void replstr(char **p, char *n);
char *base64encode(char *data, size_t datalen);
char *base64decode(char *data, size_t *datalen);
+int hexdigit(char c);
int bbtreedel(struct btree **tree, void *item, int (*cmp)(void *, void *));
void freebtree(struct btree **tree, void (*ffunc)(void *));
int bbtreeput(struct btree **tree, void *item, int (*cmp)(void *, void *));