_IOC               62 sys/ioccom.h   #define	_IO(g,n)	_IOC(IOC_VOID,	(g), (n), 0)
_IOC               63 sys/ioccom.h   #define	_IOR(g,n,t)	_IOC(IOC_OUT,	(g), (n), sizeof(t))
_IOC               64 sys/ioccom.h   #define	_IOW(g,n,t)	_IOC(IOC_IN,	(g), (n), sizeof(t))
_IOC               66 sys/ioccom.h   #define	_IOWR(g,n,t)	_IOC(IOC_INOUT,	(g), (n), sizeof(t))