Path: utzoo!attcan!uunet!glyph!nichiren
From: nichiren@glyph.UUCP (Andy Heffernan)
Newsgroups: comp.unix.questions
Subject: Re: Strangeness in shell
Message-ID: <470@glyph.UUCP>
Date: 26 Jul 89 04:52:38 GMT
References: <432@mccc.UUCP> <9700009@osiris.cso.uiuc.edu> <2277@auspex.auspex.com>
Reply-To: nichiren@glyph.UUCP (Andy Heffernan)
Organization: Elvis Needs Boats
Lines: 34

In article <2277@auspex.auspex.com> guy@auspex.auspex.com (Guy Harris) writes:
>> Ummm... I had always learned (obviously flawed) that the single quotes 
>>prevented expansion of ANYTHING....
>
	[much deleted]
>
>>If you have no files ending in  z  , then why does it not return a null 
>>string for the '*z' version ?
>
>Because that's the way the Bourne shell works.  If a filename pattern
>doesn't match any file names, it is left unchanged, not expanded to a
>null string or a null list.

Yes, indeed.

For a simple-minded example of this feature in action,
we Bourne/Korn shell users can get away with:

$ uucp whereever!~uucp/goodstuff/* ~uucp/cache

to get everything in whereever's public goodstuff directory.  Unless
your current directory contains a directory named "whereever!~uucp"
which contains a directory named "goodstuff", which in turn has some
non-dot files in it, the first argument to the command will expand to
itself, and so get passed to 'whereever' for expansion. 

For C-shell users, at least the * in the above command needs quoting
against interpretation, and I guess the ! as well.  (Beats me, I just ^P.)

-- 
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Andy Heffernan              uunet!glyph!nichiren            [1222 - 1282]
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	   "Dogpile on the rabbit!  Dogpile on the rabbit!"