+bool
+is_encoding_ascii_compatible (const char *encoding)
+{
+ struct encoding_info e;
+
+ get_encoding_info (&e, encoding);
+ return e.is_ascii_compatible;
+}
+
+bool
+is_encoding_ebcdic_compatible (const char *encoding)
+{
+ struct encoding_info e;
+
+ get_encoding_info (&e, encoding);
+ return e.is_ebcdic_compatible;
+}
+
+/* Returns true if iconv can convert ENCODING to and from UTF-8,
+ otherwise false. */
+bool
+is_encoding_supported (const char *encoding)
+{
+ return (create_iconv ("UTF-8", encoding)
+ && create_iconv (encoding, "UTF-8"));
+}
+
+/* Returns true if E is the name of a UTF-8 encoding.
+
+ XXX Possibly we should test not E as a string but its properties via
+ iconv. */
+bool
+is_encoding_utf8 (const char *e)
+{
+ return ((e[0] == 'u' || e[0] == 'U')
+ && (e[1] == 't' || e[1] == 'T')
+ && (e[2] == 'f' || e[2] == 'F')
+ && ((e[3] == '8' && e[4] == '\0')
+ || (e[3] == '-' && e[4] == '8' && e[5] == '\0')));
+}
+\f
+static struct encoding_category *categories;
+static int n_categories;
+
+static void SENTINEL (0)
+ add_category (size_t *allocated_categories, const char *category, ...)
+{
+ struct encoding_category *c;
+ const char *encodings[16];
+ va_list args;
+ int i, n;
+
+ /* Count encoding arguments. */
+ va_start (args, category);
+ n = 0;
+ while ((encodings[n] = va_arg (args, const char *)) != NULL)
+ {
+ const char *encoding = encodings[n];
+ if (!strcmp (encoding, "Auto") || is_encoding_supported (encoding))
+ n++;
+ }
+ assert (n < sizeof encodings / sizeof *encodings);
+ va_end (args);
+
+ if (n == 0)
+ return;
+
+ if (n_categories >= *allocated_categories)
+ categories = x2nrealloc (categories,
+ allocated_categories, sizeof *categories);
+
+ c = &categories[n_categories++];
+ c->category = category;
+ c->encodings = xmalloc (n * sizeof *c->encodings);
+ for (i = 0; i < n; i++)
+ c->encodings[i] = encodings[i];
+ c->n_encodings = n;
+}
+
+static void
+init_encoding_categories (void)
+{
+ static bool inited;
+ size_t alloc;
+
+ if (inited)
+ return;
+ inited = true;
+
+ alloc = 0;
+ add_category (&alloc, "Unicode", "UTF-8", "UTF-16", "UTF-16BE", "UTF-16LE",
+ "UTF-32", "UTF-32BE", "UTF-32LE", NULL_SENTINEL);
+ add_category (&alloc, _("Arabic"), "IBM864", "ISO-8859-6", "Windows-1256",
+ NULL_SENTINEL);
+ add_category (&alloc, _("Armenian"), "ARMSCII-8", NULL_SENTINEL);
+ add_category (&alloc, _("Baltic"), "ISO-8859-13", "ISO-8859-4",
+ "Windows-1257", NULL_SENTINEL);
+ add_category (&alloc, _("Celtic"), "ISO-8859-14", NULL_SENTINEL);
+ add_category (&alloc, _("Central European"), "IBM852", "ISO-8859-2",
+ "Mac-CentralEurope", "Windows-1250", NULL_SENTINEL);
+ add_category (&alloc, _("Chinese Simplified"), "GB18030", "GB2312", "GBK",
+ "HZ-GB-2312", "ISO-2022-CN", NULL_SENTINEL);
+ add_category (&alloc, _("Chinese Traditional"), "Big5", "Big5-HKSCS",
+ "EUC-TW", NULL_SENTINEL);
+ add_category (&alloc, _("Croatian"), "MacCroatian", NULL_SENTINEL);
+ add_category (&alloc, _("Cyrillic"), "IBM855", "ISO-8859-5", "ISO-IR-111",
+ "KOI8-R", "MacCyrillic", NULL_SENTINEL);
+ add_category (&alloc, _("Cyrillic/Russian"), "IBM866", NULL_SENTINEL);
+ add_category (&alloc, _("Cyrillic/Ukrainian"), "KOI8-U", "MacUkrainian",
+ NULL_SENTINEL);
+ add_category (&alloc, _("Georgian"), "GEOSTD8", NULL_SENTINEL);
+ add_category (&alloc, _("Greek"), "ISO-8859-7", "MacGreek", NULL_SENTINEL);
+ add_category (&alloc, _("Gujarati"), "MacGujarati", NULL_SENTINEL);
+ add_category (&alloc, _("Gurmukhi"), "MacGurmukhi", NULL_SENTINEL);
+ add_category (&alloc, _("Hebrew"), "IBM862", "ISO-8859-8-I", "Windows-1255",
+ NULL_SENTINEL);
+ add_category (&alloc, _("Hebrew Visual"), "ISO-8859-8", NULL_SENTINEL);
+ add_category (&alloc, _("Hindi"), "MacDevangari", NULL_SENTINEL);
+ add_category (&alloc, _("Icelandic"), "MacIcelandic", NULL_SENTINEL);
+ add_category (&alloc, _("Japanese"), "EUC-JP", "ISO-2022-JP", "Shift_JIS",
+ NULL_SENTINEL);
+ add_category (&alloc, _("Korean"), "EUC-KR", "ISO-2022-KR", "JOHAB", "UHC",
+ NULL_SENTINEL);
+ add_category (&alloc, _("Nordic"), "ISO-8859-10", NULL_SENTINEL);
+ add_category (&alloc, _("Romanian"), "ISO-8859-16", "MacRomanian",
+ NULL_SENTINEL);
+ add_category (&alloc, _("South European"), "ISO-8859-3", NULL_SENTINEL);
+ add_category (&alloc, _("Thai"), "ISO-8859-11", "TIS-620", "Windows-874",
+ NULL_SENTINEL);
+ add_category (&alloc, _("Turkish"), "IBM857", "ISO-8859-9", "Windows-1254",
+ NULL_SENTINEL);
+ add_category (&alloc, _("Vietnamese"), "TVCN", "VISCII", "VPS",
+ "Windows-1258", NULL_SENTINEL);
+ add_category (&alloc, _("Western European"), "ISO-8859-1", "ISO-8859-15",
+ "Windows-1252", "IBM850", "MacRoman", NULL_SENTINEL);
+}
+
+/* Returns an array of "struct encoding_category" that contains only the
+ categories and encodings that the system supports. */
+struct encoding_category *
+get_encoding_categories (void)
+{
+ init_encoding_categories ();
+ return categories;
+}
+
+/* Returns the number of elements in the array returned by
+ get_encoding_categories(). */
+size_t
+get_n_encoding_categories (void)
+{
+ init_encoding_categories ();
+ return n_categories;
+}