void bseek(struct fastbuf *f, sh_off_t pos, int whence);
void bsetpos(struct fastbuf *f, sh_off_t pos);
void brewind(struct fastbuf *f);
void bseek(struct fastbuf *f, sh_off_t pos, int whence);
void bsetpos(struct fastbuf *f, sh_off_t pos);
void brewind(struct fastbuf *f);