intro(7)							      intro(7)

NAME    [Toc]    [Back]

     intro - introduction to special files

DESCRIPTION    [Toc]    [Back]

     This section describes various special files that refer to	specific
     hardware peripherals, and IRIX system device drivers.  STREAMS (see
     intro(2)) software	drivers, modules, and the STREAMS-generic set of
     ioctl(2) system calls are also described.

     For hardware-related files, the names of the entries are generally
     derived from names	for the	hardware, as opposed to	the names of the
     special files themselves.	Characteristics	of both	the hardware device
     and the corresponding IRIX	system device driver are discussed where
     applicable.

     Disk device filenames are described in dks(7M).

     Tape device filenames are in the following	format:

	  /dev/rmt/typecontrollerdunit{nr}{ns|s}{v}{stat}{.density}{c}

     Where:

     type	  Identifies the controller type.

     controller	  Indicates the	controller number.

     unit	  Indicates the	device attached	to the controller.

     nr		  Indicates a non rewinding interface.

     ns		  Indicates bytes are not swapped.  This should	be used	for
		  all tape types other than QIC, in almost all cases.  It
		  should also be used for QIC tapes imported from or exported
		  to systems other than	IRIX.

     s		  Indicates bytes are swapped by the driver, primarily for
		  backwards compatibility with older Silicon Graphics systems.

     v		  Indicates that the variable blocksize	device should be used.
		  This device writes a single logical block per	read or	write
		  system call.	The fixed block	device transfers 1 or more
		  logical blocks per read or write system call.	 Variable mode
		  is preferred on 9-track, DAT,	and often when importing or
		  exporting 8mm	media from non-IRIX systems.

     stat	  A special device that	can be used only for the MTIOCGET
		  ioctl.  All other I/O	requests and ioctls fail with the
		  EINVAL errno.






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intro(7)							      intro(7)



     .density	  Optionally specifies the media density, where	appropriate.
		  For devices with only	one density setting, density is
		  omitted.  The	. is used to keep the unit from	visually
		  merging with the density.

     c		  indicates a device which performs hardware data compression
		  and should not be confused with density.

     The /dev/mt directory exists as a link to /dev/rmt	as a portability aid;
     IRIX does not support block mode tape access.  Not	all tape types support
     all of these options.  For	backwards compatibility, a tape	device with
     neither ns, nor s is created.  It is normally the same device as the s
     device for	QIC tapes and ns for all other tape types.

SEE ALSO    [Toc]    [Back]

     MAKEDEV(1M), fx(1M), hinv(1M), mt(1), prtvtoc(1M).

NOTE    [Toc]    [Back]

     The other devices in section 7 can	be listed with:

	  man -w 7 '*'

     or	all of them can	be read	with:

	  man 7	'*'


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