diff options
Diffstat (limited to 'intl/localcharset.c')
| -rw-r--r-- | intl/localcharset.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/intl/localcharset.c b/intl/localcharset.c new file mode 100644 index 000000000..22e09e410 --- /dev/null +++ b/intl/localcharset.c @@ -0,0 +1,271 @@ +/* Determine a canonical name for the current locale's character encoding. + + Copyright (C) 2000-2001 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 <haible@clisp.cons.org>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#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 + +#ifndef WIN32 +# if HAVE_LANGINFO_CODESET +# include <langinfo.h> +# else +# if HAVE_SETLOCALE +# include <locale.h> +# endif +# endif +#else /* WIN32 */ +# define WIN32_LEAN_AND_MEAN +# include <windows.h> +#endif + +#ifndef DIRECTORY_SEPARATOR +# define DIRECTORY_SEPARATOR '/' +#endif + +#ifndef ISSLASH +# define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR) +#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 char * volatile charset_aliases; + +/* Return a pointer to the contents of the charset.alias file. */ +static const char * +get_charset_aliases () +{ + char *cp; + + cp = charset_aliases; + if (cp == NULL) + { +#ifndef WIN32 + FILE *fp; + const char *dir = 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 = malloc (res_size + 1); + } + else + { + res_size += l1 + 1 + l2 + 1; + res_ptr = 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 /* 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"; +#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; + +#ifndef WIN32 + +# 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 + +#else /* WIN32 */ + + static char buf[2 + 10 + 1]; + + /* Win32 has a function returning the locale's codepage as a number. */ + sprintf (buf, "CP%u", GetACP ()); + 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; + } + + return codeset; +} |