iconv/iconv_prog.c

   1 /* Convert text in given files from the specified from-set to the to-set.
   2    Copyright (C) 1998-2008, 2009 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published
   8    by the Free Software Foundation; version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program 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
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 #include <argp.h>
  21 #include <assert.h>
  22 #include <ctype.h>
  23 #include <errno.h>
  24 #include <error.h>
  25 #include <fcntl.h>
  26 #include <iconv.h>
  27 #include <langinfo.h>
  28 #include <locale.h>
  29 #include <search.h>
  30 #include <stdbool.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <unistd.h>
  35 #include <libintl.h>
  36 #ifdef _POSIX_MAPPED_FILES
  37 # include <sys/mman.h>
  38 #endif
  39 #include <charmap.h>
  40 #include <gconv_int.h>
  41 #include "iconv_prog.h"
  42 #include "iconvconfig.h"
  43
  44 /* Get libc version number.  */
  45 #include "../version.h"
  46
  47 #define PACKAGE _libc_intl_domainname
  48
  49
  50 /* Name and version of program.  */
  51 static void print_version (FILE *stream, struct argp_state *state);
  52 void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
  53
  54 #define OPT_VERBOSE     1000
  55 #define OPT_LIST        'l'
  56
  57 /* Definitions of arguments for argp functions.  */
  58 static const struct argp_option options[] =
  59 {
  60   { NULL, 0, NULL, 0, N_("Input/Output format specification:") },
  61   { "from-code", 'f', "NAME", 0, N_("encoding of original text") },
  62   { "to-code", 't', "NAME", 0, N_("encoding for output") },
  63   { NULL, 0, NULL, 0, N_("Information:") },
  64   { "list", 'l', NULL, 0, N_("list all known coded character sets") },
  65   { NULL, 0, NULL, 0, N_("Output control:") },
  66   { NULL, 'c', NULL, 0, N_("omit invalid characters from output") },
  67   { "output", 'o', "FILE", 0, N_("output file") },
  68   { "silent", 's', NULL, 0, N_("suppress warnings") },
  69   { "verbose", OPT_VERBOSE, NULL, 0, N_("print progress information") },
  70   { NULL, 0, NULL, 0, NULL }
  71 };
  72
  73 /* Short description of program.  */
  74 static const char doc[] = N_("\
  75 Convert encoding of given files from one encoding to another.");
  76
  77 /* Strings for arguments in help texts.  */
  78 static const char args_doc[] = N_("[FILE...]");
  79
  80 /* Prototype for option handler.  */
  81 static error_t parse_opt (int key, char *arg, struct argp_state *state);
  82
  83 /* Function to print some extra text in the help message.  */
  84 static char *more_help (int key, const char *text, void *input);
  85
  86 /* Data structure to communicate with argp functions.  */
  87 static struct argp argp =
  88 {
  89   options, parse_opt, args_doc, doc, NULL, more_help
  90 };
  91
  92 /* Code sets to convert from and to respectively.  An empty string as the
  93    default causes the 'iconv_open' function to look up the charset of the
  94    currently selected locale and use it.  */
  95 static const char *from_code = "";
  96 static const char *to_code = "";
  97
  98 /* File to write output to.  If NULL write to stdout.  */
  99 static const char *output_file;
 100
 101 /* Nonzero if verbose ouput is wanted.  */
 102 int verbose;
 103
 104 /* Nonzero if list of all coded character sets is wanted.  */
 105 static int list;
 106
 107 /* If nonzero omit invalid character from output.  */
 108 int omit_invalid;
 109
 110 /* Prototypes for the functions doing the actual work.  */
 111 static int process_block (iconv_t cd, char *addr, size_t len, FILE **output,
 112                           const char *output_file);
 113 static int process_fd (iconv_t cd, int fd, FILE **output,
 114                        const char *output_file);
 115 static int process_file (iconv_t cd, FILE *input, FILE **output,
 116                          const char *output_file);
 117 static void print_known_names (void) internal_function;
 118
 119
 120 int
 121 main (int argc, char *argv[])
 122 {
 123   int status = EXIT_SUCCESS;
 124   int remaining;
 125   iconv_t cd;
 126   const char *orig_to_code;
 127   struct charmap_t *from_charmap = NULL;
 128   struct charmap_t *to_charmap = NULL;
 129
 130   /* Set locale via LC_ALL.  */
 131   setlocale (LC_ALL, "");
 132
 133   /* Set the text message domain.  */
 134   textdomain (_libc_intl_domainname);
 135
 136   /* Parse and process arguments.  */
 137   argp_parse (&argp, argc, argv, 0, &remaining, NULL);
 138
 139   /* List all coded character sets if wanted.  */
 140   if (list)
 141     {
 142       print_known_names ();
 143       exit (EXIT_SUCCESS);
 144     }
 145
 146   /* If we have to ignore errors make sure we use the appropriate name for
 147      the to-character-set.  */
 148   orig_to_code = to_code;
 149   if (omit_invalid)
 150     {
 151       const char *errhand = strchrnul (to_code, '/');
 152       int nslash = 2;
 153       char *newp;
 154       char *cp;
 155
 156       if (*errhand == '/')
 157         {
 158           --nslash;
 159           errhand = strchrnul (errhand, '/');
 160
 161           if (*errhand == '/')
 162             {
 163               --nslash;
 164               errhand = strchr (errhand, '\0');
 165             }
 166         }
 167
 168       newp = (char *) alloca (errhand - to_code + nslash + 7 + 1);
 169       cp = mempcpy (newp, to_code, errhand - to_code);
 170       while (nslash-- > 0)
 171         *cp++ = '/';
 172       if (cp[-1] != '/')
 173         *cp++ = ',';
 174       memcpy (cp, "IGNORE", sizeof ("IGNORE"));
 175
 176       to_code = newp;
 177     }
 178
 179   /* POSIX 1003.2b introduces a silly thing: the arguments to -t anf -f
 180      can be file names of charmaps.  In this case iconv will have to read
 181      those charmaps and use them to do the conversion.  But there are
 182      holes in the specification.  There is nothing said that if -f is a
 183      charmap filename that -t must be, too.  And vice versa.  There is
 184      also no word about the symbolic names used.  What if they don't
 185      match?  */
 186   if (strchr (from_code, '/') != NULL)
 187     /* The from-name might be a charmap file name.  Try reading the
 188        file.  */
 189     from_charmap = charmap_read (from_code, /*0, 1*/1, 0, 0, 0);
 190
 191   if (strchr (orig_to_code, '/') != NULL)
 192     /* The to-name might be a charmap file name.  Try reading the
 193        file.  */
 194     to_charmap = charmap_read (orig_to_code, /*0, 1,*/1, 0, 0, 0);
 195
 196
 197   /* At this point we have to handle two cases.  The first one is
 198      where a charmap is used for the from- or to-charset, or both.  We
 199      handle this special since it is very different from the sane way of
 200      doing things.  The other case allows converting using the iconv()
 201      function.  */
 202   if (from_charmap != NULL || to_charmap != NULL)
 203     /* Construct the conversion table and do the conversion.  */
 204     status = charmap_conversion (from_code, from_charmap, to_code, to_charmap,
 205                                  argc, remaining, argv, output_file);
 206   else
 207     {
 208       /* Let's see whether we have these coded character sets.  */
 209       cd = iconv_open (to_code, from_code);
 210       if (cd == (iconv_t) -1)
 211         {
 212           if (errno == EINVAL)
 213             {
 214               /* Try to be nice with the user and tell her which of the
 215                  two encoding names is wrong.  This is possible because
 216                  all supported encodings can be converted from/to Unicode,
 217                  in other words, because the graph of encodings is
 218                  connected.  */
 219               bool from_wrong =
 220                 (iconv_open ("UTF-8", from_code) == (iconv_t) -1
 221                  && errno == EINVAL);
 222               bool to_wrong =
 223                 (iconv_open (to_code, "UTF-8") == (iconv_t) -1
 224                  && errno == EINVAL);
 225               const char *from_pretty =
 226                 (from_code[0] ? from_code : nl_langinfo (CODESET));
 227               const char *to_pretty =
 228                 (orig_to_code[0] ? orig_to_code : nl_langinfo (CODESET));
 229
 230               if (from_wrong)
 231                 {
 232                   if (to_wrong)
 233                     error (0, 0,
 234                            _("\
 235 conversions from `%s' and to `%s' are not supported"),
 236                            from_pretty, to_pretty);
 237                   else
 238                     error (0, 0,
 239                            _("conversion from `%s' is not supported"),
 240                            from_pretty);
 241                 }
 242               else
 243                 {
 244                   if (to_wrong)
 245                     error (0, 0,
 246                            _("conversion to `%s' is not supported"),
 247                            to_pretty);
 248                   else
 249                     error (0, 0,
 250                            _("conversion from `%s' to `%s' is not supported"),
 251                            from_pretty, to_pretty);
 252                 }
 253
 254               argp_help (&argp, stderr, ARGP_HELP_SEE,
 255                          program_invocation_short_name);
 256               exit (1);
 257             }
 258           else
 259             error (EXIT_FAILURE, errno,
 260                    _("failed to start conversion processing"));
 261         }
 262
 263       /* The output file.  Will be opened when we are ready to produce
 264          output.  */
 265       FILE *output = NULL;
 266
 267       /* Now process the remaining files.  Write them to stdout or the file
 268          specified with the `-o' parameter.  If we have no file given as
 269          the parameter process all from stdin.  */
 270       if (remaining == argc)
 271         {
 272           if (process_file (cd, stdin, &output, output_file) != 0)
 273             status = EXIT_FAILURE;
 274         }
 275       else
 276         do
 277           {
 278 #ifdef _POSIX_MAPPED_FILES
 279             struct stat st;
 280             char *addr;
 281 #endif
 282             int fd, ret;
 283
 284             if (verbose)
 285               fprintf (stderr, "%s:\n", argv[remaining]);
 286             if (strcmp (argv[remaining], "-") == 0)
 287               fd = 0;
 288             else
 289               {
 290                 fd = open (argv[remaining], O_RDONLY);
 291
 292                 if (fd == -1)
 293                   {
 294                     error (0, errno, _("cannot open input file `%s'"),
 295                            argv[remaining]);
 296                     status = EXIT_FAILURE;
 297                     continue;
 298                   }
 299               }
 300
 301 #ifdef _POSIX_MAPPED_FILES
 302             /* We have possibilities for reading the input file.  First try
 303                to mmap() it since this will provide the fastest solution.  */
 304             if (fstat (fd, &st) == 0
 305                 && ((addr = mmap (NULL, st.st_size, PROT_READ, MAP_PRIVATE,
 306                                   fd, 0)) != MAP_FAILED))
 307               {
 308                 /* Yes, we can use mmap().  The descriptor is not needed
 309                    anymore.  */
 310                 if (close (fd) != 0)
 311                   error (EXIT_FAILURE, errno,
 312                          _("error while closing input `%s'"),
 313                          argv[remaining]);
 314
 315                 ret = process_block (cd, addr, st.st_size, &output,
 316                                      output_file);
 317
 318                 /* We don't need the input data anymore.  */
 319                 munmap ((void *) addr, st.st_size);
 320
 321                 if (ret != 0)
 322                   {
 323                     status = EXIT_FAILURE;
 324
 325                     if (ret < 0)
 326                       /* We cannot go on with producing output since it might
 327                          lead to problem because the last output might leave
 328                          the output stream in an undefined state.  */
 329                       break;
 330                   }
 331               }
 332             else
 333 #endif  /* _POSIX_MAPPED_FILES */
 334               {
 335                 /* Read the file in pieces.  */
 336                 ret = process_fd (cd, fd, &output, output_file);
 337
 338                 /* Now close the file.  */
 339                 close (fd);
 340
 341                 if (ret != 0)
 342                   {
 343                     /* Something went wrong.  */
 344                     status = EXIT_FAILURE;
 345
 346                     if (ret < 0)
 347                       /* We cannot go on with producing output since it might
 348                          lead to problem because the last output might leave
 349                          the output stream in an undefined state.  */
 350                       break;
 351                   }
 352               }
 353           }
 354         while (++remaining < argc);
 355
 356       /* Close the output file now.  */
 357       if (output != NULL && fclose (output))
 358         error (EXIT_FAILURE, errno, _("error while closing output file"));
 359     }
 360
 361   return status;
 362 }
 363
 364
 365 /* Handle program arguments.  */
 366 static error_t
 367 parse_opt (int key, char *arg, struct argp_state *state)
 368 {
 369   switch (key)
 370     {
 371     case 'f':
 372       from_code = arg;
 373       break;
 374     case 't':
 375       to_code = arg;
 376       break;
 377     case 'o':
 378       output_file = arg;
 379       break;
 380     case 's':
 381       /* Nothing, for now at least.  We are not giving out any information
 382          about missing character or so.  */
 383       break;
 384     case 'c':
 385       /* Omit invalid characters from output.  */
 386       omit_invalid = 1;
 387       break;
 388     case OPT_VERBOSE:
 389       verbose = 1;
 390       break;
 391     case OPT_LIST:
 392       list = 1;
 393       break;
 394     default:
 395       return ARGP_ERR_UNKNOWN;
 396     }
 397   return 0;
 398 }
 399
 400
 401 static char *
 402 more_help (int key, const char *text, void *input)
 403 {
 404   switch (key)
 405     {
 406     case ARGP_KEY_HELP_EXTRA:
 407       /* We print some extra information.  */
 408       return strdup (gettext ("\
 409 For bug reporting instructions, please see:\n\
 410 <http://www.gnu.org/software/libc/bugs.html>.\n"));
 411     default:
 412       break;
 413     }
 414   return (char *) text;
 415 }
 416
 417
 418 /* Print the version information.  */
 419 static void
 420 print_version (FILE *stream, struct argp_state *state)
 421 {
 422   fprintf (stream, "iconv (GNU %s) %s\n", PACKAGE, VERSION);
 423   fprintf (stream, gettext ("\
 424 Copyright (C) %s Free Software Foundation, Inc.\n\
 425 This is free software; see the source for copying conditions.  There is NO\n\
 426 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
 427 "), "2009");
 428   fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
 429 }
 430
 431
 432 static int
 433 write_output (const char *outbuf, const char *outptr, FILE **output,
 434               const char *output_file)
 435 {
 436   /* We have something to write out.  */
 437   int errno_save = errno;
 438
 439   if (*output == NULL)
 440     {
 441       /* Determine output file.  */
 442       if (output_file != NULL && strcmp (output_file, "-") != 0)
 443         {
 444           *output = fopen (output_file, "w");
 445           if (output == NULL)
 446             error (EXIT_FAILURE, errno, _("cannot open output file"));
 447         }
 448       else
 449         *output = stdout;
 450     }
 451
 452   if (fwrite (outbuf, 1, outptr - outbuf, *output) < (size_t) (outptr - outbuf)
 453       || ferror (*output))
 454     {
 455       /* Error occurred while printing the result.  */
 456       error (0, 0, _("\
 457 conversion stopped due to problem in writing the output"));
 458       return -1;
 459     }
 460
 461   errno = errno_save;
 462
 463   return 0;
 464 }
 465
 466
 467 static int
 468 process_block (iconv_t cd, char *addr, size_t len, FILE **output,
 469                const char *output_file)
 470 {
 471 #define OUTBUF_SIZE     32768
 472   const char *start = addr;
 473   char outbuf[OUTBUF_SIZE];
 474   char *outptr;
 475   size_t outlen;
 476   size_t n;
 477   int ret = 0;
 478
 479   while (len > 0)
 480     {
 481       outptr = outbuf;
 482       outlen = OUTBUF_SIZE;
 483       n = iconv (cd, &addr, &len, &outptr, &outlen);
 484
 485       if (n == (size_t) -1 && omit_invalid && errno == EILSEQ)
 486         {
 487           ret = 1;
 488           if (len == 0)
 489             n = 0;
 490           else
 491             errno = E2BIG;
 492         }
 493
 494       if (outptr != outbuf)
 495         {
 496           ret = write_output (outbuf, outptr, output, output_file);
 497           if (ret != 0)
 498             break;
 499         }
 500
 501       if (n != (size_t) -1)
 502         {
 503           /* All the input test is processed.  For state-dependent
 504              character sets we have to flush the state now.  */
 505           outptr = outbuf;
 506           outlen = OUTBUF_SIZE;
 507           n = iconv (cd, NULL, NULL, &outptr, &outlen);
 508
 509           if (outptr != outbuf)
 510             {
 511               ret = write_output (outbuf, outptr, output, output_file);
 512               if (ret != 0)
 513                 break;
 514             }
 515
 516           if (n != (size_t) -1)
 517             break;
 518
 519           if (omit_invalid && errno == EILSEQ)
 520             {
 521               ret = 1;
 522               break;
 523             }
 524         }
 525
 526       if (errno != E2BIG)
 527         {
 528           /* iconv() ran into a problem.  */
 529           switch (errno)
 530             {
 531             case EILSEQ:
 532               if (! omit_invalid)
 533                 error (0, 0, _("illegal input sequence at position %ld"),
 534                        (long int) (addr - start));
 535               break;
 536             case EINVAL:
 537               error (0, 0, _("\
 538 incomplete character or shift sequence at end of buffer"));
 539               break;
 540             case EBADF:
 541               error (0, 0, _("internal error (illegal descriptor)"));
 542               break;
 543             default:
 544               error (0, 0, _("unknown iconv() error %d"), errno);
 545               break;
 546             }
 547
 548           return -1;
 549         }
 550     }
 551
 552   return ret;
 553 }
 554
 555
 556 static int
 557 process_fd (iconv_t cd, int fd, FILE **output, const char *output_file)
 558 {
 559   /* we have a problem with reading from a desriptor since we must not
 560      provide the iconv() function an incomplete character or shift
 561      sequence at the end of the buffer.  Since we have to deal with
 562      arbitrary encodings we must read the whole text in a buffer and
 563      process it in one step.  */
 564   static char *inbuf = NULL;
 565   static size_t maxlen = 0;
 566   char *inptr = NULL;
 567   size_t actlen = 0;
 568
 569   while (actlen < maxlen)
 570     {
 571       ssize_t n = read (fd, inptr, maxlen - actlen);
 572
 573       if (n == 0)
 574         /* No more text to read.  */
 575         break;
 576
 577       if (n == -1)
 578         {
 579           /* Error while reading.  */
 580           error (0, errno, _("error while reading the input"));
 581           return -1;
 582         }
 583
 584       inptr += n;
 585       actlen += n;
 586     }
 587
 588   if (actlen == maxlen)
 589     while (1)
 590       {
 591         ssize_t n;
 592         char *new_inbuf;
 593
 594         /* Increase the buffer.  */
 595         new_inbuf = (char *) realloc (inbuf, maxlen + 32768);
 596         if (new_inbuf == NULL)
 597           {
 598             error (0, errno, _("unable to allocate buffer for input"));
 599             return -1;
 600           }
 601         inbuf = new_inbuf;
 602         maxlen += 32768;
 603         inptr = inbuf + actlen;
 604
 605         do
 606           {
 607             n = read (fd, inptr, maxlen - actlen);
 608
 609             if (n == 0)
 610               /* No more text to read.  */
 611               break;
 612
 613             if (n == -1)
 614               {
 615                 /* Error while reading.  */
 616                 error (0, errno, _("error while reading the input"));
 617                 return -1;
 618               }
 619
 620             inptr += n;
 621             actlen += n;
 622           }
 623         while (actlen < maxlen);
 624
 625         if (n == 0)
 626           /* Break again so we leave both loops.  */
 627           break;
 628       }
 629
 630   /* Now we have all the input in the buffer.  Process it in one run.  */
 631   return process_block (cd, inbuf, actlen, output, output_file);
 632 }
 633
 634
 635 static int
 636 process_file (iconv_t cd, FILE *input, FILE **output, const char *output_file)
 637 {
 638   /* This should be safe since we use this function only for `stdin' and
 639      we haven't read anything so far.  */
 640   return process_fd (cd, fileno (input), output, output_file);
 641 }
 642
 643
 644 /* Print all known character sets/encodings.  */
 645 static void *printlist;
 646 static size_t column;
 647 static int not_first;
 648
 649 static void
 650 insert_print_list (const void *nodep, VISIT value, int level)
 651 {
 652   if (value == leaf || value == postorder)
 653     {
 654       const struct gconv_alias *s = *(const struct gconv_alias **) nodep;
 655       tsearch (s->fromname, &printlist, (__compar_fn_t) strverscmp);
 656     }
 657 }
 658
 659 static void
 660 do_print_human  (const void *nodep, VISIT value, int level)
 661 {
 662   if (value == leaf || value == postorder)
 663     {
 664       const char *s = *(const char **) nodep;
 665       size_t len = strlen (s);
 666       size_t cnt;
 667
 668       while (len > 0 && s[len - 1] == '/')
 669         --len;
 670
 671       for (cnt = 0; cnt < len; ++cnt)
 672         if (isalnum (s[cnt]))
 673           break;
 674       if (cnt == len)
 675         return;
 676
 677       if (not_first)
 678         {
 679           putchar (',');
 680           ++column;
 681
 682           if (column > 2 && column + len > 77)
 683             {
 684               fputs ("\n  ", stdout);
 685               column = 2;
 686             }
 687           else
 688             {
 689               putchar (' ');
 690               ++column;
 691             }
 692         }
 693       else
 694         not_first = 1;
 695
 696       fwrite (s, len, 1, stdout);
 697       column += len;
 698     }
 699 }
 700
 701 static void
 702 do_print  (const void *nodep, VISIT value, int level)
 703 {
 704   if (value == leaf || value == postorder)
 705     {
 706       const char *s = *(const char **) nodep;
 707
 708       puts (s);
 709     }
 710 }
 711
 712 static void
 713 internal_function
 714 add_known_names (struct gconv_module *node)
 715 {
 716   if (node->left != NULL)
 717     add_known_names (node->left);
 718   if (node->right != NULL)
 719     add_known_names (node->right);
 720   do
 721     {
 722       if (strcmp (node->from_string, "INTERNAL"))
 723         tsearch (node->from_string, &printlist,
 724                  (__compar_fn_t) strverscmp);
 725       if (strcmp (node->to_string, "INTERNAL") != 0)
 726         tsearch (node->to_string, &printlist, (__compar_fn_t) strverscmp);
 727
 728       node = node->same;
 729     }
 730   while (node != NULL);
 731 }
 732
 733
 734 static void
 735 insert_cache (void)
 736 {
 737   const struct gconvcache_header *header;
 738   const char *strtab;
 739   const struct hash_entry *hashtab;
 740   size_t cnt;
 741
 742   header = (const struct gconvcache_header *) __gconv_get_cache ();
 743   strtab = (char *) header + header->string_offset;
 744   hashtab = (struct hash_entry *) ((char *) header + header->hash_offset);
 745
 746   for (cnt = 0; cnt < header->hash_size; ++cnt)
 747     if (hashtab[cnt].string_offset != 0)
 748       {
 749         const char *str = strtab + hashtab[cnt].string_offset;
 750
 751         if (strcmp (str, "INTERNAL") != 0)
 752           tsearch (str, &printlist, (__compar_fn_t) strverscmp);
 753       }
 754 }
 755
 756
 757 static void
 758 internal_function
 759 print_known_names (void)
 760 {
 761   iconv_t h;
 762   void *cache;
 763
 764   /* We must initialize the internal databases first.  */
 765   h = iconv_open ("L1", "L1");
 766   iconv_close (h);
 767
 768   /* See whether we have a cache.  */
 769   cache = __gconv_get_cache ();
 770   if (cache != NULL)
 771     /* Yep, use only this information.  */
 772     insert_cache ();
 773   else
 774     {
 775       struct gconv_module *modules;
 776
 777       /* No, then use the information read from the gconv-modules file.
 778          First add the aliases.  */
 779       twalk (__gconv_get_alias_db (), insert_print_list);
 780
 781       /* Add the from- and to-names from the known modules.  */
 782       modules = __gconv_get_modules_db ();
 783       if (modules != NULL)
 784         add_known_names (modules);
 785     }
 786
 787   bool human_readable = isatty (fileno (stdout));
 788
 789   if (human_readable)
 790     fputs (_("\
 791 The following list contain all the coded character sets known.  This does\n\
 792 not necessarily mean that all combinations of these names can be used for\n\
 793 the FROM and TO command line parameters.  One coded character set can be\n\
 794 listed with several different names (aliases).\n\n  "), stdout);
 795
 796   /* Now print the collected names.  */
 797   column = 2;
 798   twalk (printlist, human_readable ? do_print_human : do_print);
 799
 800   if (human_readable && column != 0)
 801     puts ("");
 802 }