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-rw-r--r--intl/localcharset.c398
1 files changed, 398 insertions, 0 deletions
diff --git a/intl/localcharset.c b/intl/localcharset.c
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--- /dev/null
+++ b/intl/localcharset.c
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+/* Determine a canonical name for the current locale's character encoding.
+
+ Copyright (C) 2000-2003 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Library General Public License as published
+ by the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ USA. */
+
+/* Written by Bruno Haible <bruno@clisp.org>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+/* Specification. */
+#include "localcharset.h"
+
+#if HAVE_STDDEF_H
+# include <stddef.h>
+#endif
+
+#include <stdio.h>
+#if HAVE_STRING_H
+# include <string.h>
+#else
+# include <strings.h>
+#endif
+#if HAVE_STDLIB_H
+# include <stdlib.h>
+#endif
+
+#if defined _WIN32 || defined __WIN32__
+# undef WIN32 /* avoid warning on mingw32 */
+# define WIN32
+#endif
+
+#if defined __EMX__
+/* Assume EMX program runs on OS/2, even if compiled under DOS. */
+# define OS2
+#endif
+
+#if !defined WIN32
+# if HAVE_LANGINFO_CODESET
+# include <langinfo.h>
+# else
+# if HAVE_SETLOCALE
+# include <locale.h>
+# endif
+# endif
+#elif defined WIN32
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+#if defined OS2
+# define INCL_DOS
+# include <os2.h>
+#endif
+
+#if ENABLE_RELOCATABLE
+# include "relocatable.h"
+#else
+# define relocate(pathname) (pathname)
+#endif
+
+#if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__
+ /* Win32, OS/2, DOS */
+# define ISSLASH(C) ((C) == '/' || (C) == '\\')
+#endif
+
+#ifndef DIRECTORY_SEPARATOR
+# define DIRECTORY_SEPARATOR '/'
+#endif
+
+#ifndef ISSLASH
+# define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR)
+#endif
+
+#ifdef HAVE_GETC_UNLOCKED
+# undef getc
+# define getc getc_unlocked
+#endif
+
+/* The following static variable is declared 'volatile' to avoid a
+ possible multithread problem in the function get_charset_aliases. If we
+ are running in a threaded environment, and if two threads initialize
+ 'charset_aliases' simultaneously, both will produce the same value,
+ and everything will be ok if the two assignments to 'charset_aliases'
+ are atomic. But I don't know what will happen if the two assignments mix. */
+#if __STDC__ != 1
+# define volatile /* empty */
+#endif
+/* Pointer to the contents of the charset.alias file, if it has already been
+ read, else NULL. Its format is:
+ ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0' */
+static const char * volatile charset_aliases;
+
+/* Return a pointer to the contents of the charset.alias file. */
+static const char *
+get_charset_aliases ()
+{
+ const char *cp;
+
+ cp = charset_aliases;
+ if (cp == NULL)
+ {
+#if !(defined VMS || defined WIN32)
+ FILE *fp;
+ const char *dir = relocate (LIBDIR);
+ const char *base = "charset.alias";
+ char *file_name;
+
+ /* Concatenate dir and base into freshly allocated file_name. */
+ {
+ size_t dir_len = strlen (dir);
+ size_t base_len = strlen (base);
+ int add_slash = (dir_len > 0 && !ISSLASH (dir[dir_len - 1]));
+ file_name = (char *) malloc (dir_len + add_slash + base_len + 1);
+ if (file_name != NULL)
+ {
+ memcpy (file_name, dir, dir_len);
+ if (add_slash)
+ file_name[dir_len] = DIRECTORY_SEPARATOR;
+ memcpy (file_name + dir_len + add_slash, base, base_len + 1);
+ }
+ }
+
+ if (file_name == NULL || (fp = fopen (file_name, "r")) == NULL)
+ /* Out of memory or file not found, treat it as empty. */
+ cp = "";
+ else
+ {
+ /* Parse the file's contents. */
+ int c;
+ char buf1[50+1];
+ char buf2[50+1];
+ char *res_ptr = NULL;
+ size_t res_size = 0;
+ size_t l1, l2;
+
+ for (;;)
+ {
+ c = getc (fp);
+ if (c == EOF)
+ break;
+ if (c == '\n' || c == ' ' || c == '\t')
+ continue;
+ if (c == '#')
+ {
+ /* Skip comment, to end of line. */
+ do
+ c = getc (fp);
+ while (!(c == EOF || c == '\n'));
+ if (c == EOF)
+ break;
+ continue;
+ }
+ ungetc (c, fp);
+ if (fscanf (fp, "%50s %50s", buf1, buf2) < 2)
+ break;
+ l1 = strlen (buf1);
+ l2 = strlen (buf2);
+ if (res_size == 0)
+ {
+ res_size = l1 + 1 + l2 + 1;
+ res_ptr = (char *) malloc (res_size + 1);
+ }
+ else
+ {
+ res_size += l1 + 1 + l2 + 1;
+ res_ptr = (char *) realloc (res_ptr, res_size + 1);
+ }
+ if (res_ptr == NULL)
+ {
+ /* Out of memory. */
+ res_size = 0;
+ break;
+ }
+ strcpy (res_ptr + res_size - (l2 + 1) - (l1 + 1), buf1);
+ strcpy (res_ptr + res_size - (l2 + 1), buf2);
+ }
+ fclose (fp);
+ if (res_size == 0)
+ cp = "";
+ else
+ {
+ *(res_ptr + res_size) = '\0';
+ cp = res_ptr;
+ }
+ }
+
+ if (file_name != NULL)
+ free (file_name);
+
+#else
+
+# if defined VMS
+ /* To avoid the troubles of an extra file charset.alias_vms in the
+ sources of many GNU packages, simply inline the aliases here. */
+ /* The list of encodings is taken from the OpenVMS 7.3-1 documentation
+ "Compaq C Run-Time Library Reference Manual for OpenVMS systems"
+ section 10.7 "Handling Different Character Sets". */
+ cp = "ISO8859-1" "\0" "ISO-8859-1" "\0"
+ "ISO8859-2" "\0" "ISO-8859-2" "\0"
+ "ISO8859-5" "\0" "ISO-8859-5" "\0"
+ "ISO8859-7" "\0" "ISO-8859-7" "\0"
+ "ISO8859-8" "\0" "ISO-8859-8" "\0"
+ "ISO8859-9" "\0" "ISO-8859-9" "\0"
+ /* Japanese */
+ "eucJP" "\0" "EUC-JP" "\0"
+ "SJIS" "\0" "SHIFT_JIS" "\0"
+ "DECKANJI" "\0" "DEC-KANJI" "\0"
+ "SDECKANJI" "\0" "EUC-JP" "\0"
+ /* Chinese */
+ "eucTW" "\0" "EUC-TW" "\0"
+ "DECHANYU" "\0" "DEC-HANYU" "\0"
+ "DECHANZI" "\0" "GB2312" "\0"
+ /* Korean */
+ "DECKOREAN" "\0" "EUC-KR" "\0";
+# endif
+
+# if defined WIN32
+ /* To avoid the troubles of installing a separate file in the same
+ directory as the DLL and of retrieving the DLL's directory at
+ runtime, simply inline the aliases here. */
+
+ cp = "CP936" "\0" "GBK" "\0"
+ "CP1361" "\0" "JOHAB" "\0"
+ "CP20127" "\0" "ASCII" "\0"
+ "CP20866" "\0" "KOI8-R" "\0"
+ "CP21866" "\0" "KOI8-RU" "\0"
+ "CP28591" "\0" "ISO-8859-1" "\0"
+ "CP28592" "\0" "ISO-8859-2" "\0"
+ "CP28593" "\0" "ISO-8859-3" "\0"
+ "CP28594" "\0" "ISO-8859-4" "\0"
+ "CP28595" "\0" "ISO-8859-5" "\0"
+ "CP28596" "\0" "ISO-8859-6" "\0"
+ "CP28597" "\0" "ISO-8859-7" "\0"
+ "CP28598" "\0" "ISO-8859-8" "\0"
+ "CP28599" "\0" "ISO-8859-9" "\0"
+ "CP28605" "\0" "ISO-8859-15" "\0";
+# endif
+#endif
+
+ charset_aliases = cp;
+ }
+
+ return cp;
+}
+
+/* Determine the current locale's character encoding, and canonicalize it
+ into one of the canonical names listed in config.charset.
+ The result must not be freed; it is statically allocated.
+ If the canonical name cannot be determined, the result is a non-canonical
+ name. */
+
+#ifdef STATIC
+STATIC
+#endif
+const char *
+locale_charset ()
+{
+ const char *codeset;
+ const char *aliases;
+
+#if !(defined WIN32 || defined OS2)
+
+# if HAVE_LANGINFO_CODESET
+
+ /* Most systems support nl_langinfo (CODESET) nowadays. */
+ codeset = nl_langinfo (CODESET);
+
+# else
+
+ /* On old systems which lack it, use setlocale or getenv. */
+ const char *locale = NULL;
+
+ /* But most old systems don't have a complete set of locales. Some
+ (like SunOS 4 or DJGPP) have only the C locale. Therefore we don't
+ use setlocale here; it would return "C" when it doesn't support the
+ locale name the user has set. */
+# if HAVE_SETLOCALE && 0
+ locale = setlocale (LC_CTYPE, NULL);
+# endif
+ if (locale == NULL || locale[0] == '\0')
+ {
+ locale = getenv ("LC_ALL");
+ if (locale == NULL || locale[0] == '\0')
+ {
+ locale = getenv ("LC_CTYPE");
+ if (locale == NULL || locale[0] == '\0')
+ locale = getenv ("LANG");
+ }
+ }
+
+ /* On some old systems, one used to set locale = "iso8859_1". On others,
+ you set it to "language_COUNTRY.charset". In any case, we resolve it
+ through the charset.alias file. */
+ codeset = locale;
+
+# endif
+
+#elif defined WIN32
+
+ static char buf[2 + 10 + 1];
+
+ /* Woe32 has a function returning the locale's codepage as a number. */
+ sprintf (buf, "CP%u", GetACP ());
+ codeset = buf;
+
+#elif defined OS2
+
+ const char *locale;
+ static char buf[2 + 10 + 1];
+ ULONG cp[3];
+ ULONG cplen;
+
+ /* Allow user to override the codeset, as set in the operating system,
+ with standard language environment variables. */
+ locale = getenv ("LC_ALL");
+ if (locale == NULL || locale[0] == '\0')
+ {
+ locale = getenv ("LC_CTYPE");
+ if (locale == NULL || locale[0] == '\0')
+ locale = getenv ("LANG");
+ }
+ if (locale != NULL && locale[0] != '\0')
+ {
+ /* If the locale name contains an encoding after the dot, return it. */
+ const char *dot = strchr (locale, '.');
+
+ if (dot != NULL)
+ {
+ const char *modifier;
+
+ dot++;
+ /* Look for the possible @... trailer and remove it, if any. */
+ modifier = strchr (dot, '@');
+ if (modifier == NULL)
+ return dot;
+ if (modifier - dot < sizeof (buf))
+ {
+ memcpy (buf, dot, modifier - dot);
+ buf [modifier - dot] = '\0';
+ return buf;
+ }
+ }
+
+ /* Resolve through the charset.alias file. */
+ codeset = locale;
+ }
+ else
+ {
+ /* OS/2 has a function returning the locale's codepage as a number. */
+ if (DosQueryCp (sizeof (cp), cp, &cplen))
+ codeset = "";
+ else
+ {
+ sprintf (buf, "CP%u", cp[0]);
+ codeset = buf;
+ }
+ }
+
+#endif
+
+ if (codeset == NULL)
+ /* The canonical name cannot be determined. */
+ codeset = "";
+
+ /* Resolve alias. */
+ for (aliases = get_charset_aliases ();
+ *aliases != '\0';
+ aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1)
+ if (strcmp (codeset, aliases) == 0
+ || (aliases[0] == '*' && aliases[1] == '\0'))
+ {
+ codeset = aliases + strlen (aliases) + 1;
+ break;
+ }
+
+ /* Don't return an empty string. GNU libc and GNU libiconv interpret
+ the empty string as denoting "the locale's character encoding",
+ thus GNU libiconv would call this function a second time. */
+ if (codeset[0] == '\0')
+ codeset = "ASCII";
+
+ return codeset;
+}
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