3 * check_charset.c -- routines for character sets
7 * This code is Copyright (c) 2002, by the authors of nmh. See the
8 * COPYRIGHT file in the root directory of the nmh distribution for
9 * complete copyright information.
13 #ifdef HAVE_LANGINFO_H
14 # include <langinfo.h>
19 * Get the current character set
24 char *charset = getenv ("MM_CHARSET");
25 #if defined(HAVE_NL_LANGINFO) && defined(CODESET)
27 charset = norm_charmap(nl_langinfo (CODESET));
34 * Check if we can display a given character set natively.
35 * We are passed the length of the initial part of the
36 * string to check, since we want to allow the name of the
37 * character set to be a substring of a larger string.
41 check_charset (char *str, int len)
43 static char *mm_charset = NULL;
44 static char *alt_charset = NULL;
48 /* Cache the name of our default character set */
50 if (!(mm_charset = get_charset ()))
51 mm_charset = "US-ASCII";
52 mm_len = strlen (mm_charset);
54 /* US-ASCII is a subset of the ISO-8859-X and UTF-8 character sets */
55 if (!strncasecmp("ISO-8859-", mm_charset, 9) ||
56 !mh_strcasecmp("UTF-8", mm_charset)) {
57 alt_charset = "US-ASCII";
58 alt_len = strlen (alt_charset);
62 /* Check if character set is OK */
63 if ((len == mm_len) && !strncasecmp(str, mm_charset, mm_len))
65 if (alt_charset && (len == alt_len) && !strncasecmp(str, alt_charset, alt_len))
73 * Return the name of the character set we are
74 * using for 8bit text.
77 write_charset_8bit (void)
79 static char *mm_charset = NULL;
82 * Cache the name of the character set to
85 if (!mm_charset && !(mm_charset = get_charset ()))
86 mm_charset = "x-unknown";