Re: [9fans] How can I shift a variable other than ?

[erik quanstrom <quanstro@coraid.com>]

strictly speaking, <> could be implemented with no help
from rc (and more generally) as in

	boxredir fdin fdout cmd

okay, that's a bit silly, but the point between essential and
non-essential is in the eye of the beholder.

odd digression:

in the late 60s the fad was to rewrite bigger instruction sets in
terms of smaller ones (the metric was # of instructions).  somebody
had a 16 instruction set that someone else reimplemented in 8
instructions.  the apollo guidance computer had 12 instructions and
a few magic memory locations.  it was finally determinted you could get by on
one instruction --- some variation on predecrement and branch
if negative.  "look ma, no instructions."  unfortunately, this machine
was somewhat difficult to program

- erik