@sama.ru>
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  */
  19
  20 /** \file charsets.c
  21  *  \brief Source: Text conversion from one charset to another
  22  */
  23
  24 #include <config.h>
  25
  26 #ifdef HAVE_CHARSET
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31
  32 #include "global.h"
  33 #include "charsets.h"
  34 #include "strutil.h"            /* utf-8 functions */
  35 #include "main.h"
  36 #include "util.h"               /* concat_dir_and_file() */
  37 #include "fileloc.h"
  38
  39 int n_codepages = 0;
  40
  41 struct codepage_desc *codepages;
  42
  43 unsigned char conv_displ[256];
  44 unsigned char conv_input[256];
  45
  46 const char *cp_display = NULL;
  47 const char *cp_source = NULL;
  48
  49
  50 int
  51 load_codepages_list (void)
  52 {
  53     int result = -1;
  54     FILE *f;
  55     char *fname;
  56     char buf[BUF_MEDIUM];
  57     char *default_codepage = NULL;
  58
  59     fname = concat_dir_and_file (mc_home, CHARSETS_INDEX);
  60     if (!(f = fopen (fname, "r"))) {
  61         fprintf (stderr, _("Warning: file %s not found\n"), fname);
  62         g_free (fname);
  63
  64         fname = concat_dir_and_file (mc_home_alt, CHARSETS_INDEX);
  65         if (!(f = fopen (fname, "r"))) {
  66             fprintf (stderr, _("Warning: file %s not found\n"), fname);
  67             g_free (fname);
  68
  69             /* file is not found, add defaullt codepage */
  70             n_codepages = 1;
  71             codepages = g_new0 (struct codepage_desc, n_codepages + 1);
  72             codepages[0].id = g_strdup ("ASCII");
  73             codepages[0].name = g_strdup (_("7-bit ASCII"));
  74             return n_codepages;
  75         }
  76     }
  77     g_free (fname);
  78
  79     for (n_codepages = 0; fgets (buf, sizeof (buf), f);)
  80         if (buf[0] != '\n' && buf[0] != '\0' && buf[0] != '#')
  81             ++n_codepages;
  82     rewind (f);
  83
  84     codepages = g_new0 (struct codepage_desc, n_codepages + 1);
  85
  86     for (n_codepages = 0; fgets (buf, sizeof buf, f);) {
  87         /* split string into id and cpname */
  88         char *p = buf;
  89         size_t buflen = strlen (buf);
  90
  91         if (*p == '\n' || *p == '\0' || *p == '#')
  92             continue;
  93
  94         if (buflen > 0 && buf[buflen - 1] == '\n')
  95             buf[buflen - 1] = '\0';
  96         while (*p != '\t' && *p != ' ' && *p != '\0')
  97             ++p;
  98         if (*p == '\0')
  99             goto fail;
 100
 101         *p++ = '\0';
 102         g_strstrip (p);
 103         if (*p == '\0')
 104             goto fail;
 105
 106         if (strcmp (buf, "default") == 0)
 107             default_codepage = g_strdup (p);
 108         else {
 109             codepages[n_codepages].id = g_strdup (buf);
 110             codepages[n_codepages].name = g_strdup (p);
 111             ++n_codepages;
 112         }
 113     }
 114
 115     if (default_codepage != NULL) {
 116         display_codepage = get_codepage_index (default_codepage);
 117         g_free (default_codepage);
 118     }
 119
 120     result = n_codepages;
 121   fail:
 122     fclose (f);
 123     return result;
 124 }
 125
 126 void
 127 free_codepages_list (void)
 128 {
 129     if (n_codepages > 0) {
 130         int i;
 131         for (i = 0; i < n_codepages; i++) {
 132             g_free (codepages[i].id);
 133             g_free (codepages[i].name);
 134         }
 135         n_codepages = 0;
 136         g_free (codepages);
 137         codepages = 0;
 138     }
 139 }
 140
 141 #define OTHER_8BIT "Other_8_bit"
 142
 143 const char *
 144 get_codepage_id (const int n)
 145 {
 146     return (n < 0) ? OTHER_8BIT : codepages[n].id;
 147 }
 148
 149 int
 150 get_codepage_index (const char *id)
 151 {
 152     int i;
 153     if (strcmp (id, OTHER_8BIT) == 0)
 154         return -1;
 155     if (codepages == NULL)
 156         return -1;
 157     for (i = 0; i < n_codepages; i++)
 158         if (strcmp (id, codepages[i].id) == 0)
 159             return i;
 160     return -1;
 161 }
 162
 163 static char
 164 translate_character (GIConv cd, char c)
 165 {
 166     gchar *tmp_buff = NULL;
 167     gsize bytes_read, bytes_written = 0;
 168     const char *ibuf = &c;
 169     char ch = UNKNCHAR;
 170
 171     int ibuflen = 1;
 172
 173     tmp_buff = g_convert_with_iconv (ibuf, ibuflen, cd, &bytes_read, &bytes_written, NULL);
 174     if ( tmp_buff )
 175         ch = tmp_buff[0];
 176     g_free (tmp_buff);
 177     return ch;
 178 }
 179
 180 char errbuf[255];
 181
 182 /*
 183  * FIXME: This assumes that ASCII is always the first encoding
 184  * in mc.charsets
 185  */
 186 #define CP_ASCII 0
 187
 188 const char *
 189 init_translation_table (int cpsource, int cpdisplay)
 190 {
 191     int i;
 192     GIConv cd;
 193
 194     /* Fill inpit <-> display tables */
 195
 196     if (cpsource < 0 || cpdisplay < 0 || cpsource == cpdisplay) {
 197         for (i = 0; i <= 255; ++i) {
 198             conv_displ[i] = i;
 199             conv_input[i] = i;
 200             cp_source = cp_display;
 201         }
 202         return NULL;
 203     }
 204
 205     for (i = 0; i <= 127; ++i) {
 206         conv_displ[i] = i;
 207         conv_input[i] = i;
 208     }
 209     cp_source = (char *) codepages[cpsource].id;
 210     cp_display = (char *) codepages[cpdisplay].id;
 211
 212     /* display <- inpit table */
 213
 214     cd = g_iconv_open (cp_display, cp_source);
 215     if (cd == INVALID_CONV) {
 216         g_snprintf (errbuf, sizeof (errbuf),
 217                     _("Cannot translate from %s to %s"), cp_source, cp_display);
 218         return errbuf;
 219     }
 220
 221     for (i = 128; i <= 255; ++i)
 222         conv_displ[i] = translate_character (cd, i);
 223
 224     g_iconv_close (cd);
 225
 226     /* inpit <- display table */
 227
 228     cd = g_iconv_open (cp_source, cp_display);
 229     if (cd == INVALID_CONV) {
 230         g_snprintf (errbuf, sizeof (errbuf),
 231                     _("Cannot translate from %s to %s"), cp_display, cp_source);
 232         return errbuf;
 233     }
 234
 235     for (i = 128; i <= 255; ++i) {
 236         unsigned char ch;
 237         ch = translate_character (cd, i);
 238         conv_input[i] = (ch == UNKNCHAR) ? i : ch;
 239     }
 240
 241     g_iconv_close (cd);
 242
 243     return NULL;
 244 }
 245
 246 void
 247 convert_to_display (char *str)
 248 {
 249     if (!str)
 250         return;
 251
 252     while (*str) {
 253         *str = conv_displ[(unsigned char) *str];
 254         str++;
 255     }
 256 }
 257
 258 GString *
 259 str_convert_to_display (char *str)
 260 {
 261     return str_nconvert_to_display (str, -1);
 262
 263 }
 264
 265 GString *
 266 str_nconvert_to_display (char *str, int len)
 267 {
 268     GString *buff;
 269     GIConv conv;
 270
 271     if (!str)
 272         return g_string_new("");
 273
 274     if (cp_display == cp_source)
 275         return g_string_new(str);
 276
 277     conv = str_crt_conv_from (cp_source);
 278
 279     buff = g_string_new("");
 280     str_nconvert (conv, str, len, buff);
 281     str_close_conv (conv);
 282     return buff;
 283 }
 284
 285 void
 286 convert_from_input (char *str)
 287 {
 288     if (!str)
 289         return;
 290
 291     while (*str) {
 292         *str = conv_input[(unsigned char) *str];
 293         str++;
 294     }
 295 }
 296
 297 GString *
 298 str_convert_to_input (char *str)
 299 {
 300     return str_nconvert_to_input (str, -1);
 301 }
 302
 303 GString *
 304 str_nconvert_to_input (char *str, int len)
 305 {
 306     GString *buff;
 307     GIConv conv;
 308
 309     if (!str)
 310         return g_string_new("");
 311
 312     if (cp_display == cp_source)
 313         return g_string_new(str);
 314
 315     conv = str_crt_conv_to (cp_source);
 316
 317     buff = g_string_new("");
 318     str_nconvert (conv, str, len, buff);
 319     str_close_conv (conv);
 320     return buff;
 321 }
 322
 323 unsigned char
 324 convert_from_utf_to_current (const char *str)
 325 {
 326     unsigned char buf_ch[6 + 1];
 327     unsigned char ch = '.';
 328     GIConv conv;
 329     const char *cp_to;
 330
 331     if (!str)
 332         return '.';
 333
 334     cp_to =  get_codepage_id ( source_codepage );
 335     conv = str_crt_conv_to ( cp_to );
 336
 337     if (conv != INVALID_CONV) {
 338         switch (str_translate_char (conv, str, -1, (char *)buf_ch, sizeof(buf_ch))) {
 339         case ESTR_SUCCESS:
 340             ch = buf_ch[0];
 341             break;
 342         case ESTR_PROBLEM:
 343         case ESTR_FAILURE:
 344             ch = '.';
 345             break;
 346         }
 347         str_close_conv (conv);
 348     }
 349
 350     return ch;
 351
 352 }
 353
 354 unsigned char
 355 convert_from_utf_to_current_c (const int input_char, GIConv conv)
 356 {
 357     unsigned char str[6 + 1];
 358     unsigned char buf_ch[6 + 1];
 359     unsigned char ch = '.';
 360
 361     int res = 0;
 362
 363     res = g_unichar_to_utf8 (input_char, (char *)str);
 364     if ( res == 0 ) {
 365         return ch;
 366     }
 367     str[res] = '\0';
 368
 369     switch (str_translate_char (conv, (char *)str, -1, (char *)buf_ch, sizeof(buf_ch))) {
 370     case ESTR_SUCCESS:
 371         ch = buf_ch[0];
 372         break;
 373     case ESTR_PROBLEM:
 374     case ESTR_FAILURE:
 375         ch = '.';
 376         break;
 377     }
 378     return ch;
 379 }
 380
 381 int
 382 convert_from_8bit_to_utf_c (const char input_char, GIConv conv)
 383 {
 384     unsigned char str[2];
 385     unsigned char buf_ch[6 + 1];
 386     int ch = '.';
 387     int res = 0;
 388
 389     str[0] = (unsigned char) input_char;
 390     str[1] = '\0';
 391
 392     switch (str_translate_char (conv, (char *)str, -1, (char *)buf_ch, sizeof(buf_ch))) {
 393     case ESTR_SUCCESS:
 394         res = g_utf8_get_char_validated ((char *)buf_ch, -1);
 395         if ( res < 0 ) {
 396             ch = buf_ch[0];
 397         } else {
 398             ch = res;
 399         }
 400         break;
 401     case ESTR_PROBLEM:
 402     case ESTR_FAILURE:
 403         ch = '.';
 404         break;
 405     }
 406     return ch;
 407 }
 408
 409 int
 410 convert_from_8bit_to_utf_c2 (const char input_char)
 411 {
 412     unsigned char str[2];
 413     unsigned char buf_ch[6 + 1];
 414     int ch = '.';
 415     int res = 0;
 416     GIConv conv;
 417     const char *cp_from;
 418
 419     str[0] = (unsigned char) input_char;
 420     str[1] = '\0';
 421
 422     cp_from = get_codepage_id ( source_codepage );
 423     conv = str_crt_conv_to (cp_from);
 424
 425     if (conv != INVALID_CONV) {
 426         switch (str_translate_char (conv, (char *) str, -1, (char *) buf_ch, sizeof(buf_ch))) {
 427         case ESTR_SUCCESS:
 428             res = g_utf8_get_char_validated ((char *) buf_ch, -1);
 429             if ( res < 0 ) {
 430                 ch = buf_ch[0];
 431             } else {
 432                 ch = res;
 433             }
 434             break;
 435         case ESTR_PROBLEM:
 436         case ESTR_FAILURE:
 437             ch = '.';
 438             break;
 439         }
 440         str_close_conv (conv);
 441     }
 442     return ch;
 443
 444 }
 445 #endif                          /* HAVE_CHARSET */