Reference Manual

NAME

devs - print information from the device switch table

devs [devnum | devname]

Command devs extracts information from the device switch table and formats it in a readable form. Each line of output contains information about a device or a pseudo-device. Columns give the major device number, device name, minor device number, owner's thread ID, device control block address and the device reference count.

If an argument is specified, only the entry matching the device number devnum or the device name devname is printed.

NAT32 supports the following device names and numbers:

WINDOW     0    /* class winm    */
CONSOLE    1    /* class win     */
MON        9    /* class mon     */
CB        10    /* class cb      */
WEB       11    /* class web     */
STDIO     12    /* class xio     */
STDIN     13    /* class sio     */
STDOUT    14    /* class sio     */
STDERR    15    /* class sio     */
NULLDEV   29    /* class null    */
DOS       30    /* class dos     */
NAMESPACE 47    /* class nam     */
PIPE      48    /* class pipm    */
WPF       65    /* class wpfm    */
SOCK     130    /* class sockm   */
UDP      147    /* class dgm     */
TCP      164    /* class tcpm    */

NAT32 uses an interesting reversal of the UNIX file system paradigm: whereas UNIX treats devices as files, NAT32 treats files as devices. This paradigm was first proposed by Douglas Comer of Purdue University. The concept has the major advantage that it allows all devices, including devices such as windows and sockets, that are not part of the Operating System's file system, to be supported in a uniform manner.

Note the diverse range of devices supported by the concept. In particular, note how WINDOW, PIPE, UDP, TCP and SOCK devices fit easily into Comer's paradigm.

A name mapping mechanism allows any instance of a device to be referenced by name.

close, names