1 /* Determine a canonical name for the current locale's character encoding.
3 Copyright (C) 2000-2006 Free Software Foundation, Inc.
5 This program is free software; you can redistribute it and/or modify it
6 under the terms of the GNU Library General Public License as published
7 by the Free Software Foundation; either version 2, or (at your option)
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 GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with this program; if not, write to the Free Software
17 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
20 /* Written by Bruno Haible <bruno@clisp.org>. */
25 #include "localcharset.h"
32 #if defined _WIN32 || defined __WIN32__
37 /* Assume EMX program runs on OS/2, even if compiled under DOS. */
41 #if !defined WIN32_NATIVE
42 # if HAVE_LANGINFO_CODESET
43 # include <langinfo.h>
45 # if 0 /* see comment below */
50 # define WIN32_LEAN_AND_MEAN
53 #elif defined WIN32_NATIVE
54 # define WIN32_LEAN_AND_MEAN
62 #if ENABLE_RELOCATABLE
63 # include "relocatable.h"
65 # define relocate(pathname) (pathname)
68 /* Get GLIB_CHARSETALIAS_DIR. */
69 #ifndef GLIB_CHARSETALIAS_DIR
70 # define GLIB_CHARSETALIAS_DIR LIBDIR
73 #if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__
74 /* Win32, Cygwin, OS/2, DOS */
75 # define ISSLASH(C) ((C) == '/' || (C) == '\\')
78 #ifndef DIRECTORY_SEPARATOR
79 # define DIRECTORY_SEPARATOR '/'
83 # define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR)
86 #if HAVE_DECL_GETC_UNLOCKED
88 # define getc getc_unlocked
91 /* The following static variable is declared 'volatile' to avoid a
92 possible multithread problem in the function get_charset_aliases. If we
93 are running in a threaded environment, and if two threads initialize
94 'charset_aliases' simultaneously, both will produce the same value,
95 and everything will be ok if the two assignments to 'charset_aliases'
96 are atomic. But I don't know what will happen if the two assignments mix. */
98 # define volatile /* empty */
100 /* Pointer to the contents of the charset.alias file, if it has already been
101 read, else NULL. Its format is:
102 ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0' */
103 static const char * volatile charset_aliases;
105 /* Return a pointer to the contents of the charset.alias file. */
107 _g_locale_get_charset_aliases (void)
111 cp = charset_aliases;
114 #if !(defined VMS || defined WIN32_NATIVE || defined __CYGWIN__)
117 const char *base = "charset.alias";
120 dir = relocate (GLIB_CHARSETALIAS_DIR);
122 /* Concatenate dir and base into freshly allocated file_name. */
124 size_t dir_len = strlen (dir);
125 size_t base_len = strlen (base);
126 int add_slash = (dir_len > 0 && !ISSLASH (dir[dir_len - 1]));
127 file_name = (char *) malloc (dir_len + add_slash + base_len + 1);
128 if (file_name != NULL)
130 memcpy (file_name, dir, dir_len);
132 file_name[dir_len] = DIRECTORY_SEPARATOR;
133 memcpy (file_name + dir_len + add_slash, base, base_len + 1);
137 if (file_name == NULL || (fp = fopen (file_name, "r")) == NULL)
138 /* Out of memory or file not found, treat it as empty. */
142 /* Parse the file's contents. */
143 char *res_ptr = NULL;
157 if (c == '\n' || c == ' ' || c == '\t')
161 /* Skip comment, to end of line. */
164 while (!(c == EOF || c == '\n'));
170 if (fscanf (fp, "%50s %50s", buf1, buf2) < 2)
174 old_res_ptr = res_ptr;
177 res_size = l1 + 1 + l2 + 1;
178 res_ptr = (char *) malloc (res_size + 1);
182 res_size += l1 + 1 + l2 + 1;
183 res_ptr = (char *) realloc (res_ptr, res_size + 1);
189 if (old_res_ptr != NULL)
193 strcpy (res_ptr + res_size - (l2 + 1) - (l1 + 1), buf1);
194 strcpy (res_ptr + res_size - (l2 + 1), buf2);
201 *(res_ptr + res_size) = '\0';
206 if (file_name != NULL)
212 /* To avoid the troubles of an extra file charset.alias_vms in the
213 sources of many GNU packages, simply inline the aliases here. */
214 /* The list of encodings is taken from the OpenVMS 7.3-1 documentation
215 "Compaq C Run-Time Library Reference Manual for OpenVMS systems"
216 section 10.7 "Handling Different Character Sets". */
217 cp = "ISO8859-1" "\0" "ISO-8859-1" "\0"
218 "ISO8859-2" "\0" "ISO-8859-2" "\0"
219 "ISO8859-5" "\0" "ISO-8859-5" "\0"
220 "ISO8859-7" "\0" "ISO-8859-7" "\0"
221 "ISO8859-8" "\0" "ISO-8859-8" "\0"
222 "ISO8859-9" "\0" "ISO-8859-9" "\0"
224 "eucJP" "\0" "EUC-JP" "\0"
225 "SJIS" "\0" "SHIFT_JIS" "\0"
226 "DECKANJI" "\0" "DEC-KANJI" "\0"
227 "SDECKANJI" "\0" "EUC-JP" "\0"
229 "eucTW" "\0" "EUC-TW" "\0"
230 "DECHANYU" "\0" "DEC-HANYU" "\0"
231 "DECHANZI" "\0" "GB2312" "\0"
233 "DECKOREAN" "\0" "EUC-KR" "\0";
236 # if defined WIN32_NATIVE || defined __CYGWIN__
237 /* To avoid the troubles of installing a separate file in the same
238 directory as the DLL and of retrieving the DLL's directory at
239 runtime, simply inline the aliases here. */
241 cp = "CP936" "\0" "GBK" "\0"
242 "CP1361" "\0" "JOHAB" "\0"
243 "CP20127" "\0" "ASCII" "\0"
244 "CP20866" "\0" "KOI8-R" "\0"
245 "CP20936" "\0" "GB2312" "\0"
246 "CP21866" "\0" "KOI8-RU" "\0"
247 "CP28591" "\0" "ISO-8859-1" "\0"
248 "CP28592" "\0" "ISO-8859-2" "\0"
249 "CP28593" "\0" "ISO-8859-3" "\0"
250 "CP28594" "\0" "ISO-8859-4" "\0"
251 "CP28595" "\0" "ISO-8859-5" "\0"
252 "CP28596" "\0" "ISO-8859-6" "\0"
253 "CP28597" "\0" "ISO-8859-7" "\0"
254 "CP28598" "\0" "ISO-8859-8" "\0"
255 "CP28599" "\0" "ISO-8859-9" "\0"
256 "CP28605" "\0" "ISO-8859-15" "\0"
257 "CP38598" "\0" "ISO-8859-8" "\0"
258 "CP51932" "\0" "EUC-JP" "\0"
259 "CP51936" "\0" "GB2312" "\0"
260 "CP51949" "\0" "EUC-KR" "\0"
261 "CP51950" "\0" "EUC-TW" "\0"
262 "CP54936" "\0" "GB18030" "\0"
263 "CP65001" "\0" "UTF-8" "\0";
267 charset_aliases = cp;
273 /* Determine the current locale's character encoding, and canonicalize it
274 into one of the canonical names listed in config.charset.
275 The result must not be freed; it is statically allocated.
276 If the canonical name cannot be determined, the result is a non-canonical
280 _g_locale_charset_raw (void)
284 #if !(defined WIN32_NATIVE || defined OS2)
286 # if HAVE_LANGINFO_CODESET
288 /* Most systems support nl_langinfo (CODESET) nowadays. */
289 codeset = nl_langinfo (CODESET);
292 /* Cygwin 2006 does not have locales. nl_langinfo (CODESET) always
293 returns "US-ASCII". As long as this is not fixed, return the suffix
294 of the locale name from the environment variables (if present) or
295 the codepage as a number. */
296 if (codeset != NULL && strcmp (codeset, "US-ASCII") == 0)
299 static char buf[2 + 10 + 1];
301 locale = getenv ("LC_ALL");
302 if (locale == NULL || locale[0] == '\0')
304 locale = getenv ("LC_CTYPE");
305 if (locale == NULL || locale[0] == '\0')
306 locale = getenv ("LANG");
308 if (locale != NULL && locale[0] != '\0')
310 /* If the locale name contains an encoding after the dot, return
312 const char *dot = strchr (locale, '.');
316 const char *modifier;
319 /* Look for the possible @... trailer and remove it, if any. */
320 modifier = strchr (dot, '@');
321 if (modifier == NULL)
323 if (modifier - dot < sizeof (buf))
325 memcpy (buf, dot, modifier - dot);
326 buf [modifier - dot] = '\0';
332 /* Woe32 has a function returning the locale's codepage as a number. */
333 sprintf (buf, "CP%u", GetACP ());
340 /* On old systems which lack it, use setlocale or getenv. */
341 const char *locale = NULL;
343 /* But most old systems don't have a complete set of locales. Some
344 (like SunOS 4 or DJGPP) have only the C locale. Therefore we don't
345 use setlocale here; it would return "C" when it doesn't support the
346 locale name the user has set. */
348 locale = setlocale (LC_CTYPE, NULL);
350 if (locale == NULL || locale[0] == '\0')
352 locale = getenv ("LC_ALL");
353 if (locale == NULL || locale[0] == '\0')
355 locale = getenv ("LC_CTYPE");
356 if (locale == NULL || locale[0] == '\0')
357 locale = getenv ("LANG");
361 /* On some old systems, one used to set locale = "iso8859_1". On others,
362 you set it to "language_COUNTRY.charset". In any case, we resolve it
363 through the charset.alias file. */
368 #elif defined WIN32_NATIVE
370 static char buf[2 + 10 + 1];
372 /* Woe32 has a function returning the locale's codepage as a number. */
373 sprintf (buf, "CP%u", GetACP ());
379 static char buf[2 + 10 + 1];
383 /* Allow user to override the codeset, as set in the operating system,
384 with standard language environment variables. */
385 locale = getenv ("LC_ALL");
386 if (locale == NULL || locale[0] == '\0')
388 locale = getenv ("LC_CTYPE");
389 if (locale == NULL || locale[0] == '\0')
390 locale = getenv ("LANG");
392 if (locale != NULL && locale[0] != '\0')
394 /* If the locale name contains an encoding after the dot, return it. */
395 const char *dot = strchr (locale, '.');
399 const char *modifier;
402 /* Look for the possible @... trailer and remove it, if any. */
403 modifier = strchr (dot, '@');
404 if (modifier == NULL)
406 if (modifier - dot < sizeof (buf))
408 memcpy (buf, dot, modifier - dot);
409 buf [modifier - dot] = '\0';
414 /* Resolve through the charset.alias file. */
419 /* OS/2 has a function returning the locale's codepage as a number. */
420 if (DosQueryCp (sizeof (cp), cp, &cplen))
424 sprintf (buf, "CP%u", cp[0]);
435 _g_locale_charset_unalias (const char *codeset)
440 /* The canonical name cannot be determined. */
444 for (aliases = _g_locale_get_charset_aliases ();
446 aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1)
447 if (strcmp (codeset, aliases) == 0
448 || (aliases[0] == '*' && aliases[1] == '\0'))
450 codeset = aliases + strlen (aliases) + 1;
454 /* Don't return an empty string. GNU libc and GNU libiconv interpret
455 the empty string as denoting "the locale's character encoding",
456 thus GNU libiconv would call this function a second time. */
457 if (codeset[0] == '\0')