iconv/iconv_charmap.c

   1 /* Convert using charmaps and possibly iconv().
   2    Copyright (C) 2001 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <assert.h>
  22 #include <errno.h>
  23 #include <error.h>
  24 #include <fcntl.h>
  25 #include <iconv.h>
  26 #include <libintl.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <unistd.h>
  30 #include <sys/mman.h>
  31 #include <sys/stat.h>
  32
  33 #include "iconv_prog.h"
  34
  35
  36 /* Prototypes for a few program-wide used functions.  */
  37 extern void *xmalloc (size_t __n);
  38 extern void *xcalloc (size_t __n, size_t __s);
  39
  40
  41 struct convtable
  42 {
  43   int term[256 / 8];
  44   union
  45   {
  46     struct convtable *sub;
  47     struct charseq *out;
  48   } val[256];
  49 };
  50
  51
  52 static inline struct convtable *
  53 allocate_table (void)
  54 {
  55   return (struct convtable *) xcalloc (1, sizeof (struct convtable));
  56 }
  57
  58
  59 static inline int
  60 is_term (struct convtable *tbl, unsigned int idx)
  61 {
  62   return tbl->term[idx / 8] & (1 << (idx % 8));
  63 }
  64
  65
  66 static inline void
  67 clear_term (struct convtable *tbl, unsigned int idx)
  68 {
  69   tbl->term[idx / 8] &= ~(1 << (idx % 8));
  70 }
  71
  72
  73 static inline void
  74 set_term (struct convtable *tbl, unsigned int idx)
  75 {
  76   tbl->term[idx / 8] |= 1 << (idx % 8);
  77 }
  78
  79
  80 /* Generate the conversion table.  */
  81 static struct convtable *use_from_charmap (struct charmap_t *from_charmap,
  82                                            const char *to_code);
  83 static struct convtable *use_to_charmap (const char *from_code,
  84                                          struct charmap_t *to_charmap);
  85 static struct convtable *use_both_charmaps (struct charmap_t *from_charmap,
  86                                             struct charmap_t *to_charmap);
  87
  88 /* Prototypes for the functions doing the actual work.  */
  89 static int process_block (struct convtable *tbl, char *addr, size_t len,
  90                           FILE *output);
  91 static int process_fd (struct convtable *tbl, int fd, FILE *output);
  92 static int process_file (struct convtable *tbl, FILE *input, FILE *output);
  93
  94
  95 int
  96 charmap_conversion (const char *from_code, struct charmap_t *from_charmap,
  97                     const char *to_code, struct charmap_t *to_charmap,
  98                     int argc, int remaining, char *argv[], FILE *output)
  99 {
 100   struct convtable *cvtbl;
 101   int status = EXIT_SUCCESS;
 102
 103   /* We have three different cases to handle:
 104
 105      - both, from_charmap and to_charmap, are available.  This means we
 106        can assume that the symbolic names match and use them to create
 107        the mapping.
 108
 109      - only from_charmap is available.  In this case we can only hope that
 110        the symbolic names used are of the <Uxxxx> form in which case we
 111        can use a UCS4->"to_code" iconv() conversion for the second step.
 112
 113      - only to_charmap is available.  This is similar, only that we would
 114        use iconv() for the "to_code"->UCS4 conversion.
 115
 116        We first create a table which maps input bytes into output bytes.
 117        Once this is done we can handle all three of the cases above
 118        equally.  */
 119   if (from_charmap != NULL)
 120     {
 121       if (to_charmap == NULL)
 122         cvtbl = use_from_charmap (from_charmap, to_code);
 123       else
 124         cvtbl = use_both_charmaps (from_charmap, to_charmap);
 125     }
 126   else
 127     {
 128       assert (to_charmap != NULL);
 129       cvtbl = use_to_charmap (from_code, to_charmap);
 130     }
 131
 132   /* If we couldn't generate a table stop now.  */
 133   if (cvtbl == NULL)
 134     return EXIT_FAILURE;
 135
 136   /* We can now start the conversion.  */
 137   if (remaining == argc)
 138     {
 139       if (process_file (cvtbl, stdin, output) != 0)
 140         status = EXIT_FAILURE;
 141     }
 142   else
 143     do
 144       {
 145         struct stat st;
 146         char *addr;
 147         int fd;
 148
 149         if (verbose)
 150           printf ("%s:\n", argv[remaining]);
 151         if (strcmp (argv[remaining], "-") == 0)
 152           fd = 0;
 153         else
 154           {
 155             fd = open (argv[remaining], O_RDONLY);
 156
 157             if (fd == -1)
 158               {
 159                 error (0, errno, _("cannot open input file `%s'"),
 160                        argv[remaining]);
 161                 status = EXIT_FAILURE;
 162                 continue;
 163               }
 164           }
 165
 166 #ifdef _POSIX_MAPPED_FILES
 167         /* We have possibilities for reading the input file.  First try
 168            to mmap() it since this will provide the fastest solution.  */
 169         if (fstat (fd, &st) == 0
 170             && ((addr = mmap (NULL, st.st_size, PROT_READ, MAP_PRIVATE,
 171                               fd, 0)) != MAP_FAILED))
 172           {
 173             /* Yes, we can use mmap().  The descriptor is not needed
 174                anymore.  */
 175             if (close (fd) != 0)
 176               error (EXIT_FAILURE, errno,
 177                      _("error while closing input `%s'"), argv[remaining]);
 178
 179             if (process_block (cvtbl, addr, st.st_size, output) < 0)
 180               {
 181                 /* Something went wrong.  */
 182                 status = EXIT_FAILURE;
 183
 184                 /* We don't need the input data anymore.  */
 185                 munmap ((void *) addr, st.st_size);
 186
 187                 /* We cannot go on with producing output since it might
 188                    lead to problem because the last output might leave
 189                    the output stream in an undefined state.  */
 190                 break;
 191               }
 192
 193             /* We don't need the input data anymore.  */
 194             munmap ((void *) addr, st.st_size);
 195           }
 196         else
 197 #endif  /* _POSIX_MAPPED_FILES */
 198           {
 199             /* Read the file in pieces.  */
 200             if (process_fd (cvtbl, fd, output) != 0)
 201               {
 202                 /* Something went wrong.  */
 203                 status = EXIT_FAILURE;
 204
 205                 /* We don't need the input file anymore.  */
 206                 close (fd);
 207
 208                 /* We cannot go on with producing output since it might
 209                    lead to problem because the last output might leave
 210                    the output stream in an undefined state.  */
 211                 break;
 212               }
 213
 214             /* Now close the file.  */
 215             close (fd);
 216           }
 217       }
 218     while (++remaining < argc);
 219
 220   /* All done.  */
 221   return status;
 222 }
 223
 224
 225 static void
 226 add_bytes (struct convtable *tbl, struct charseq *in, struct charseq *out)
 227 {
 228   int n = 0;
 229   unsigned int byte;
 230
 231   assert (in->nbytes > 0);
 232
 233   byte = ((unsigned char *) in->bytes)[n];
 234   while (n + 1 < in->nbytes)
 235     {
 236       if (is_term (tbl, byte) || tbl->val[byte].sub == NULL)
 237         {
 238           /* Note that we simply ignore a definition for a byte sequence
 239              which is also the prefix for a longer one.  */
 240           clear_term (tbl, byte);
 241           tbl->val[byte].sub =
 242             (struct convtable *) xcalloc (1, sizeof (struct convtable));
 243         }
 244
 245       tbl = tbl->val[byte].sub;
 246
 247       byte = ((unsigned char *) in->bytes)[++n];
 248     }
 249
 250   /* Only add the new sequence if there is none yet and the byte sequence
 251      is not part of an even longer one.  */
 252   if (! is_term (tbl, byte) && tbl->val[byte].sub == NULL)
 253     {
 254       set_term (tbl, byte);
 255       tbl->val[byte].out = out;
 256     }
 257 }
 258
 259
 260 static struct convtable *
 261 use_from_charmap (struct charmap_t *from_charmap, const char *to_code)
 262 {
 263   /* We iterate over all entries in the from_charmap and for those which
 264      have a known UCS4 representation we use an iconv() call to determine
 265      the mapping to the to_code charset.  */
 266   struct convtable *rettbl;
 267   iconv_t cd;
 268   void *ptr = NULL;
 269   const void *key;
 270   size_t keylen;
 271   void *data;
 272
 273   cd = iconv_open (to_code, "WCHAR_T");
 274   if (cd == (iconv_t) -1)
 275     /* We cannot do anything.  */
 276     return NULL;
 277
 278   rettbl = allocate_table ();
 279
 280   while (iterate_table (&from_charmap->char_table, &ptr, &key, &keylen, &data)
 281          >= 0)
 282     {
 283       struct charseq *in = (struct charseq *) data;
 284
 285       if (in->ucs4 != UNINITIALIZED_CHAR_VALUE)
 286         {
 287           /* There is a chance.  Try the iconv module.  */
 288           wchar_t inbuf[1] = { in->ucs4 };
 289           unsigned char outbuf[64];
 290           char *inptr = (char *) inbuf;
 291           size_t inlen = sizeof (inbuf);
 292           char *outptr = (char *) outbuf;
 293           size_t outlen = sizeof (outbuf);
 294
 295           (void) iconv (cd, &inptr, &inlen, &outptr, &outlen);
 296
 297           if (outptr != (char *) outbuf)
 298             {
 299               /* We got some output.  Good, use it.  */
 300               struct charseq *newp;
 301
 302               outlen = sizeof (outbuf) - outlen;
 303               assert ((char *) outbuf + outlen == outptr);
 304
 305               newp = (struct charseq *) xmalloc (sizeof (struct charseq)
 306                                                  + outlen);
 307               newp->name = in->name;
 308               newp->ucs4 = in->ucs4;
 309               newp->nbytes = outlen;
 310               memcpy (newp->bytes, outbuf, outlen);
 311
 312               add_bytes (rettbl, in, newp);
 313             }
 314
 315           /* Clear any possible state left behind.  */
 316           (void) iconv (cd, NULL, NULL, NULL, NULL);
 317         }
 318     }
 319
 320   iconv_close (cd);
 321
 322   return rettbl;
 323 }
 324
 325
 326 static struct convtable *
 327 use_to_charmap (const char *from_code, struct charmap_t *to_charmap)
 328 {
 329   /* We iterate over all entries in the to_charmap and for those which
 330      have a known UCS4 representation we use an iconv() call to determine
 331      the mapping to the from_code charset.  */
 332   struct convtable *rettbl;
 333   iconv_t cd;
 334   void *ptr = NULL;
 335   const void *key;
 336   size_t keylen;
 337   void *data;
 338
 339   /* Note that the conversion we use here is the reverse direction.  Without
 340      exhaustive search we cannot figure out which input yields the UCS4
 341      character we are looking for.  Therefore we determine it the other
 342      way round.  */
 343   cd = iconv_open (from_code, "WCHAR_T");
 344   if (cd == (iconv_t) -1)
 345     /* We cannot do anything.  */
 346     return NULL;
 347
 348   rettbl = allocate_table ();
 349
 350   while (iterate_table (&to_charmap->char_table, &ptr, &key, &keylen, &data)
 351          >= 0)
 352     {
 353       struct charseq *out = (struct charseq *) data;
 354
 355       if (out->ucs4 != UNINITIALIZED_CHAR_VALUE)
 356         {
 357           /* There is a chance.  Try the iconv module.  */
 358           wchar_t inbuf[1] = { out->ucs4 };
 359           unsigned char outbuf[64];
 360           char *inptr = (char *) inbuf;
 361           size_t inlen = sizeof (inbuf);
 362           char *outptr = (char *) outbuf;
 363           size_t outlen = sizeof (outbuf);
 364
 365           (void) iconv (cd, &inptr, &inlen, &outptr, &outlen);
 366
 367           if (outptr != (char *) outbuf)
 368             {
 369               /* We got some output.  Good, use it.  */
 370               struct charseq *newp;
 371
 372               outlen = sizeof (outbuf) - outlen;
 373               assert ((char *) outbuf + outlen == outptr);
 374
 375               newp = (struct charseq *) xmalloc (sizeof (struct charseq)
 376                                                  + outlen);
 377               newp->name = out->name;
 378               newp->ucs4 = out->ucs4;
 379               newp->nbytes = outlen;
 380               memcpy (newp->bytes, outbuf, outlen);
 381
 382               add_bytes (rettbl, newp, out);
 383             }
 384
 385           /* Clear any possible state left behind.  */
 386           (void) iconv (cd, NULL, NULL, NULL, NULL);
 387         }
 388     }
 389
 390   iconv_close (cd);
 391
 392   return rettbl;
 393 }
 394
 395
 396 static struct convtable *
 397 use_both_charmaps (struct charmap_t *from_charmap,
 398                    struct charmap_t *to_charmap)
 399 {
 400   /* In this case we iterate over all the entries in the from_charmap,
 401      determine the internal name, and find an appropriate entry in the
 402      to_charmap (if it exists).  */
 403   struct convtable *rettbl = allocate_table ();
 404   void *ptr = NULL;
 405   const void *key;
 406   size_t keylen;
 407   void *data;
 408
 409   while (iterate_table (&from_charmap->char_table, &ptr, &key, &keylen, &data)
 410          >= 0)
 411     {
 412       struct charseq *in = (struct charseq *) data;
 413       struct charseq *out = charmap_find_value (to_charmap, key, keylen);
 414
 415       if (out != NULL)
 416         add_bytes (rettbl, in, out);
 417     }
 418
 419   return rettbl;
 420 }
 421
 422
 423 static int
 424 process_block (struct convtable *tbl, char *addr, size_t len, FILE *output)
 425 {
 426   size_t n = 0;
 427
 428   while (n < len)
 429     {
 430       struct convtable *cur = tbl;
 431       unsigned char *curp = (unsigned char *) addr;
 432       unsigned int byte = *curp;
 433       int cnt;
 434       struct charseq *out;
 435
 436       while (! is_term (cur, byte))
 437         if (cur->val[byte].sub == NULL)
 438           {
 439             /* This is a invalid sequence.  Skip the first byte if we are
 440                ignoring errors.  Otherwise punt.  */
 441             if (! omit_invalid)
 442               {
 443                 error (0, 0, _("illegal input sequence at position %Zd"), n);
 444                 return -1;
 445               }
 446
 447             n -= curp - (unsigned char *) addr;
 448
 449             byte = *(curp = (unsigned char *) ++addr);
 450             if (++n >= len)
 451               /* All converted.  */
 452               return 0;
 453
 454             cur = tbl;
 455           }
 456         else
 457           {
 458             cur = cur->val[byte].sub;
 459
 460             if (++n >= len)
 461               {
 462                 error (0, 0, _("\
 463 incomplete character or shift sequence at end of buffer"));
 464                 return -1;
 465               }
 466
 467             byte = *++curp;
 468           }
 469
 470       /* We found a final byte.  Write the output bytes.  */
 471       out = cur->val[byte].out;
 472       for (cnt = 0; cnt < out->nbytes; ++cnt)
 473         fputc_unlocked (out->bytes[cnt], output);
 474
 475       addr = (char *) curp + 1;
 476       ++n;
 477     }
 478
 479   return 0;
 480 }
 481
 482
 483 static int
 484 process_fd (struct convtable *tbl, int fd, FILE *output)
 485 {
 486   /* we have a problem with reading from a desriptor since we must not
 487      provide the iconv() function an incomplete character or shift
 488      sequence at the end of the buffer.  Since we have to deal with
 489      arbitrary encodings we must read the whole text in a buffer and
 490      process it in one step.  */
 491   static char *inbuf = NULL;
 492   static size_t maxlen = 0;
 493   char *inptr = NULL;
 494   size_t actlen = 0;
 495
 496   while (actlen < maxlen)
 497     {
 498       ssize_t n = read (fd, inptr, maxlen - actlen);
 499
 500       if (n == 0)
 501         /* No more text to read.  */
 502         break;
 503
 504       if (n == -1)
 505         {
 506           /* Error while reading.  */
 507           error (0, errno, _("error while reading the input"));
 508           return -1;
 509         }
 510
 511       inptr += n;
 512       actlen += n;
 513     }
 514
 515   if (actlen == maxlen)
 516     while (1)
 517       {
 518         ssize_t n;
 519
 520         /* Increase the buffer.  */
 521         maxlen += 32768;
 522         inbuf = realloc (inbuf, maxlen);
 523         if (inbuf == NULL)
 524           error (0, errno, _("unable to allocate buffer for input"));
 525         inptr = inbuf + actlen;
 526
 527         do
 528           {
 529             n = read (fd, inptr, maxlen - actlen);
 530
 531             if (n == 0)
 532               /* No more text to read.  */
 533               break;
 534
 535             if (n == -1)
 536               {
 537                 /* Error while reading.  */
 538                 error (0, errno, _("error while reading the input"));
 539                 return -1;
 540               }
 541
 542             inptr += n;
 543             actlen += n;
 544           }
 545         while (actlen < maxlen);
 546
 547         if (n == 0)
 548           /* Break again so we leave both loops.  */
 549           break;
 550       }
 551
 552   /* Now we have all the input in the buffer.  Process it in one run.  */
 553   return process_block (tbl, inbuf, actlen, output);
 554 }
 555
 556
 557 static int
 558 process_file (struct convtable *tbl, FILE *input, FILE *output)
 559 {
 560   /* This should be safe since we use this function only for `stdin' and
 561      we haven't read anything so far.  */
 562   return process_fd (tbl, fileno (input), output);
 563 }