+char recode_byte (const char *to, const char *from, char);
+
+char *recode_string (const char *to, const char *from,
+ const char *text, int len);
+char *recode_string_pool (const char *to, const char *from,
+ const char *text, int length, struct pool *);
+struct substring recode_substring_pool (const char *to, const char *from,
+ struct substring text, struct pool *);
+
+size_t recode_string_len (const char *to, const char *from,
+ const char *text, int len);
+
+bool valid_encoding (const char *enc);