From: Ken Bloom <kbloom@...>
Date: 2008-04-26T00:40:07+09:00
Subject: Re: Find.prune if ( filename[-5,5] != ".java") is odd?

On Fri, 25 Apr 2008 07:28:42 -0500, Martin Elzen wrote:

> Hi all.
> 
> Today I had to do a recursive touch on all Java files in a certain
> directory.  Since I recently found that super cool ruby Find example I
> figured I'd use that.  However, my first try at a solution didn't work. 
> In the end I just changed the script a bit and now it does work as
> intended, but...  I really don't understand why the first version of the
> example didn't work...  It's the Ruby 1.8.6 1-click-installer version,
> if that matters.
> 
> 
> require "find"
> 
> 
> Find.find( "c:/usd70.senior.2008.04.14.copy" ) do |filename|
>   Find.prune if filename == "."
>   Find.prune if (filename.size < 6) # shortest interesting filename ==
>   "a.java"
> 
>   # first try, if I don't comment-out the following line it just does
>   not work as intended... #Find.prune if ( filename[-5,5] != ".java") #
>   string doesn't end with "java" ? #`touch #{filename}`
> 
> 
>   `touch #{filename}` if filename[-5,5] == ".java"
> 
> end

Find.prune is the wrong tool, period.

Find.find will yield all of the subdirectory names as well, and running 
Find.prune on a subdirectory will prevent Find from descending into that 
subdirectory (thereby saving time and ignoring its contents). But 
Find.prune will *not* jump to the next iteration of the loop. It will 
continue to the end of the block before moving on to the next file.

So I think you want
next if ...
instead.



-- 
Ken (Chanoch) Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu/~kbloom1/