/* * One file structure is allocated * for each open/creat/pipe call. * Main use is to hold the read/write * pointer associated with each open * file. */struct	file{	char	f_flag;	char	f_count;	/* reference count */	struct inode *f_inode;	/* pointer to inode structure */	union {		off_t	f_offset;	/* read/write character pointer */		struct chan *f_chan;	/* mpx channel pointer */	} f_un;};extern struct file file[];	/* The file table itself *//* flags */#define	FREAD	01#define	FWRITE	02#define	FPIPE	04#define FMPX	010#define	FMPY	020#define	FMP	030#define	FKERNEL	040