void btr_consume(struct btr_node *btrn, size_t numbytes);
int btr_exec(struct btr_node *btrn, const char *command, char **value_result);
int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result);
void btr_consume(struct btr_node *btrn, size_t numbytes);
int btr_exec(struct btr_node *btrn, const char *command, char **value_result);
int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result);