Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!usc!snorkelwacker!apple!motcsd!xdos!doug
From: doug@xdos.UUCP (Doug Merritt)
Newsgroups: comp.sys.amiga.tech
Subject: Re: SKsh completion bug.
Message-ID: <682@xdos.UUCP>
Date: 9 Mar 90 16:36:11 GMT
References: <8289@wpi.wpi.edu> <13920055@hpfelg.HP.COM> <392@icebox.nsc.com>
Reply-To: doug@xdos.UUCP (Doug Merritt)
Organization: Hunter Systems, Mountain View CA (Silicon Valley)
Lines: 46

In article <392@icebox.nsc.com> waggoner@icebox.UUCP (Mark Waggoner) writes:
>
>The only reason I can see for doing shell expansions is to provide a
>unix-like environment, which means you also need a bunch of unix-like
>commands that expect the wildcards to be expanded.

A little history here: this argument has been going on endlessly over
every non-Unix system in existence; i.e. the above is a popular argument.

The problems with that are:
	1) Pervasiveness/universality: if it's not in the shell, that
	   generally means that feature is not universally available.
	   So I have to remember which commands allow it, which do not,
	   which support one flavor of wildcarding, which allow another,
	   which use both, which have Super Wildcard Expansions, etc.
	   So this is also a "consistency/documentation" argument.
	   And this is precisely the problem I currently have.

	2) No, you don't need "unix-like commands". Essentially all
	   reasonable utilities support a command line list of files.
	   Even if they support wildcards, they will not object to
	   what appears to be a wildcard-free list of filenames typed
	   by hand.
	
	3) Duplication of effort/code size. When every command has its
	   own wildcard code, it not only wastes code space, it also
	   (probably more significantly) wastes the time of the developer
	   who had to reinvent the wheel one more time.

So, no, it's not just to provide a Unix-like environment. It's because
it's smart. The only (arguably) better way is to provide the facility
in a *standard* system library (ARP may reach this status but it ain't
there yet). This makes it a little less universal, in that some boneheads
will still write programs that don't *use* the system facility (as
previously established on all the O.S.'s that do this). But it gets
around the limited expansion space problem.

It also potentially allows wildcards to be used even in e.g. requesters,
which the shell approach does not.

If I misunderstood you, and we're in violent agreement on this :-),
my apologies.
	Doug
-- 
Doug Merritt		{pyramid,apple}!xdos!doug
Member, Crusaders for a Better Tomorrow		Professional Wildeyed Visionary