Re: autotest vs. in-use directories

[Ralf Wildenhues]

Hi Eric,

* Eric Blake wrote on Thu, Apr 09, 2009 at 08:24:29PM CEST:
> Ralf Wildenhues <Ralf.Wildenhues <at> gmx.de> writes:
> 
> > it's really sad that, while Cygwin adds POSIX-like functionality, it
> > seems it always only gets it half-right, and that then requires other
> > hacks in other tools to work around the remaining deficiencies.  :-/
> 
> Actually, this one turned out to be a gcc upgrade issue!
> http://cygwin.com/ml/cygwin/2009-04/msg00267.html

Oops.  Interesting.  And definitely nice of them to fix it so quickly.

> But the point of this patch is not cygwin's (temporary) inability to recreate 
> an in-use directory, but the fact that deleting an in-use directory has other 
> negative effects on all platforms, leading to confusing messages when your 
> interactive shell's current working directory is suddenly made stale even 
> though a (new) directory by the name of $PWD still exists.

Yes, ok.

> > Just for safety, I'd remove the directory last.  Also, why is this not
> > sufficient?
> >    rm -fr "$at_group_dir"/* "$at_group_dir"/.[!.]* || ...
> > 
> > since this is only globbing, not regular expressions.
> 
> No, the point of the above change is that I'm NOT deleting the current 
> directory.  Rather, I'm using ALL THREE globs to collectively name every 
> possible file within the directory (think 'a', '...', and '.a', each of which 
> only match one of the three globs),

Yeah, I'll blame it on me not being concentrated any more when I wrote
that.

> so that after the rm call, the directory 
> should still exist but be empty.  My question was more whether I am correct 
> that 3 globs is sufficient to cover all cases, and that we don't need 4, and 
> that no one else knows any trick to make it possible to reduce to 2 globs.

I don't see any currently.  But adding a test case that proves that all
three globs are necessary would be prudent.

Cheers,
Ralf