``file descriptor'' pseudo-device driver for 4.2BSD

[Steven Bellovin]

The 8th Edition convention is to use /dev/fd/N, not /dev/fdN.  Some versions
of the Korn shell and the Eighth edition shell know about this naming convention;
they support things like

	diff (rsh a cat /etc/passwd) (rsh b cat /etc/passwd)
	
/dev/fd/0, /dev/fd/1, and /dev/fd/2 are also known as /dev/stdin, /dev/stdout, and
/dev/stderr.