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Date:	Tue, 02 Dec 2008 14:38:01 +0100
Reply-To:	"Christian Franke" <Christian DOT Franke AT t-online DOT de>
To:	cygwin AT cygwin DOT com
Subject:	Re: Avoid duplicate names in /proc/registry (which may crash find) ?
From:	"Christian Franke" <Christian DOT Franke AT t-online DOT de>
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Corinna Vinschen wrote:
> ...
> 
> Some random thoughts:
> 
> - Do we really need d_type support in the registry?  How often is that
> actually used?
> 

/proc/registry is probably rarely used, so d_type support is not
important.
But adding it would be trivial and the effect is significant:
Speed up of  "oldfind" (which does not crash :-) is >= 2.


> - If find crashes in this situation, isn't this a bug in find which
> should be fixed in find?
> 

Yes. As far as I understand POSIX, it does not require "directory
snapshot" semantics for readdir(). So if e.g. a directory "foo" is
replaced by a file "foo" during a readdir() sequence, duplicate names
with different d_type may occur (at least in theory :-)


> - /proc/registry is a convenience for reading the registry.  Due to
> some funny definitions of the registry it's not a full solution.  You
> can't write this way, you can't even access the "(Default)" key
> values.

Access to (Default) works for me with "/proc/registry/.../key/@"

> I personally don't worry if some border cases don't work.  For the
> border cases and for the full access we have regtool.
> 
> Having said that, I really don't know what's the best solution for
> these problems would be.  None of the above ideas are very attractive.
> For instance, in idea 1, the path would actually be
> 
> /proc/registry/HKEY_LOCAL_MACHINE.key/SOFTWARE.key/Cygwin.key/blub.val
> 

or:

3.  Add an extension (describing its type) to value only:

/proc/registry/HKEY_LOCAL_MACHINE/SOFTWARE/Cygwin/blub.type

But then a possible "somekey.type" should be escaped ...


> Shouldn't we rather defer these border cases to regtool?
> 

Yes, further enhancements to /proc/registry are probably not worth the
effort.

Hmm... "/proc/registry/..." pathnames as an alternative for the
KEY/VALUE parameters of regtool would allow to use shell tab-completion
and therefore enhance usability (?).

Christian




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