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author | Bruno Haible <bruno@clisp.org> | 2000-06-16 19:01:17 +0000 |
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committer | Bruno Haible <bruno@clisp.org> | 2000-06-16 19:01:17 +0000 |
commit | abd5754eacd67b2c627a75d5ea574f0fbbdafbe2 (patch) | |
tree | 2e5f6d494e27f148e3b759bea4850d5f2a37d050 /intl/localcharset.c | |
parent | d734a4c1fd58bc7522aa2ec8736526f69bfdb539 (diff) | |
download | external_gettext-abd5754eacd67b2c627a75d5ea574f0fbbdafbe2.zip external_gettext-abd5754eacd67b2c627a75d5ea574f0fbbdafbe2.tar.gz external_gettext-abd5754eacd67b2c627a75d5ea574f0fbbdafbe2.tar.bz2 |
Implementation of the locale_charset function.
Diffstat (limited to 'intl/localcharset.c')
-rw-r--r-- | intl/localcharset.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/intl/localcharset.c b/intl/localcharset.c new file mode 100644 index 0000000..932473c --- /dev/null +++ b/intl/localcharset.c @@ -0,0 +1,228 @@ +/* Determine a canonical name for the current locale's character encoding. + + Copyright (C) 2000 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 HAVE_LANGINFO_CODESET +# include <langinfo.h> +#else +# if HAVE_SETLOCALE +# include <locale.h> +# endif +#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. */ +/* 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) + { + 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; + } + } + + charset_aliases = cp; + if (file_name != NULL) + free (file_name); + } + + 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 or NULL. */ + +#ifdef STATIC +STATIC +#endif +const char * +locale_charset () +{ + const char *codeset; + const char *aliases; + +#if HAVE_LANGINFO_CODESET + + /* Most systems support nl_langinfo (CODESET) nowadays. */ + codeset = nl_langinfo (CODESET); + +#else + + /* On old systems which lack it, use setlocale and getenv. */ + const char *locale = NULL; + +# if HAVE_SETLOCALE + 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 + + if (codeset != NULL && codeset[0] != '\0') + { + /* Resolve alias. */ + for (aliases = get_charset_aliases (); + *aliases != '\0'; + aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1) + if (!strcmp (codeset, aliases)) + { + codeset = aliases + strlen (aliases) + 1; + break; + } + } + + return codeset; +} |