From VMS to UNIX

[Dan Klein]

Yes, I guess I stand corrected - the Unix primitive is read().  And all
the other calls are just macros on top of them.  The problem I have
encountered is that they are inconsistantly implemented, and well, we
can flame back and forth about this point for weeks.  Both Unix and VMS
have their shortcomings on all counts.

To answer another point, you *can* implement your own command language in
VMS.  Yes, you *initially* have the choice of either DCL or MCR (and in
a little while, VNX), but after that, you can do as you please.  Look at
HCR's Unity or EUNICE.  Someone even did a history/command completion system
for DCL.  The *nice* thing about VMS (or the bad thing, depending on where
you look) is that you start out *on top of* DCL.  This gives you the advantage
of a bailout point, and also gives you the ability to call on the existing
DCL primitives (you don't have to reinvent the wheel).  Both sh and csh have
to implement their own command scanners (from scratch), while EUNICE simply
uses the existing DCL scanner.  There are wins and loses to both.

		-Dan Klein, Mellon Institute, Pittsburgh