1 files changed, 89 insertions, 0 deletions
diff --git a/src/alias.c b/src/alias.c
new file mode 100644
index 0000000..ebc1b78
--- /dev/null
+++ b/src/alias.c
@@ -0,0 +1,89 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "unicode/charsets.h"
+#include "unicode/encoding.h"
+
+#include "internal.h"
+
+struct table_entry {
+	const char *alias;
+	const char *encname;
+};
+
+/* This table contains special cases to allow us to use UnicodeLib sensibly. */
+static const struct table_entry mapping_table[] = {
+	{"/UTF-7/UNICODE-1-1-UTF-7/UNICODE-2-0-UTF-7/", "UTF-7" },
+	{"/ISO-10646-UCS-4/UCS-4/UTF-32/", "ISO-10646-UCS-4" },
+	{"/UTF-16/UCS-2/ISO-10646-UCS-2/UNICODE-1-1/UNICODE-2-0/", "UTF-16" },
+	{"/ISO-2022/", "ISO-2022" },
+};
+
+#define TABLE_SIZE (sizeof(mapping_table) / sizeof(mapping_table[0]))
+
+/**
+ * Look up an encoding number, based on its name
+ *
+ * \param name The encoding name
+ * \return The encoding number, or 0 if not found.
+ */
+int iconv_encoding_number_from_name(const char *name)
+{
+	unsigned int i;
+	char buf[256];
+	struct canon *c;
+
+	if (!name)
+		return 0;
+
+	snprintf(buf, sizeof buf, "/%s/", name);
+
+	/* convert to upper case */
+	for (i = 0; i != strlen(buf); i++) {
+		if (buf[i] >= 'a' && buf[i] <= 'z')
+			buf[i] = buf[i] - 32;
+	}
+
+	for (i = 0; i != TABLE_SIZE; i++)
+		if (strstr(mapping_table[i].alias, buf) != NULL)
+			return encoding_number_from_name(mapping_table[i].encname);
+
+	c = alias_canonicalise(name);
+	if (!c)
+		return 0;
+
+	return encoding_number_from_name(c->name);
+}
+
+/**
+ * Look up an encoding name, based on its MIB number
+ *
+ * \param number  The encoding MIB number
+ * \return Pointer to encoding name, or NULL if not found
+ */
+const char *iconv_encoding_name_from_number(int number)
+{
+	const char *ret = NULL;
+	/* This is a PITA - UnicodeLib doesn't have a call to do this,
+	 * so implement it ourselves. */
+	switch (number) {
+		case csUnicode11UTF7:
+			ret = mapping_table[0].alias;
+			break;
+		case csUCS4:
+			ret = mapping_table[1].alias;
+			break;
+		case csUnicode11:
+			ret = mapping_table[2].alias;
+			break;
+		case csVenturaMath:
+			ret = mapping_table[3].alias;
+			break;
+		default:
+			ret = mibenum_to_name(number);
+			break;
+	}
+
+	return ret;
+}