1 /* Determine a canonical name for the current locale's character encoding.
3 Copyright (C) 2000-2002 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
20 /* Written by Bruno Haible <bruno@clisp.org>. */
40 #if defined _WIN32 || defined __WIN32__
41 # undef WIN32 /* avoid warning on mingw32 */
46 /* Assume EMX program runs on OS/2, even if compiled under DOS. */
51 # if HAVE_LANGINFO_CODESET
52 # include <langinfo.h>
59 # define WIN32_LEAN_AND_MEAN
67 #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__
68 /* Win32, OS/2, DOS */
69 # define ISSLASH(C) ((C) == '/' || (C) == '\\')
72 #ifndef DIRECTORY_SEPARATOR
73 # define DIRECTORY_SEPARATOR '/'
77 # define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR)
80 #ifdef HAVE_GETC_UNLOCKED
82 # define getc getc_unlocked
86 /* When compiling with "gcc -x c++", produce a function with C linkage. */
87 extern "C" const char * locale_charset (void);
90 /* The following static variable is declared 'volatile' to avoid a
91 possible multithread problem in the function get_charset_aliases. If we
92 are running in a threaded environment, and if two threads initialize
93 'charset_aliases' simultaneously, both will produce the same value,
94 and everything will be ok if the two assignments to 'charset_aliases'
95 are atomic. But I don't know what will happen if the two assignments mix. */
97 # define volatile /* empty */
99 /* Pointer to the contents of the charset.alias file, if it has already been
100 read, else NULL. Its format is:
101 ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0' */
102 static const char * volatile charset_aliases
;
104 /* Return a pointer to the contents of the charset.alias file. */
106 _gsasl_locale_get_charset_aliases ()
110 cp
= charset_aliases
;
115 const char *dir
= LIBDIR
;
116 const char *base
= "charset.alias";
119 /* Concatenate dir and base into freshly allocated file_name. */
121 size_t dir_len
= strlen (dir
);
122 size_t base_len
= strlen (base
);
123 int add_slash
= (dir_len
> 0 && !ISSLASH (dir
[dir_len
- 1]));
124 file_name
= (char *) malloc (dir_len
+ add_slash
+ base_len
+ 1);
125 if (file_name
!= NULL
)
127 memcpy (file_name
, dir
, dir_len
);
129 file_name
[dir_len
] = DIRECTORY_SEPARATOR
;
130 memcpy (file_name
+ dir_len
+ add_slash
, base
, base_len
+ 1);
134 if (file_name
== NULL
|| (fp
= fopen (file_name
, "r")) == NULL
)
135 /* Out of memory or file not found, treat it as empty. */
139 /* Parse the file's contents. */
143 char *res_ptr
= NULL
;
152 if (c
== '\n' || c
== ' ' || c
== '\t')
156 /* Skip comment, to end of line. */
159 while (!(c
== EOF
|| c
== '\n'));
165 if (fscanf (fp
, "%50s %50s", buf1
, buf2
) < 2)
171 res_size
= l1
+ 1 + l2
+ 1;
172 res_ptr
= (char *) malloc (res_size
+ 1);
176 res_size
+= l1
+ 1 + l2
+ 1;
177 res_ptr
= (char *) realloc (res_ptr
, res_size
+ 1);
185 strcpy (res_ptr
+ res_size
- (l2
+ 1) - (l1
+ 1), buf1
);
186 strcpy (res_ptr
+ res_size
- (l2
+ 1), buf2
);
193 *(res_ptr
+ res_size
) = '\0';
198 if (file_name
!= NULL
)
203 /* To avoid the troubles of installing a separate file in the same
204 directory as the DLL and of retrieving the DLL's directory at
205 runtime, simply inline the aliases here. */
208 cp
= "CP936" "\0" "GBK" "\0"
209 "CP1361" "\0" "JOHAB" "\0"
210 "CP20127" "\0" "ASCII" "\0"
211 "CP20866" "\0" "KOI8-R" "\0"
212 "CP21866" "\0" "KOI8-RU" "\0"
213 "CP28591" "\0" "ISO-8859-1" "\0"
214 "CP28592" "\0" "ISO-8859-2" "\0"
215 "CP28593" "\0" "ISO-8859-3" "\0"
216 "CP28594" "\0" "ISO-8859-4" "\0"
217 "CP28595" "\0" "ISO-8859-5" "\0"
218 "CP28596" "\0" "ISO-8859-6" "\0"
219 "CP28597" "\0" "ISO-8859-7" "\0"
220 "CP28598" "\0" "ISO-8859-8" "\0"
221 "CP28599" "\0" "ISO-8859-9" "\0"
222 "CP28605" "\0" "ISO-8859-15" "\0";
226 charset_aliases
= cp
;
232 /* Determine the current locale's character encoding, and canonicalize it
233 into one of the canonical names listed in config.charset.
234 The result must not be freed; it is statically allocated.
235 If the canonical name cannot be determined, the result is a non-canonical
242 _gsasl_locale_charset ()
247 #if !(defined WIN32 || defined OS2)
249 # if HAVE_LANGINFO_CODESET
251 /* Most systems support nl_langinfo (CODESET) nowadays. */
252 codeset
= nl_langinfo (CODESET
);
256 /* On old systems which lack it, use setlocale or getenv. */
257 const char *locale
= NULL
;
259 /* But most old systems don't have a complete set of locales. Some
260 (like SunOS 4 or DJGPP) have only the C locale. Therefore we don't
261 use setlocale here; it would return "C" when it doesn't support the
262 locale name the user has set. */
263 # if HAVE_SETLOCALE && 0
264 locale
= setlocale (LC_CTYPE
, NULL
);
266 if (locale
== NULL
|| locale
[0] == '\0')
268 locale
= getenv ("LC_ALL");
269 if (locale
== NULL
|| locale
[0] == '\0')
271 locale
= getenv ("LC_CTYPE");
272 if (locale
== NULL
|| locale
[0] == '\0')
273 locale
= getenv ("LANG");
277 /* On some old systems, one used to set locale = "iso8859_1". On others,
278 you set it to "language_COUNTRY.charset". In any case, we resolve it
279 through the charset.alias file. */
286 static char buf
[2 + 10 + 1];
288 /* Woe32 has a function returning the locale's codepage as a number. */
289 sprintf (buf
, "CP%u", GetACP ());
295 static char buf
[2 + 10 + 1];
299 /* Allow user to override the codeset, as set in the operating system,
300 with standard language environment variables. */
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 it. */
311 const char *dot
= strchr (locale
, '.');
315 const char *modifier
;
318 /* Look for the possible @... trailer and remove it, if any. */
319 modifier
= strchr (dot
, '@');
320 if (modifier
== NULL
)
322 if (modifier
- dot
< sizeof (buf
))
324 memcpy (buf
, dot
, modifier
- dot
);
325 buf
[modifier
- dot
] = '\0';
330 /* Resolve through the charset.alias file. */
335 /* OS/2 has a function returning the locale's codepage as a number. */
336 if (DosQueryCp (sizeof (cp
), cp
, &cplen
))
340 sprintf (buf
, "CP%u", cp
[0]);
348 /* The canonical name cannot be determined. */
352 for (aliases
= _gsasl_locale_get_charset_aliases ();
354 aliases
+= strlen (aliases
) + 1, aliases
+= strlen (aliases
) + 1)
355 if (strcmp (codeset
, aliases
) == 0
356 || (aliases
[0] == '*' && aliases
[1] == '\0'))
358 codeset
= aliases
+ strlen (aliases
) + 1;
362 /* Don't return an empty string. GNU libc and GNU libiconv interpret
363 the empty string as denoting "the locale's character encoding",
364 thus GNU libiconv would call this function a second time. */
365 if (codeset
[0] == '\0')