BFile bf_open (const char *name, int block_size, int wflag);
int bf_read (BFile bf, int no, int offset, int num, void *buf);
int bf_write (BFile bf, int no, int offset, int num, const void *buf);
BFile bf_open (const char *name, int block_size, int wflag);
int bf_read (BFile bf, int no, int offset, int num, void *buf);
int bf_write (BFile bf, int no, int offset, int num, const void *buf);