The Directory Walker revisited

wouter wouter.abraham at pi.be
Wed Sep 3 06:21:00 EDT 2003


On woensdag, sep 3, 2003, at 02:44 Europe/Brussels, 
use-revolution-request at lists.runrev.com wrote:

> Message: 2
> Date: Wed, 3 Sep 2003 07:34:02 +1000
> Subject: Re: The Directory Walker revisited
> From: David Vaughan <dvk at dvkconsult.com.au>
> To: use-revolution at lists.runrev.com
> Reply-To: use-revolution at lists.runrev.com
>
>
> On Tuesday, Sep 2, 2003, at 22:19 Australia/Brisbane, wouter
> <wouter.abraham at pi.be> wrote:
>
> snip
>
>>> Now directories nested 1000 deep seems unusual.
>>
>> That is true but the amount of recursion is not  equal to the depth of
>> the directories.
>
> That rather depends on whether you are using pre-, end- or post-order
> processing within the recursion. Walking the entire breadth and depth
> of the directory tree before processing any data would be a bit 
> unusual.

Yes but that is precisely what will make the recursive handlers meet 
their limit if it  a directory tree is a really wide and/ or deep. It 
is the amount of recursion that counts. It is not realy a question of 
the "possibility" of using recursive handlers on directories (the 
answer will be yes up to the recursionLimit). The question is : are 
recursive handlers efficient enough to be used for this kind of work if 
they can bump into a recursionLimit before ending their task.
Personally I like recursive handlers and will use them if possible, but 
not in this case.

>
>> It is equal to the total amount of directories. And this number can
>> easily surpass 1000.
>>
> I did not see the actual walker which started this thread but I and
http://www.sonsothunder.com/devres/metacard/tips/file007.htm

> others have posted recursive walkers "years" ago which used a
> depth-first search with pre- or end-order processing, and have not hit
> these limits. As Dar suggests, I doubt they would have any problem
> processing an entire OS X volume.

I have been searching for this recursive walkers from  "years" ago but 
couldn't find those with "depth-first search with pre- or end-order 
processing". Can you please post the url.
The other recursive ones are "all" bumping into the recursionLimit. 
Except one you mentioned at :
http://lists.runrev.com/pipermail/use-revolution/2002-May/004353.html
which points to Ben Rubinstein's directory walking function. Which is 
not a real recursive handler, but a repeat loop buried in a function.  
Only this script as it is, will not work and has to be corrected.

> regards
> David

Greetings
WA




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