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From: tjt@kobold.UUCP (T.J.Teixeira)
Newsgroups: net.cog-eng
Subject: Re: Re: expert-friendly: are long names - (nf)
Message-ID: <212@kobold.UUCP>
Date: Fri, 2-Dec-83 02:20:32 EST
Article-I.D.: kobold.212
Posted: Fri Dec  2 02:20:32 1983
Date-Received: Sun, 4-Dec-83 04:35:27 EST
References: <4246@uiucdcs.UUCP>
Organization: Masscomp, Westford, MA
Lines: 37

Reading Scott Preece's article jogged my memory on where I had run into
trouble with multi-component commands.  Both TOPS-20 (Tenex) and VMS
make heavy use of multi-component commands.  For example, in VMS there
are lots of commands of the form "SET ...".  To change your current
directory you use "SET DEFAULT device-name", to change modes on your terminal
you use "SET TERMINAL [:device-name]/qualifiers".  However, to set the
value of a logical name, you use "DEFINE logical-name equiv-name".
TOPS-20 uses a similar scheme, although "SET" is less ubiquitous.

The problem comes in when you aren't quite sure what command you need
to invoke next.  I agree with Scott that apropos is a good tool here,
although apropos is no better than the words used in the NAME line of
the manual page (try 'apropos delete' -- for 4.1BSD the only hit is the
dbm(3x) routines!).  The HELP command in VMS was not quite as good, but
was serviceable.  I no longer remember if it allowed wild cards in early
components such as "HELP * TERMINAL", but it wasn't too hard to
converge on things by the sequence "HELP", "HELP SET", "HELP SET
TERMINAL".

I found TOPS-20 *much* harder to deal with.  The HELP database on
TOPS-20 only seems to describe subsystems and not the commands built
into the command interpreter (EXEC).  Instead, you have to use a
combination of queries to the wildcard matcher and some inspired free
association.  Even then, the *only* help you get online are the
parenthesized guidewords.  You cannot find out about what choices are
available for component n without having specified components 1 to n-1.
In addition, far too many of the subsystems (and perhaps some of the
commands) have guidewords that only specify the *type* of the argument
(e.g. (FILE NAME)) and not the *use* of the argument (is it a source
file or a destination file).

Probably the object lesson here is: just as a "real programmer" can
write Fortran programs in *any* language, you can have deficiencies in
a command language no matter what model you follow.
-- 
	Tom Teixeira,  Massachusetts Computer Corporation.  Westford MA
	...!{ihnp4,harpo,decvax,ucbcad,tektronix}!masscomp!tjt   (617) 692-6200