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.
15 * Check if we can display a given character set natively.
16 * We are passed the length of the initial part of the
17 * string to check, since we want to allow the name of the
18 * character set to be a substring of a larger string.
22 check_charset (char *str, int len)
24 static char *mm_charset = NULL;
25 static char *alt_charset = NULL;
29 /* Cache the name of our default character set */
31 if (!(mm_charset = getenv ("MM_CHARSET")))
32 mm_charset = "US-ASCII";
33 mm_len = strlen (mm_charset);
35 /* US-ASCII is a subset of the ISO-8859-X and UTF-8 character sets */
36 if (!strncasecmp("ISO-8859-", mm_charset, 9) ||
37 !strcasecmp("UTF-8", mm_charset)) {
38 alt_charset = "US-ASCII";
39 alt_len = strlen (alt_charset);
43 /* Check if character set is OK */
44 if ((len == mm_len) && !strncasecmp(str, mm_charset, mm_len))
46 if (alt_charset && (len == alt_len) && !strncasecmp(str, alt_charset, alt_len))
54 * Return the name of the character set we are
55 * using for 8bit text.
58 write_charset_8bit (void)
60 static char *mm_charset = NULL;
63 * Cache the name of the character set to
66 if (!mm_charset && !(mm_charset = getenv ("MM_CHARSET")))
67 mm_charset = "x-unknown";