lib/localcharset.c

   1 /* Determine a canonical name for the current locale's character encoding.
   2
   3    Copyright (C) 2000-2006, 2008-2024 Free Software Foundation, Inc.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file 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 Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Written by Bruno Haible <bruno@clisp.org>.  */
  19
  20 #include <config.h>
  21
  22 /* Specification.  */
  23 #include "localcharset.h"
  24
  25 #include <stddef.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29
  30 #if defined __APPLE__ && defined __MACH__ && HAVE_LANGINFO_CODESET
  31 # define DARWIN7 /* Darwin 7 or newer, i.e. Mac OS X 10.3 or newer */
  32 #endif
  33
  34 #if defined _WIN32 && !defined __CYGWIN__
  35 # define WINDOWS_NATIVE
  36 # include <locale.h>
  37 #endif
  38
  39 #if defined __EMX__
  40 /* Assume EMX program runs on OS/2, even if compiled under DOS.  */
  41 # ifndef OS2
  42 #  define OS2
  43 # endif
  44 #endif
  45
  46 #if !defined WINDOWS_NATIVE
  47 # if HAVE_LANGINFO_CODESET
  48 #  include <langinfo.h>
  49 # else
  50 #  if 0 /* see comment regarding use of setlocale(), below */
  51 #   include <locale.h>
  52 #  endif
  53 # endif
  54 # ifdef __CYGWIN__
  55 #  define WIN32_LEAN_AND_MEAN
  56 #  include <windows.h>
  57 # endif
  58 #elif defined WINDOWS_NATIVE
  59 # define WIN32_LEAN_AND_MEAN
  60 # include <windows.h>
  61   /* For the use of setlocale() below, the Gnulib override in setlocale.c is
  62      not needed; see the platform lists in setlocale_null.m4.  */
  63 # undef setlocale
  64 #endif
  65 #if defined OS2
  66 # define INCL_DOS
  67 # include <os2.h>
  68 #endif
  69
  70 /* For MB_CUR_MAX_L */
  71 #if defined DARWIN7
  72 # include <xlocale.h>
  73 #endif
  74
  75
  76 #if HAVE_LANGINFO_CODESET || defined WINDOWS_NATIVE || defined OS2
  77
  78 /* On these platforms, we use a mapping from non-canonical encoding name
  79    to GNU canonical encoding name.  */
  80
  81 /* With glibc-2.1 or newer, we don't need any canonicalization,
  82    because glibc has iconv and both glibc and libiconv support all
  83    GNU canonical names directly.  */
  84 # if !((defined __GNU_LIBRARY__ && __GLIBC__ >= 2) || defined __UCLIBC__)
  85
  86 struct table_entry
  87 {
  88   const char alias[11+1];
  89   const char canonical[11+1];
  90 };
  91
  92 /* Table of platform-dependent mappings, sorted in ascending order.  */
  93 static const struct table_entry alias_table[] =
  94   {
  95 #  if defined __FreeBSD__                                   /* FreeBSD */
  96   /*{ "ARMSCII-8",  "ARMSCII-8" },*/
  97     { "Big5",       "BIG5" },
  98     { "C",          "ASCII" },
  99   /*{ "CP1131",     "CP1131" },*/
 100   /*{ "CP1251",     "CP1251" },*/
 101   /*{ "CP866",      "CP866" },*/
 102   /*{ "GB18030",    "GB18030" },*/
 103   /*{ "GB2312",     "GB2312" },*/
 104   /*{ "GBK",        "GBK" },*/
 105   /*{ "ISCII-DEV",  "?" },*/
 106     { "ISO8859-1",  "ISO-8859-1" },
 107     { "ISO8859-13", "ISO-8859-13" },
 108     { "ISO8859-15", "ISO-8859-15" },
 109     { "ISO8859-2",  "ISO-8859-2" },
 110     { "ISO8859-5",  "ISO-8859-5" },
 111     { "ISO8859-7",  "ISO-8859-7" },
 112     { "ISO8859-9",  "ISO-8859-9" },
 113   /*{ "KOI8-R",     "KOI8-R" },*/
 114   /*{ "KOI8-U",     "KOI8-U" },*/
 115     { "SJIS",       "SHIFT_JIS" },
 116     { "US-ASCII",   "ASCII" },
 117     { "eucCN",      "GB2312" },
 118     { "eucJP",      "EUC-JP" },
 119     { "eucKR",      "EUC-KR" }
 120 #   define alias_table_defined
 121 #  endif
 122 #  if defined __NetBSD__                                    /* NetBSD */
 123     { "646",        "ASCII" },
 124   /*{ "ARMSCII-8",  "ARMSCII-8" },*/
 125   /*{ "BIG5",       "BIG5" },*/
 126     { "Big5-HKSCS", "BIG5-HKSCS" },
 127   /*{ "CP1251",     "CP1251" },*/
 128   /*{ "CP866",      "CP866" },*/
 129   /*{ "GB18030",    "GB18030" },*/
 130   /*{ "GB2312",     "GB2312" },*/
 131     { "ISO8859-1",  "ISO-8859-1" },
 132     { "ISO8859-13", "ISO-8859-13" },
 133     { "ISO8859-15", "ISO-8859-15" },
 134     { "ISO8859-2",  "ISO-8859-2" },
 135     { "ISO8859-4",  "ISO-8859-4" },
 136     { "ISO8859-5",  "ISO-8859-5" },
 137     { "ISO8859-7",  "ISO-8859-7" },
 138   /*{ "KOI8-R",     "KOI8-R" },*/
 139   /*{ "KOI8-U",     "KOI8-U" },*/
 140   /*{ "PT154",      "PT154" },*/
 141     { "SJIS",       "SHIFT_JIS" },
 142     { "eucCN",      "GB2312" },
 143     { "eucJP",      "EUC-JP" },
 144     { "eucKR",      "EUC-KR" },
 145     { "eucTW",      "EUC-TW" }
 146 #   define alias_table_defined
 147 #  endif
 148 #  if defined __OpenBSD__                                   /* OpenBSD */
 149     { "646",        "ASCII" },
 150     { "ISO8859-1",  "ISO-8859-1" },
 151     { "ISO8859-13", "ISO-8859-13" },
 152     { "ISO8859-15", "ISO-8859-15" },
 153     { "ISO8859-2",  "ISO-8859-2" },
 154     { "ISO8859-4",  "ISO-8859-4" },
 155     { "ISO8859-5",  "ISO-8859-5" },
 156     { "ISO8859-7",  "ISO-8859-7" },
 157     { "US-ASCII",   "ASCII" }
 158 #   define alias_table_defined
 159 #  endif
 160 #  if defined __APPLE__ && defined __MACH__                 /* Mac OS X */
 161     /* Darwin 7.5 has nl_langinfo(CODESET), but sometimes its value is
 162        useless:
 163        - It returns the empty string when LANG is set to a locale of the
 164          form ll_CC, although ll_CC/LC_CTYPE is a symlink to an UTF-8
 165          LC_CTYPE file.
 166        - The environment variables LANG, LC_CTYPE, LC_ALL are not set by
 167          the system; nl_langinfo(CODESET) returns "US-ASCII" in this case.
 168        - The documentation says:
 169            "... all code that calls BSD system routines should ensure
 170             that the const *char parameters of these routines are in UTF-8
 171             encoding. All BSD system functions expect their string
 172             parameters to be in UTF-8 encoding and nothing else."
 173          It also says
 174            "An additional caveat is that string parameters for files,
 175             paths, and other file-system entities must be in canonical
 176             UTF-8. In a canonical UTF-8 Unicode string, all decomposable
 177             characters are decomposed ..."
 178          but this is not true: You can pass non-decomposed UTF-8 strings
 179          to file system functions, and it is the OS which will convert
 180          them to decomposed UTF-8 before accessing the file system.
 181        - The Apple Terminal application displays UTF-8 by default.
 182        - However, other applications are free to use different encodings:
 183          - xterm uses ISO-8859-1 by default.
 184          - TextEdit uses MacRoman by default.
 185        We prefer UTF-8 over decomposed UTF-8-MAC because one should
 186        minimize the use of decomposed Unicode. Unfortunately, through the
 187        Darwin file system, decomposed UTF-8 strings are leaked into user
 188        space nevertheless.
 189        Then there are also the locales with encodings other than US-ASCII
 190        and UTF-8. These locales can be occasionally useful to users (e.g.
 191        when grepping through ISO-8859-1 encoded text files), when all their
 192        file names are in US-ASCII.
 193      */
 194     { "ARMSCII-8",  "ARMSCII-8" },
 195     { "Big5",       "BIG5" },
 196     { "Big5HKSCS",  "BIG5-HKSCS" },
 197     { "CP1131",     "CP1131" },
 198     { "CP1251",     "CP1251" },
 199     { "CP866",      "CP866" },
 200     { "CP949",      "CP949" },
 201     { "GB18030",    "GB18030" },
 202     { "GB2312",     "GB2312" },
 203     { "GBK",        "GBK" },
 204   /*{ "ISCII-DEV",  "?" },*/
 205     { "ISO8859-1",  "ISO-8859-1" },
 206     { "ISO8859-13", "ISO-8859-13" },
 207     { "ISO8859-15", "ISO-8859-15" },
 208     { "ISO8859-2",  "ISO-8859-2" },
 209     { "ISO8859-4",  "ISO-8859-4" },
 210     { "ISO8859-5",  "ISO-8859-5" },
 211     { "ISO8859-7",  "ISO-8859-7" },
 212     { "ISO8859-9",  "ISO-8859-9" },
 213     { "KOI8-R",     "KOI8-R" },
 214     { "KOI8-U",     "KOI8-U" },
 215     { "PT154",      "PT154" },
 216     { "SJIS",       "SHIFT_JIS" },
 217     { "eucCN",      "GB2312" },
 218     { "eucJP",      "EUC-JP" },
 219     { "eucKR",      "EUC-KR" }
 220 #   define alias_table_defined
 221 #  endif
 222 #  if defined _AIX                                          /* AIX */
 223   /*{ "GBK",        "GBK" },*/
 224     { "IBM-1046",   "CP1046" },
 225     { "IBM-1124",   "CP1124" },
 226     { "IBM-1129",   "CP1129" },
 227     { "IBM-1252",   "CP1252" },
 228     { "IBM-850",    "CP850" },
 229     { "IBM-856",    "CP856" },
 230     { "IBM-921",    "ISO-8859-13" },
 231     { "IBM-922",    "CP922" },
 232     { "IBM-932",    "CP932" },
 233     { "IBM-943",    "CP943" },
 234     { "IBM-eucCN",  "GB2312" },
 235     { "IBM-eucJP",  "EUC-JP" },
 236     { "IBM-eucKR",  "EUC-KR" },
 237     { "IBM-eucTW",  "EUC-TW" },
 238     { "ISO8859-1",  "ISO-8859-1" },
 239     { "ISO8859-15", "ISO-8859-15" },
 240     { "ISO8859-2",  "ISO-8859-2" },
 241     { "ISO8859-5",  "ISO-8859-5" },
 242     { "ISO8859-6",  "ISO-8859-6" },
 243     { "ISO8859-7",  "ISO-8859-7" },
 244     { "ISO8859-8",  "ISO-8859-8" },
 245     { "ISO8859-9",  "ISO-8859-9" },
 246     { "TIS-620",    "TIS-620" },
 247   /*{ "UTF-8",      "UTF-8" },*/
 248     { "big5",       "BIG5" }
 249 #   define alias_table_defined
 250 #  endif
 251 #  if defined __hpux                                        /* HP-UX */
 252     { "SJIS",      "SHIFT_JIS" },
 253     { "arabic8",   "HP-ARABIC8" },
 254     { "big5",      "BIG5" },
 255     { "cp1251",    "CP1251" },
 256     { "eucJP",     "EUC-JP" },
 257     { "eucKR",     "EUC-KR" },
 258     { "eucTW",     "EUC-TW" },
 259     { "gb18030",   "GB18030" },
 260     { "greek8",    "HP-GREEK8" },
 261     { "hebrew8",   "HP-HEBREW8" },
 262     { "hkbig5",    "BIG5-HKSCS" },
 263     { "hp15CN",    "GB2312" },
 264     { "iso88591",  "ISO-8859-1" },
 265     { "iso885913", "ISO-8859-13" },
 266     { "iso885915", "ISO-8859-15" },
 267     { "iso88592",  "ISO-8859-2" },
 268     { "iso88594",  "ISO-8859-4" },
 269     { "iso88595",  "ISO-8859-5" },
 270     { "iso88596",  "ISO-8859-6" },
 271     { "iso88597",  "ISO-8859-7" },
 272     { "iso88598",  "ISO-8859-8" },
 273     { "iso88599",  "ISO-8859-9" },
 274     { "kana8",     "HP-KANA8" },
 275     { "koi8r",     "KOI8-R" },
 276     { "roman8",    "HP-ROMAN8" },
 277     { "tis620",    "TIS-620" },
 278     { "turkish8",  "HP-TURKISH8" },
 279     { "utf8",      "UTF-8" }
 280 #   define alias_table_defined
 281 #  endif
 282 #  if defined __sgi                                         /* IRIX */
 283     { "ISO8859-1",  "ISO-8859-1" },
 284     { "ISO8859-15", "ISO-8859-15" },
 285     { "ISO8859-2",  "ISO-8859-2" },
 286     { "ISO8859-5",  "ISO-8859-5" },
 287     { "ISO8859-7",  "ISO-8859-7" },
 288     { "ISO8859-9",  "ISO-8859-9" },
 289     { "eucCN",      "GB2312" },
 290     { "eucJP",      "EUC-JP" },
 291     { "eucKR",      "EUC-KR" },
 292     { "eucTW",      "EUC-TW" }
 293 #   define alias_table_defined
 294 #  endif
 295 #  if defined __osf__                                       /* OSF/1 */
 296   /*{ "GBK",        "GBK" },*/
 297     { "ISO8859-1",  "ISO-8859-1" },
 298     { "ISO8859-15", "ISO-8859-15" },
 299     { "ISO8859-2",  "ISO-8859-2" },
 300     { "ISO8859-4",  "ISO-8859-4" },
 301     { "ISO8859-5",  "ISO-8859-5" },
 302     { "ISO8859-7",  "ISO-8859-7" },
 303     { "ISO8859-8",  "ISO-8859-8" },
 304     { "ISO8859-9",  "ISO-8859-9" },
 305     { "KSC5601",    "CP949" },
 306     { "SJIS",       "SHIFT_JIS" },
 307     { "TACTIS",     "TIS-620" },
 308   /*{ "UTF-8",      "UTF-8" },*/
 309     { "big5",       "BIG5" },
 310     { "cp850",      "CP850" },
 311     { "dechanyu",   "DEC-HANYU" },
 312     { "dechanzi",   "GB2312" },
 313     { "deckanji",   "DEC-KANJI" },
 314     { "deckorean",  "EUC-KR" },
 315     { "eucJP",      "EUC-JP" },
 316     { "eucKR",      "EUC-KR" },
 317     { "eucTW",      "EUC-TW" },
 318     { "sdeckanji",  "EUC-JP" }
 319 #   define alias_table_defined
 320 #  endif
 321 #  if defined __sun                                         /* Solaris */
 322     { "5601",        "EUC-KR" },
 323     { "646",         "ASCII" },
 324   /*{ "BIG5",        "BIG5" },*/
 325     { "Big5-HKSCS",  "BIG5-HKSCS" },
 326     { "GB18030",     "GB18030" },
 327   /*{ "GBK",         "GBK" },*/
 328     { "ISO8859-1",   "ISO-8859-1" },
 329     { "ISO8859-11",  "TIS-620" },
 330     { "ISO8859-13",  "ISO-8859-13" },
 331     { "ISO8859-15",  "ISO-8859-15" },
 332     { "ISO8859-2",   "ISO-8859-2" },
 333     { "ISO8859-3",   "ISO-8859-3" },
 334     { "ISO8859-4",   "ISO-8859-4" },
 335     { "ISO8859-5",   "ISO-8859-5" },
 336     { "ISO8859-6",   "ISO-8859-6" },
 337     { "ISO8859-7",   "ISO-8859-7" },
 338     { "ISO8859-8",   "ISO-8859-8" },
 339     { "ISO8859-9",   "ISO-8859-9" },
 340     { "PCK",         "SHIFT_JIS" },
 341     { "TIS620.2533", "TIS-620" },
 342   /*{ "UTF-8",       "UTF-8" },*/
 343     { "ansi-1251",   "CP1251" },
 344     { "cns11643",    "EUC-TW" },
 345     { "eucJP",       "EUC-JP" },
 346     { "gb2312",      "GB2312" },
 347     { "koi8-r",      "KOI8-R" }
 348 #   define alias_table_defined
 349 #  endif
 350 #  if defined __minix                                       /* Minix */
 351     { "646", "ASCII" }
 352 #   define alias_table_defined
 353 #  endif
 354 #  if defined WINDOWS_NATIVE || defined __CYGWIN__          /* Windows */
 355     { "CP1361",  "JOHAB" },
 356     { "CP20127", "ASCII" },
 357     { "CP20866", "KOI8-R" },
 358     { "CP20936", "GB2312" },
 359     { "CP21866", "KOI8-RU" },
 360     { "CP28591", "ISO-8859-1" },
 361     { "CP28592", "ISO-8859-2" },
 362     { "CP28593", "ISO-8859-3" },
 363     { "CP28594", "ISO-8859-4" },
 364     { "CP28595", "ISO-8859-5" },
 365     { "CP28596", "ISO-8859-6" },
 366     { "CP28597", "ISO-8859-7" },
 367     { "CP28598", "ISO-8859-8" },
 368     { "CP28599", "ISO-8859-9" },
 369     { "CP28605", "ISO-8859-15" },
 370     { "CP38598", "ISO-8859-8" },
 371     { "CP51932", "EUC-JP" },
 372     { "CP51936", "GB2312" },
 373     { "CP51949", "EUC-KR" },
 374     { "CP51950", "EUC-TW" },
 375     { "CP54936", "GB18030" },
 376     { "CP65001", "UTF-8" },
 377     { "CP936",   "GBK" }
 378 #   define alias_table_defined
 379 #  endif
 380 #  if defined OS2                                           /* OS/2 */
 381     /* The list of encodings is taken from "List of OS/2 Codepages"
 382        by Alex Taylor:
 383        <https://altsan.org/os2/toolkits/uls/index.html#codepages>.
 384        See also "__convcp() of kLIBC":
 385        <https://github.com/bitwiseworks/libc/blob/master/src/emx/src/lib/locale/__convcp.c>.  */
 386     { "CP1004",        "CP1252" },
 387   /*{ "CP1041",        "CP943" },*/
 388   /*{ "CP1088",        "CP949" },*/
 389     { "CP1089",        "ISO-8859-6" },
 390   /*{ "CP1114",        "CP950" },*/
 391   /*{ "CP1115",        "GB2312" },*/
 392     { "CP1208",        "UTF-8" },
 393   /*{ "CP1380",        "GB2312" },*/
 394     { "CP1381",        "GB2312" },
 395     { "CP1383",        "GB2312" },
 396     { "CP1386",        "GBK" },
 397   /*{ "CP301",         "CP943" },*/
 398     { "CP3372",        "EUC-JP" },
 399     { "CP4946",        "CP850" },
 400   /*{ "CP5048",        "JIS_X0208-1990" },*/
 401   /*{ "CP5049",        "JIS_X0212-1990" },*/
 402   /*{ "CP5067",        "KS_C_5601-1987" },*/
 403     { "CP813",         "ISO-8859-7" },
 404     { "CP819",         "ISO-8859-1" },
 405     { "CP878",         "KOI8-R" },
 406   /*{ "CP897",         "CP943" },*/
 407     { "CP912",         "ISO-8859-2" },
 408     { "CP913",         "ISO-8859-3" },
 409     { "CP914",         "ISO-8859-4" },
 410     { "CP915",         "ISO-8859-5" },
 411     { "CP916",         "ISO-8859-8" },
 412     { "CP920",         "ISO-8859-9" },
 413     { "CP921",         "ISO-8859-13" },
 414     { "CP923",         "ISO-8859-15" },
 415   /*{ "CP941",         "CP943" },*/
 416   /*{ "CP947",         "CP950" },*/
 417   /*{ "CP951",         "CP949" },*/
 418   /*{ "CP952",         "JIS_X0208-1990" },*/
 419   /*{ "CP953",         "JIS_X0212-1990" },*/
 420     { "CP954",         "EUC-JP" },
 421     { "CP964",         "EUC-TW" },
 422     { "CP970",         "EUC-KR" },
 423   /*{ "CP971",         "KS_C_5601-1987" },*/
 424     { "IBM-1004",      "CP1252" },
 425   /*{ "IBM-1006",      "?" },*/
 426   /*{ "IBM-1008",      "?" },*/
 427   /*{ "IBM-1041",      "CP943" },*/
 428   /*{ "IBM-1051",      "?" },*/
 429   /*{ "IBM-1088",      "CP949" },*/
 430     { "IBM-1089",      "ISO-8859-6" },
 431   /*{ "IBM-1098",      "?" },*/
 432   /*{ "IBM-1114",      "CP950" },*/
 433   /*{ "IBM-1115",      "GB2312" },*/
 434   /*{ "IBM-1116",      "?" },*/
 435   /*{ "IBM-1117",      "?" },*/
 436   /*{ "IBM-1118",      "?" },*/
 437   /*{ "IBM-1119",      "?" },*/
 438     { "IBM-1124",      "CP1124" },
 439     { "IBM-1125",      "CP1125" },
 440     { "IBM-1131",      "CP1131" },
 441     { "IBM-1208",      "UTF-8" },
 442     { "IBM-1250",      "CP1250" },
 443     { "IBM-1251",      "CP1251" },
 444     { "IBM-1252",      "CP1252" },
 445     { "IBM-1253",      "CP1253" },
 446     { "IBM-1254",      "CP1254" },
 447     { "IBM-1255",      "CP1255" },
 448     { "IBM-1256",      "CP1256" },
 449     { "IBM-1257",      "CP1257" },
 450   /*{ "IBM-1275",      "?" },*/
 451   /*{ "IBM-1276",      "?" },*/
 452   /*{ "IBM-1277",      "?" },*/
 453   /*{ "IBM-1280",      "?" },*/
 454   /*{ "IBM-1281",      "?" },*/
 455   /*{ "IBM-1282",      "?" },*/
 456   /*{ "IBM-1283",      "?" },*/
 457   /*{ "IBM-1380",      "GB2312" },*/
 458     { "IBM-1381",      "GB2312" },
 459     { "IBM-1383",      "GB2312" },
 460     { "IBM-1386",      "GBK" },
 461   /*{ "IBM-301",       "CP943" },*/
 462     { "IBM-3372",      "EUC-JP" },
 463     { "IBM-367",       "ASCII" },
 464     { "IBM-437",       "CP437" },
 465     { "IBM-4946",      "CP850" },
 466   /*{ "IBM-5048",      "JIS_X0208-1990" },*/
 467   /*{ "IBM-5049",      "JIS_X0212-1990" },*/
 468   /*{ "IBM-5067",      "KS_C_5601-1987" },*/
 469     { "IBM-813",       "ISO-8859-7" },
 470     { "IBM-819",       "ISO-8859-1" },
 471     { "IBM-850",       "CP850" },
 472   /*{ "IBM-851",       "?" },*/
 473     { "IBM-852",       "CP852" },
 474     { "IBM-855",       "CP855" },
 475     { "IBM-856",       "CP856" },
 476     { "IBM-857",       "CP857" },
 477   /*{ "IBM-859",       "?" },*/
 478     { "IBM-860",       "CP860" },
 479     { "IBM-861",       "CP861" },
 480     { "IBM-862",       "CP862" },
 481     { "IBM-863",       "CP863" },
 482     { "IBM-864",       "CP864" },
 483     { "IBM-865",       "CP865" },
 484     { "IBM-866",       "CP866" },
 485   /*{ "IBM-868",       "?" },*/
 486     { "IBM-869",       "CP869" },
 487     { "IBM-874",       "CP874" },
 488     { "IBM-878",       "KOI8-R" },
 489   /*{ "IBM-895",       "?" },*/
 490   /*{ "IBM-897",       "CP943" },*/
 491   /*{ "IBM-907",       "?" },*/
 492   /*{ "IBM-909",       "?" },*/
 493     { "IBM-912",       "ISO-8859-2" },
 494     { "IBM-913",       "ISO-8859-3" },
 495     { "IBM-914",       "ISO-8859-4" },
 496     { "IBM-915",       "ISO-8859-5" },
 497     { "IBM-916",       "ISO-8859-8" },
 498     { "IBM-920",       "ISO-8859-9" },
 499     { "IBM-921",       "ISO-8859-13" },
 500     { "IBM-922",       "CP922" },
 501     { "IBM-923",       "ISO-8859-15" },
 502     { "IBM-932",       "CP932" },
 503   /*{ "IBM-941",       "CP943" },*/
 504   /*{ "IBM-942",       "?" },*/
 505     { "IBM-943",       "CP943" },
 506   /*{ "IBM-947",       "CP950" },*/
 507     { "IBM-949",       "CP949" },
 508     { "IBM-950",       "CP950" },
 509   /*{ "IBM-951",       "CP949" },*/
 510   /*{ "IBM-952",       "JIS_X0208-1990" },*/
 511   /*{ "IBM-953",       "JIS_X0212-1990" },*/
 512     { "IBM-954",       "EUC-JP" },
 513   /*{ "IBM-955",       "?" },*/
 514     { "IBM-964",       "EUC-TW" },
 515     { "IBM-970",       "EUC-KR" },
 516   /*{ "IBM-971",       "KS_C_5601-1987" },*/
 517     { "IBM-eucCN",     "GB2312" },
 518     { "IBM-eucJP",     "EUC-JP" },
 519     { "IBM-eucKR",     "EUC-KR" },
 520     { "IBM-eucTW",     "EUC-TW" },
 521     { "IBM33722",      "EUC-JP" },
 522     { "ISO8859-1",     "ISO-8859-1" },
 523     { "ISO8859-2",     "ISO-8859-2" },
 524     { "ISO8859-3",     "ISO-8859-3" },
 525     { "ISO8859-4",     "ISO-8859-4" },
 526     { "ISO8859-5",     "ISO-8859-5" },
 527     { "ISO8859-6",     "ISO-8859-6" },
 528     { "ISO8859-7",     "ISO-8859-7" },
 529     { "ISO8859-8",     "ISO-8859-8" },
 530     { "ISO8859-9",     "ISO-8859-9" },
 531   /*{ "JISX0201-1976", "JISX0201-1976" },*/
 532   /*{ "JISX0208-1978", "?" },*/
 533   /*{ "JISX0208-1983", "JIS_X0208-1983" },*/
 534   /*{ "JISX0208-1990", "JIS_X0208-1990" },*/
 535   /*{ "JISX0212-1990", "JIS_X0212-1990" },*/
 536   /*{ "KSC5601-1987",  "KS_C_5601-1987" },*/
 537     { "SJIS-1",        "CP943" },
 538     { "SJIS-2",        "CP943" },
 539     { "eucJP",         "EUC-JP" },
 540     { "eucKR",         "EUC-KR" },
 541     { "eucTW-1993",    "EUC-TW" }
 542 #   define alias_table_defined
 543 #  endif
 544 #  if defined VMS                                           /* OpenVMS */
 545     /* The list of encodings is taken from the OpenVMS 7.3-1 documentation
 546        "Compaq C Run-Time Library Reference Manual for OpenVMS systems"
 547        section 10.7 "Handling Different Character Sets".  */
 548     { "DECHANYU",  "DEC-HANYU" },
 549     { "DECHANZI",  "GB2312" },
 550     { "DECKANJI",  "DEC-KANJI" },
 551     { "DECKOREAN", "EUC-KR" },
 552     { "ISO8859-1", "ISO-8859-1" },
 553     { "ISO8859-2", "ISO-8859-2" },
 554     { "ISO8859-5", "ISO-8859-5" },
 555     { "ISO8859-7", "ISO-8859-7" },
 556     { "ISO8859-8", "ISO-8859-8" },
 557     { "ISO8859-9", "ISO-8859-9" },
 558     { "SDECKANJI", "EUC-JP" },
 559     { "SJIS",      "SHIFT_JIS" },
 560     { "eucJP",     "EUC-JP" },
 561     { "eucTW",     "EUC-TW" }
 562 #   define alias_table_defined
 563 #  endif
 564 #  ifndef alias_table_defined
 565     /* Just a dummy entry, to avoid a C syntax error.  */
 566     { "", "" }
 567 #  endif
 568   };
 569
 570 # endif
 571
 572 #else
 573
 574 /* On these platforms, we use a mapping from locale name to GNU canonical
 575    encoding name.  */
 576
 577 struct table_entry
 578 {
 579   const char locale[17+1];
 580   const char canonical[11+1];
 581 };
 582
 583 /* Table of platform-dependent mappings, sorted in ascending order.  */
 584 static const struct table_entry locale_table[] =
 585   {
 586 # if defined __FreeBSD__                                    /* FreeBSD 4.2 */
 587     { "cs_CZ.ISO_8859-2",  "ISO-8859-2" },
 588     { "da_DK.DIS_8859-15", "ISO-8859-15" },
 589     { "da_DK.ISO_8859-1",  "ISO-8859-1" },
 590     { "de_AT.DIS_8859-15", "ISO-8859-15" },
 591     { "de_AT.ISO_8859-1",  "ISO-8859-1" },
 592     { "de_CH.DIS_8859-15", "ISO-8859-15" },
 593     { "de_CH.ISO_8859-1",  "ISO-8859-1" },
 594     { "de_DE.DIS_8859-15", "ISO-8859-15" },
 595     { "de_DE.ISO_8859-1",  "ISO-8859-1" },
 596     { "en_AU.DIS_8859-15", "ISO-8859-15" },
 597     { "en_AU.ISO_8859-1",  "ISO-8859-1" },
 598     { "en_CA.DIS_8859-15", "ISO-8859-15" },
 599     { "en_CA.ISO_8859-1",  "ISO-8859-1" },
 600     { "en_GB.DIS_8859-15", "ISO-8859-15" },
 601     { "en_GB.ISO_8859-1",  "ISO-8859-1" },
 602     { "en_US.DIS_8859-15", "ISO-8859-15" },
 603     { "en_US.ISO_8859-1",  "ISO-8859-1" },
 604     { "es_ES.DIS_8859-15", "ISO-8859-15" },
 605     { "es_ES.ISO_8859-1",  "ISO-8859-1" },
 606     { "fi_FI.DIS_8859-15", "ISO-8859-15" },
 607     { "fi_FI.ISO_8859-1",  "ISO-8859-1" },
 608     { "fr_BE.DIS_8859-15", "ISO-8859-15" },
 609     { "fr_BE.ISO_8859-1",  "ISO-8859-1" },
 610     { "fr_CA.DIS_8859-15", "ISO-8859-15" },
 611     { "fr_CA.ISO_8859-1",  "ISO-8859-1" },
 612     { "fr_CH.DIS_8859-15", "ISO-8859-15" },
 613     { "fr_CH.ISO_8859-1",  "ISO-8859-1" },
 614     { "fr_FR.DIS_8859-15", "ISO-8859-15" },
 615     { "fr_FR.ISO_8859-1",  "ISO-8859-1" },
 616     { "hr_HR.ISO_8859-2",  "ISO-8859-2" },
 617     { "hu_HU.ISO_8859-2",  "ISO-8859-2" },
 618     { "is_IS.DIS_8859-15", "ISO-8859-15" },
 619     { "is_IS.ISO_8859-1",  "ISO-8859-1" },
 620     { "it_CH.DIS_8859-15", "ISO-8859-15" },
 621     { "it_CH.ISO_8859-1",  "ISO-8859-1" },
 622     { "it_IT.DIS_8859-15", "ISO-8859-15" },
 623     { "it_IT.ISO_8859-1",  "ISO-8859-1" },
 624     { "ja_JP.EUC",         "EUC-JP" },
 625     { "ja_JP.SJIS",        "SHIFT_JIS" },
 626     { "ja_JP.Shift_JIS",   "SHIFT_JIS" },
 627     { "ko_KR.EUC",         "EUC-KR" },
 628     { "la_LN.ASCII",       "ASCII" },
 629     { "la_LN.DIS_8859-15", "ISO-8859-15" },
 630     { "la_LN.ISO_8859-1",  "ISO-8859-1" },
 631     { "la_LN.ISO_8859-2",  "ISO-8859-2" },
 632     { "la_LN.ISO_8859-4",  "ISO-8859-4" },
 633     { "lt_LN.ASCII",       "ASCII" },
 634     { "lt_LN.DIS_8859-15", "ISO-8859-15" },
 635     { "lt_LN.ISO_8859-1",  "ISO-8859-1" },
 636     { "lt_LN.ISO_8859-2",  "ISO-8859-2" },
 637     { "lt_LT.ISO_8859-4",  "ISO-8859-4" },
 638     { "nl_BE.DIS_8859-15", "ISO-8859-15" },
 639     { "nl_BE.ISO_8859-1",  "ISO-8859-1" },
 640     { "nl_NL.DIS_8859-15", "ISO-8859-15" },
 641     { "nl_NL.ISO_8859-1",  "ISO-8859-1" },
 642     { "no_NO.DIS_8859-15", "ISO-8859-15" },
 643     { "no_NO.ISO_8859-1",  "ISO-8859-1" },
 644     { "pl_PL.ISO_8859-2",  "ISO-8859-2" },
 645     { "pt_PT.DIS_8859-15", "ISO-8859-15" },
 646     { "pt_PT.ISO_8859-1",  "ISO-8859-1" },
 647     { "ru_RU.CP866",       "CP866" },
 648     { "ru_RU.ISO_8859-5",  "ISO-8859-5" },
 649     { "ru_RU.KOI8-R",      "KOI8-R" },
 650     { "ru_SU.CP866",       "CP866" },
 651     { "ru_SU.ISO_8859-5",  "ISO-8859-5" },
 652     { "ru_SU.KOI8-R",      "KOI8-R" },
 653     { "sl_SI.ISO_8859-2",  "ISO-8859-2" },
 654     { "sv_SE.DIS_8859-15", "ISO-8859-15" },
 655     { "sv_SE.ISO_8859-1",  "ISO-8859-1" },
 656     { "uk_UA.KOI8-U",      "KOI8-U" },
 657     { "zh_CN.EUC",         "GB2312" },
 658     { "zh_TW.BIG5",        "BIG5" },
 659     { "zh_TW.Big5",        "BIG5" }
 660 #  define locale_table_defined
 661 # endif
 662 # if defined __DJGPP__                                      /* DOS / DJGPP 2.03 */
 663     /* The encodings given here may not all be correct.
 664        If you find that the encoding given for your language and
 665        country is not the one your DOS machine actually uses, just
 666        correct it in this file, and send a mail to
 667        Juan Manuel Guerrero <juan.guerrero@gmx.de>
 668        and <bug-gnulib@gnu.org>.  */
 669     { "C",     "ASCII" },
 670     { "ar",    "CP864" },
 671     { "ar_AE", "CP864" },
 672     { "ar_DZ", "CP864" },
 673     { "ar_EG", "CP864" },
 674     { "ar_IQ", "CP864" },
 675     { "ar_IR", "CP864" },
 676     { "ar_JO", "CP864" },
 677     { "ar_KW", "CP864" },
 678     { "ar_MA", "CP864" },
 679     { "ar_OM", "CP864" },
 680     { "ar_QA", "CP864" },
 681     { "ar_SA", "CP864" },
 682     { "ar_SY", "CP864" },
 683     { "be",    "CP866" },
 684     { "be_BE", "CP866" },
 685     { "bg",    "CP866" }, /* not CP855 ?? */
 686     { "bg_BG", "CP866" }, /* not CP855 ?? */
 687     { "ca",    "CP850" },
 688     { "ca_ES", "CP850" },
 689     { "cs",    "CP852" },
 690     { "cs_CZ", "CP852" },
 691     { "da",    "CP865" }, /* not CP850 ?? */
 692     { "da_DK", "CP865" }, /* not CP850 ?? */
 693     { "de",    "CP850" },
 694     { "de_AT", "CP850" },
 695     { "de_CH", "CP850" },
 696     { "de_DE", "CP850" },
 697     { "el",    "CP869" },
 698     { "el_GR", "CP869" },
 699     { "en",    "CP850" },
 700     { "en_AU", "CP850" }, /* not CP437 ?? */
 701     { "en_CA", "CP850" },
 702     { "en_GB", "CP850" },
 703     { "en_NZ", "CP437" },
 704     { "en_US", "CP437" },
 705     { "en_ZA", "CP850" }, /* not CP437 ?? */
 706     { "eo",    "CP850" },
 707     { "eo_EO", "CP850" },
 708     { "es",    "CP850" },
 709     { "es_AR", "CP850" },
 710     { "es_BO", "CP850" },
 711     { "es_CL", "CP850" },
 712     { "es_CO", "CP850" },
 713     { "es_CR", "CP850" },
 714     { "es_CU", "CP850" },
 715     { "es_DO", "CP850" },
 716     { "es_EC", "CP850" },
 717     { "es_ES", "CP850" },
 718     { "es_GT", "CP850" },
 719     { "es_HN", "CP850" },
 720     { "es_MX", "CP850" },
 721     { "es_NI", "CP850" },
 722     { "es_PA", "CP850" },
 723     { "es_PE", "CP850" },
 724     { "es_PY", "CP850" },
 725     { "es_SV", "CP850" },
 726     { "es_UY", "CP850" },
 727     { "es_VE", "CP850" },
 728     { "et",    "CP850" },
 729     { "et_EE", "CP850" },
 730     { "eu",    "CP850" },
 731     { "eu_ES", "CP850" },
 732     { "fi",    "CP850" },
 733     { "fi_FI", "CP850" },
 734     { "fr",    "CP850" },
 735     { "fr_BE", "CP850" },
 736     { "fr_CA", "CP850" },
 737     { "fr_CH", "CP850" },
 738     { "fr_FR", "CP850" },
 739     { "ga",    "CP850" },
 740     { "ga_IE", "CP850" },
 741     { "gd",    "CP850" },
 742     { "gd_GB", "CP850" },
 743     { "gl",    "CP850" },
 744     { "gl_ES", "CP850" },
 745     { "he",    "CP862" },
 746     { "he_IL", "CP862" },
 747     { "hr",    "CP852" },
 748     { "hr_HR", "CP852" },
 749     { "hu",    "CP852" },
 750     { "hu_HU", "CP852" },
 751     { "id",    "CP850" }, /* not CP437 ?? */
 752     { "id_ID", "CP850" }, /* not CP437 ?? */
 753     { "is",    "CP861" }, /* not CP850 ?? */
 754     { "is_IS", "CP861" }, /* not CP850 ?? */
 755     { "it",    "CP850" },
 756     { "it_CH", "CP850" },
 757     { "it_IT", "CP850" },
 758     { "ja",    "CP932" },
 759     { "ja_JP", "CP932" },
 760     { "kr",    "CP949" }, /* not CP934 ?? */
 761     { "kr_KR", "CP949" }, /* not CP934 ?? */
 762     { "lt",    "CP775" },
 763     { "lt_LT", "CP775" },
 764     { "lv",    "CP775" },
 765     { "lv_LV", "CP775" },
 766     { "mk",    "CP866" }, /* not CP855 ?? */
 767     { "mk_MK", "CP866" }, /* not CP855 ?? */
 768     { "mt",    "CP850" },
 769     { "mt_MT", "CP850" },
 770     { "nb",    "CP865" }, /* not CP850 ?? */
 771     { "nb_NO", "CP865" }, /* not CP850 ?? */
 772     { "nl",    "CP850" },
 773     { "nl_BE", "CP850" },
 774     { "nl_NL", "CP850" },
 775     { "nn",    "CP865" }, /* not CP850 ?? */
 776     { "nn_NO", "CP865" }, /* not CP850 ?? */
 777     { "no",    "CP865" }, /* not CP850 ?? */
 778     { "no_NO", "CP865" }, /* not CP850 ?? */
 779     { "pl",    "CP852" },
 780     { "pl_PL", "CP852" },
 781     { "pt",    "CP850" },
 782     { "pt_BR", "CP850" },
 783     { "pt_PT", "CP850" },
 784     { "ro",    "CP852" },
 785     { "ro_RO", "CP852" },
 786     { "ru",    "CP866" },
 787     { "ru_RU", "CP866" },
 788     { "sk",    "CP852" },
 789     { "sk_SK", "CP852" },
 790     { "sl",    "CP852" },
 791     { "sl_SI", "CP852" },
 792     { "sq",    "CP852" },
 793     { "sq_AL", "CP852" },
 794     { "sr",    "CP852" }, /* CP852 or CP866 or CP855 ?? */
 795     { "sr_CS", "CP852" }, /* CP852 or CP866 or CP855 ?? */
 796     { "sr_YU", "CP852" }, /* CP852 or CP866 or CP855 ?? */
 797     { "sv",    "CP850" },
 798     { "sv_SE", "CP850" },
 799     { "th",    "CP874" },
 800     { "th_TH", "CP874" },
 801     { "tr",    "CP857" },
 802     { "tr_TR", "CP857" },
 803     { "uk",    "CP1125" },
 804     { "uk_UA", "CP1125" },
 805     { "zh_CN", "GBK" },
 806     { "zh_TW", "CP950" } /* not CP938 ?? */
 807 #  define locale_table_defined
 808 # endif
 809 # ifndef locale_table_defined
 810     /* Just a dummy entry, to avoid a C syntax error.  */
 811     { "", "" }
 812 # endif
 813   };
 814
 815 #endif
 816
 817
 818 /* Determine the current locale's character encoding, and canonicalize it
 819    into one of the canonical names listed below.
 820    The result must not be freed; it is statically allocated.  The result
 821    becomes invalid when setlocale() is used to change the global locale, or
 822    when the value of one of the environment variables LC_ALL, LC_CTYPE, LANG
 823    is changed; threads in multithreaded programs should not do this.
 824    If the canonical name cannot be determined, the result is a non-canonical
 825    name.  */
 826
 827 #ifdef STATIC
 828 STATIC
 829 #endif
 830 const char *
 831 locale_charset (void)
 832 {
 833   const char *codeset;
 834
 835   /* This function must be multithread-safe.  To achieve this without using
 836      thread-local storage, we use a simple strcpy or memcpy to fill this static
 837      buffer.  Filling it through, for example, strcpy + strcat would not be
 838      guaranteed to leave the buffer's contents intact if another thread is
 839      currently accessing it.  If necessary, the contents is first assembled in
 840      a stack-allocated buffer.  */
 841
 842 #if HAVE_LANGINFO_CODESET || defined WINDOWS_NATIVE || defined OS2
 843
 844 # if HAVE_LANGINFO_CODESET
 845
 846   /* Most systems support nl_langinfo (CODESET) nowadays.  */
 847   codeset = nl_langinfo (CODESET);
 848
 849 #  ifdef __CYGWIN__
 850   /* Cygwin < 1.7 does not have locales.  nl_langinfo (CODESET) always
 851      returns "US-ASCII".  Return the suffix of the locale name from the
 852      environment variables (if present) or the codepage as a number.  */
 853   if (codeset != NULL && strcmp (codeset, "US-ASCII") == 0)
 854     {
 855       const char *locale;
 856       static char resultbuf[2 + 10 + 1];
 857
 858       locale = getenv ("LC_ALL");
 859       if (locale == NULL || locale[0] == '\0')
 860         {
 861           locale = getenv ("LC_CTYPE");
 862           if (locale == NULL || locale[0] == '\0')
 863             locale = getenv ("LANG");
 864         }
 865       if (locale != NULL && locale[0] != '\0')
 866         {
 867           /* If the locale name contains an encoding after the dot, return
 868              it.  */
 869           const char *dot = strchr (locale, '.');
 870
 871           if (dot != NULL)
 872             {
 873               const char *modifier;
 874
 875               dot++;
 876               /* Look for the possible @... trailer and remove it, if any.  */
 877               modifier = strchr (dot, '@');
 878               if (modifier == NULL)
 879                 return dot;
 880               if (modifier - dot < sizeof (resultbuf))
 881                 {
 882                   /* This way of filling resultbuf is multithread-safe.  */
 883                   memcpy (resultbuf, dot, modifier - dot);
 884                   resultbuf [modifier - dot] = '\0';
 885                   return resultbuf;
 886                 }
 887             }
 888         }
 889
 890       /* The Windows API has a function returning the locale's codepage as a
 891          number: GetACP().  This encoding is used by Cygwin, unless the user
 892          has set the environment variable CYGWIN=codepage:oem (which very few
 893          people do).
 894          Output directed to console windows needs to be converted (to
 895          GetOEMCP() if the console is using a raster font, or to
 896          GetConsoleOutputCP() if it is using a TrueType font).  Cygwin does
 897          this conversion transparently (see winsup/cygwin/fhandler_console.cc),
 898          converting to GetConsoleOutputCP().  This leads to correct results,
 899          except when SetConsoleOutputCP has been called and a raster font is
 900          in use.  */
 901       {
 902         char buf[2 + 10 + 1];
 903
 904         sprintf (buf, "CP%u", GetACP ());
 905         strcpy (resultbuf, buf);
 906         codeset = resultbuf;
 907       }
 908     }
 909 #  endif
 910
 911   if (codeset == NULL)
 912     /* The canonical name cannot be determined.  */
 913     codeset = "";
 914
 915 # elif defined WINDOWS_NATIVE
 916
 917   char buf[2 + 10 + 1];
 918   static char resultbuf[2 + 10 + 1];
 919
 920   /* The Windows API has a function returning the locale's codepage as
 921      a number, but the value doesn't change according to what the
 922      'setlocale' call specified.  So we use it as a last resort, in
 923      case the string returned by 'setlocale' doesn't specify the
 924      codepage.  */
 925   char *current_locale = setlocale (LC_CTYPE, NULL);
 926   char *pdot = strrchr (current_locale, '.');
 927
 928   if (pdot && 2 + strlen (pdot + 1) + 1 <= sizeof (buf))
 929     sprintf (buf, "CP%s", pdot + 1);
 930   else
 931     {
 932       /* The Windows API has a function returning the locale's codepage as a
 933          number: GetACP().
 934          When the output goes to a console window, it needs to be provided in
 935          GetOEMCP() encoding if the console is using a raster font, or in
 936          GetConsoleOutputCP() encoding if it is using a TrueType font.
 937          But in GUI programs and for output sent to files and pipes, GetACP()
 938          encoding is the best bet.  */
 939       sprintf (buf, "CP%u", GetACP ());
 940     }
 941   /* For a locale name such as "French_France.65001", in Windows 10,
 942      setlocale now returns "French_France.utf8" instead.  */
 943   if (strcmp (buf + 2, "65001") == 0 || strcmp (buf + 2, "utf8") == 0)
 944     codeset = "UTF-8";
 945   else
 946     {
 947       strcpy (resultbuf, buf);
 948       codeset = resultbuf;
 949     }
 950
 951 # elif defined OS2
 952
 953   const char *locale;
 954   static char resultbuf[2 + 10 + 1];
 955   ULONG cp[3];
 956   ULONG cplen;
 957
 958   codeset = NULL;
 959
 960   /* Allow user to override the codeset, as set in the operating system,
 961      with standard language environment variables.  */
 962   locale = getenv ("LC_ALL");
 963   if (locale == NULL || locale[0] == '\0')
 964     {
 965       locale = getenv ("LC_CTYPE");
 966       if (locale == NULL || locale[0] == '\0')
 967         locale = getenv ("LANG");
 968     }
 969   if (locale != NULL && locale[0] != '\0')
 970     {
 971       /* If the locale name contains an encoding after the dot, return it.  */
 972       const char *dot = strchr (locale, '.');
 973
 974       if (dot != NULL)
 975         {
 976           const char *modifier;
 977
 978           dot++;
 979           /* Look for the possible @... trailer and remove it, if any.  */
 980           modifier = strchr (dot, '@');
 981           if (modifier == NULL)
 982             return dot;
 983           if (modifier - dot < sizeof (resultbuf))
 984             {
 985               /* This way of filling resultbuf is multithread-safe.  */
 986               memcpy (resultbuf, dot, modifier - dot);
 987               resultbuf [modifier - dot] = '\0';
 988               return resultbuf;
 989             }
 990         }
 991
 992       /* For the POSIX locale, don't use the system's codepage.  */
 993       if (strcmp (locale, "C") == 0 || strcmp (locale, "POSIX") == 0)
 994         codeset = "";
 995     }
 996
 997   if (codeset == NULL)
 998     {
 999       /* OS/2 has a function returning the locale's codepage as a number.  */
1000       if (DosQueryCp (sizeof (cp), cp, &cplen))
1001         codeset = "";
1002       else
1003         {
1004           char buf[2 + 10 + 1];
1005
1006           sprintf (buf, "CP%u", cp[0]);
1007           strcpy (resultbuf, buf);
1008           codeset = resultbuf;
1009         }
1010     }
1011
1012 # else
1013
1014 #  error "Add code for other platforms here."
1015
1016 # endif
1017
1018   /* Resolve alias.  */
1019   {
1020 # ifdef alias_table_defined
1021     /* On some platforms, UTF-8 locales are the most frequently used ones.
1022        Speed up the common case and slow down the less common cases by
1023        testing for this case first.  */
1024 #  if defined __OpenBSD__ || (defined __APPLE__ && defined __MACH__) || defined __sun || defined __CYGWIN__
1025     if (strcmp (codeset, "UTF-8") == 0)
1026       goto done_table_lookup;
1027     else
1028 #  endif
1029       {
1030         const struct table_entry * const table = alias_table;
1031         size_t const table_size =
1032           sizeof (alias_table) / sizeof (struct table_entry);
1033         /* The table is sorted.  Perform a binary search.  */
1034         size_t hi = table_size;
1035         size_t lo = 0;
1036         while (lo < hi)
1037           {
1038             /* Invariant:
1039                for i < lo, strcmp (table[i].alias, codeset) < 0,
1040                for i >= hi, strcmp (table[i].alias, codeset) > 0.  */
1041             size_t mid = (hi + lo) >> 1; /* >= lo, < hi */
1042             int cmp = strcmp (table[mid].alias, codeset);
1043             if (cmp < 0)
1044               lo = mid + 1;
1045             else if (cmp > 0)
1046               hi = mid;
1047             else
1048               {
1049                 /* Found an i with
1050                      strcmp (table[i].alias, codeset) == 0.  */
1051                 codeset = table[mid].canonical;
1052                 goto done_table_lookup;
1053               }
1054           }
1055       }
1056     if (0)
1057       done_table_lookup: {}
1058     else
1059 # endif
1060       {
1061         /* Did not find it in the table.  */
1062         /* On Mac OS X, all modern locales use the UTF-8 encoding.
1063            BeOS and Haiku have a single locale, and it has UTF-8 encoding.  */
1064 # if (defined __APPLE__ && defined __MACH__) || defined __BEOS__ || defined __HAIKU__
1065         codeset = "UTF-8";
1066 # else
1067         /* Don't return an empty string.  GNU libc and GNU libiconv interpret
1068            the empty string as denoting "the locale's character encoding",
1069            thus GNU libiconv would call this function a second time.  */
1070         if (codeset[0] == '\0')
1071           codeset = "ASCII";
1072 # endif
1073       }
1074   }
1075
1076 #else
1077
1078   /* On old systems which lack it, use setlocale or getenv.  */
1079   const char *locale = NULL;
1080
1081   /* But most old systems don't have a complete set of locales.  Some
1082      (like DJGPP) have only the C locale.  Therefore we don't use setlocale
1083      here; it would return "C" when it doesn't support the locale name the
1084      user has set.  */
1085 # if 0
1086   locale = setlocale (LC_CTYPE, NULL);
1087 # endif
1088   if (locale == NULL || locale[0] == '\0')
1089     {
1090       locale = getenv ("LC_ALL");
1091       if (locale == NULL || locale[0] == '\0')
1092         {
1093           locale = getenv ("LC_CTYPE");
1094           if (locale == NULL || locale[0] == '\0')
1095             locale = getenv ("LANG");
1096             if (locale == NULL)
1097               locale = "";
1098         }
1099     }
1100
1101   /* Map locale name to canonical encoding name.  */
1102   {
1103 # ifdef locale_table_defined
1104     const struct table_entry * const table = locale_table;
1105     size_t const table_size =
1106       sizeof (locale_table) / sizeof (struct table_entry);
1107     /* The table is sorted.  Perform a binary search.  */
1108     size_t hi = table_size;
1109     size_t lo = 0;
1110     while (lo < hi)
1111       {
1112         /* Invariant:
1113            for i < lo, strcmp (table[i].locale, locale) < 0,
1114            for i >= hi, strcmp (table[i].locale, locale) > 0.  */
1115         size_t mid = (hi + lo) >> 1; /* >= lo, < hi */
1116         int cmp = strcmp (table[mid].locale, locale);
1117         if (cmp < 0)
1118           lo = mid + 1;
1119         else if (cmp > 0)
1120           hi = mid;
1121         else
1122           {
1123             /* Found an i with
1124                  strcmp (table[i].locale, locale) == 0.  */
1125             codeset = table[mid].canonical;
1126             goto done_table_lookup;
1127           }
1128       }
1129     if (0)
1130       done_table_lookup: ;
1131     else
1132 # endif
1133       {
1134         /* Did not find it in the table.  */
1135         /* On Mac OS X, all modern locales use the UTF-8 encoding.
1136            BeOS and Haiku have a single locale, and it has UTF-8 encoding.  */
1137 # if (defined __APPLE__ && defined __MACH__) || defined __BEOS__ || defined __HAIKU__
1138         codeset = "UTF-8";
1139 # else
1140         /* The canonical name cannot be determined.  */
1141         /* Don't return an empty string.  GNU libc and GNU libiconv interpret
1142            the empty string as denoting "the locale's character encoding",
1143            thus GNU libiconv would call this function a second time.  */
1144         codeset = "ASCII";
1145 # endif
1146       }
1147   }
1148
1149 #endif
1150
1151 #ifdef DARWIN7
1152   /* Mac OS X sets MB_CUR_MAX to 1 when LC_ALL=C, and "UTF-8"
1153      (the default codeset) does not work when MB_CUR_MAX is 1.  */
1154   if (strcmp (codeset, "UTF-8") == 0 && MB_CUR_MAX_L (uselocale (NULL)) <= 1)
1155     codeset = "ASCII";
1156 #endif
1157
1158   return codeset;
1159 }