#define	WRBIT	0100000
#define	TXTBIT	040000
#define	EOFBIT	020000
#define	ELNBIT	010000
#define	WINDOW	04000
#define	MAGIC	0252

struct file {
	char	*ptr;
	unsigned flags;
	char	*fname;
	int	ufd;
	int	size;
	int	count;
	int	buflen;
	char	bufadr[512];
};

#define	EXTFL(z)	((struct file *)(_hbase + _extfl[z]))