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From: rpw3@fortune.UUCP
Newsgroups: net.cog-eng
Subject: Re: Whoever said anything about flag=yes - (nf)
Message-ID: <2854@fortune.UUCP>
Date: Tue, 27-Mar-84 04:04:25 EST
Article-I.D.: fortune.2854
Posted: Tue Mar 27 04:04:25 1984
Date-Received: Wed, 28-Mar-84 00:49:39 EST
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Organization: Fortune Systems, Redwood City, CA
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#R:looking:-14100:fortune:29300006:000:2004
fortune!rpw3    Mar 26 22:11:00 1984

As far as remembering WHAT the possible options are, one of the niceties
of TOPS-10 SCAN was that certain switches were built into the scanner,
particularly /HELP and /HELP:SWITCHES. The former printed the help file
(if available) or a short in-core help string, and the latter dumped the
contents of the scanners parse table. /HELP:SWITCHES was ALWAYS a no-op
as far as running the program, so you didn't have to worry about the
program starting to work on you or going silent. (Type "cat" and wait
for a "usage" message... ;-} ) You would get something like:

	$ cat -help=opt
	Options are: spacecrunch, unbuffered, visible
	Builtin:     help, verbose, datesave
	$

The "builtins" are those options that are supplied by default in every
program in the scanner itself. They are not necessary IMPLEMENTED in the
scanner (except "help"), but the user knows that they will get parsed
correctly.

And then of course there is Tenex/TOPS-20, which allows a question mark
ANYWHERE, and it prints out all possible choices and lets you continue
typing. It works whether you type the question mark on a command, an option,
or on a filename. (To get a list of all commands, just type a "?" to a prompt!)
While some don't like that general style, it CAN certainly be done under UNIX,
as evidenced by the version of C-shell (called "ncsh"?) which is floating
around the UNIX community (orig. Ken Greer, HP) which implements the full
Twenex command recognition/completion. (To clarify what follows, typed-in
characters are in uppercase, though in real life they are lower):

	% CA<?>				where <?> is your "query" character
	cal camera cat
	% caT C<?>
	carny core cu.log
	% cat cU<!>			where <!> is your "completion" char
	  cat cu.log			(actually overtypes the <!>)
	...contents of cu.log ...
	%

We have lots of history to guide us, if we listen.

Rob Warnock

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