intro - introduction to special files
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
Disk device filenames are described in dks(7M).
Tape device filenames are in the following format:
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
.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.
MAKEDEV(1M), fx(1M), hinv(1M), mt(1), prtvtoc(1M).
The other devices in section 7 can be listed with:
man -w 7 '*'
or all of them can be read with:
man 7 '*'
PPPPaaaaggggeeee 2222 [ Back ]