1 /* Determine a canonical name for the current locale's character encoding.
3 Copyright (C) 2000-2003 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>. */
27 #include "localcharset.h"
43 #if defined _WIN32 || defined __WIN32__
44 # undef WIN32 /* avoid warning on mingw32 */
49 /* Assume EMX program runs on OS/2, even if compiled under DOS. */
54 # if HAVE_LANGINFO_CODESET
55 # include <langinfo.h>
62 # define WIN32_LEAN_AND_MEAN
70 #if ENABLE_RELOCATABLE
71 # include "relocatable.h"
73 # define relocate(pathname) (pathname)
76 #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__
77 /* Win32, OS/2, DOS */
78 # define ISSLASH(C) ((C) == '/' || (C) == '\\')
81 #ifndef DIRECTORY_SEPARATOR
82 # define DIRECTORY_SEPARATOR '/'
86 # define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR)
89 #ifdef HAVE_GETC_UNLOCKED
91 # define getc getc_unlocked
94 /* The following static variable is declared 'volatile' to avoid a
95 possible multithread problem in the function get_charset_aliases. If we
96 are running in a threaded environment, and if two threads initialize
97 'charset_aliases' simultaneously, both will produce the same value,
98 and everything will be ok if the two assignments to 'charset_aliases'
99 are atomic. But I don't know what will happen if the two assignments mix. */
101 # define volatile /* empty */
103 /* Pointer to the contents of the charset.alias file, if it has already been
104 read, else NULL. Its format is:
105 ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0' */
106 static const char * volatile charset_aliases
;
108 /* Return a pointer to the contents of the charset.alias file. */
110 get_charset_aliases ()
114 cp
= charset_aliases
;
117 #if !(defined VMS || defined WIN32)
119 const char *dir
= relocate (LIBDIR
);
120 const char *base
= "charset.alias";
123 /* Concatenate dir and base into freshly allocated file_name. */
125 size_t dir_len
= strlen (dir
);
126 size_t base_len
= strlen (base
);
127 int add_slash
= (dir_len
> 0 && !ISSLASH (dir
[dir_len
- 1]));
128 file_name
= (char *) malloc (dir_len
+ add_slash
+ base_len
+ 1);
129 if (file_name
!= NULL
)
131 memcpy (file_name
, dir
, dir_len
);
133 file_name
[dir_len
] = DIRECTORY_SEPARATOR
;
134 memcpy (file_name
+ dir_len
+ add_slash
, base
, base_len
+ 1);
138 if (file_name
== NULL
|| (fp
= fopen (file_name
, "r")) == NULL
)
139 /* Out of memory or file not found, treat it as empty. */
143 /* Parse the file's contents. */
147 char *res_ptr
= NULL
;
156 if (c
== '\n' || c
== ' ' || c
== '\t')
160 /* Skip comment, to end of line. */
163 while (!(c
== EOF
|| c
== '\n'));
169 if (fscanf (fp
, "%50s %50s", buf1
, buf2
) < 2)
175 res_size
= l1
+ 1 + l2
+ 1;
176 res_ptr
= (char *) malloc (res_size
+ 1);
180 res_size
+= l1
+ 1 + l2
+ 1;
181 res_ptr
= (char *) realloc (res_ptr
, res_size
+ 1);
189 strcpy (res_ptr
+ res_size
- (l2
+ 1) - (l1
+ 1), buf1
);
190 strcpy (res_ptr
+ res_size
- (l2
+ 1), buf2
);
197 *(res_ptr
+ res_size
) = '\0';
202 if (file_name
!= NULL
)
208 /* To avoid the troubles of an extra file charset.alias_vms in the
209 sources of many GNU packages, simply inline the aliases here. */
210 /* The list of encodings is taken from the OpenVMS 7.3-1 documentation
211 "Compaq C Run-Time Library Reference Manual for OpenVMS systems"
212 section 10.7 "Handling Different Character Sets". */
213 cp
= "ISO8859-1" "\0" "ISO-8859-1" "\0"
214 "ISO8859-2" "\0" "ISO-8859-2" "\0"
215 "ISO8859-5" "\0" "ISO-8859-5" "\0"
216 "ISO8859-7" "\0" "ISO-8859-7" "\0"
217 "ISO8859-8" "\0" "ISO-8859-8" "\0"
218 "ISO8859-9" "\0" "ISO-8859-9" "\0"
220 "eucJP" "\0" "EUC-JP" "\0"
221 "SJIS" "\0" "SHIFT_JIS" "\0"
222 "DECKANJI" "\0" "DEC-KANJI" "\0"
223 "SDECKANJI" "\0" "EUC-JP" "\0"
225 "eucTW" "\0" "EUC-TW" "\0"
226 "DECHANYU" "\0" "DEC-HANYU" "\0"
227 "DECHANZI" "\0" "GB2312" "\0"
229 "DECKOREAN" "\0" "EUC-KR" "\0";
233 /* To avoid the troubles of installing a separate file in the same
234 directory as the DLL and of retrieving the DLL's directory at
235 runtime, simply inline the aliases here. */
237 cp
= "CP936" "\0" "GBK" "\0"
238 "CP1361" "\0" "JOHAB" "\0"
239 "CP20127" "\0" "ASCII" "\0"
240 "CP20866" "\0" "KOI8-R" "\0"
241 "CP21866" "\0" "KOI8-RU" "\0"
242 "CP28591" "\0" "ISO-8859-1" "\0"
243 "CP28592" "\0" "ISO-8859-2" "\0"
244 "CP28593" "\0" "ISO-8859-3" "\0"
245 "CP28594" "\0" "ISO-8859-4" "\0"
246 "CP28595" "\0" "ISO-8859-5" "\0"
247 "CP28596" "\0" "ISO-8859-6" "\0"
248 "CP28597" "\0" "ISO-8859-7" "\0"
249 "CP28598" "\0" "ISO-8859-8" "\0"
250 "CP28599" "\0" "ISO-8859-9" "\0"
251 "CP28605" "\0" "ISO-8859-15" "\0";
255 charset_aliases
= cp
;
261 /* Determine the current locale's character encoding, and canonicalize it
262 into one of the canonical names listed in config.charset.
263 The result must not be freed; it is statically allocated.
264 If the canonical name cannot be determined, the result is a non-canonical
276 #if !(defined WIN32 || defined OS2)
278 # if HAVE_LANGINFO_CODESET
280 /* Most systems support nl_langinfo (CODESET) nowadays. */
281 codeset
= nl_langinfo (CODESET
);
285 /* On old systems which lack it, use setlocale or getenv. */
286 const char *locale
= NULL
;
288 /* But most old systems don't have a complete set of locales. Some
289 (like SunOS 4 or DJGPP) have only the C locale. Therefore we don't
290 use setlocale here; it would return "C" when it doesn't support the
291 locale name the user has set. */
292 # if HAVE_SETLOCALE && 0
293 locale
= setlocale (LC_CTYPE
, NULL
);
295 if (locale
== NULL
|| locale
[0] == '\0')
297 locale
= getenv ("LC_ALL");
298 if (locale
== NULL
|| locale
[0] == '\0')
300 locale
= getenv ("LC_CTYPE");
301 if (locale
== NULL
|| locale
[0] == '\0')
302 locale
= getenv ("LANG");
306 /* On some old systems, one used to set locale = "iso8859_1". On others,
307 you set it to "language_COUNTRY.charset". In any case, we resolve it
308 through the charset.alias file. */
315 static char buf
[2 + 10 + 1];
317 /* Woe32 has a function returning the locale's codepage as a number. */
318 sprintf (buf
, "CP%u", GetACP ());
324 static char buf
[2 + 10 + 1];
328 /* Allow user to override the codeset, as set in the operating system,
329 with standard language environment variables. */
330 locale
= getenv ("LC_ALL");
331 if (locale
== NULL
|| locale
[0] == '\0')
333 locale
= getenv ("LC_CTYPE");
334 if (locale
== NULL
|| locale
[0] == '\0')
335 locale
= getenv ("LANG");
337 if (locale
!= NULL
&& locale
[0] != '\0')
339 /* If the locale name contains an encoding after the dot, return it. */
340 const char *dot
= strchr (locale
, '.');
344 const char *modifier
;
347 /* Look for the possible @... trailer and remove it, if any. */
348 modifier
= strchr (dot
, '@');
349 if (modifier
== NULL
)
351 if (modifier
- dot
< sizeof (buf
))
353 memcpy (buf
, dot
, modifier
- dot
);
354 buf
[modifier
- dot
] = '\0';
359 /* Resolve through the charset.alias file. */
364 /* OS/2 has a function returning the locale's codepage as a number. */
365 if (DosQueryCp (sizeof (cp
), cp
, &cplen
))
369 sprintf (buf
, "CP%u", cp
[0]);
377 /* The canonical name cannot be determined. */
381 for (aliases
= get_charset_aliases ();
383 aliases
+= strlen (aliases
) + 1, aliases
+= strlen (aliases
) + 1)
384 if (strcmp (codeset
, aliases
) == 0
385 || (aliases
[0] == '*' && aliases
[1] == '\0'))
387 codeset
= aliases
+ strlen (aliases
) + 1;
391 /* Don't return an empty string. GNU libc and GNU libiconv interpret
392 the empty string as denoting "the locale's character encoding",
393 thus GNU libiconv would call this function a second time. */
394 if (codeset
[0] == '\0')
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