From: Daniel Berger <djberg96@...>
Date: 2007-09-29T06:24:32+09:00
Subject: Re: is there to invoke 'previous' in Find? (or refresh the current path?)



On Sep 28, 1:12 pm, Daniel Berger <djber...@gmail.com> wrote:
> On Sep 27, 4:10 pm, "dtow...@gmail.com" <dtow...@gmail.com> wrote:
>
>
>
> > I am writing a small script which recursively goes down a dir
> > hierarchy, and when it reaches a set of files, it applies a 3rd party
> > application which modifies those files, and prepends the name with
> > "Mod-".
>
> > So for example, if i had a directory with only 1 file: C:\myDir
> > \myFile.txt, and I ran the app, I would end up with the following
> > files in c:\myDir
>
> > myFile.txt
> > Mod-myFile.txt
>
> > Basically, what i want to do is traverse down the hierarchy, when i
> > reach a set of files, call the app on that directory, then delete the
> > original, and rename the new file so that the "Mod-" is removed.
> > Unfortunately, the Find function doesnt see the newly created file,
> > and thus i cant delete & rename. My code looks something like this:
>
> > Find.find(startingDir) do |path|
> >   if File.directory?(path)
> >         next
> >   else
> >         system("myapp #{path}")
> >         puts path
> >         if File.basename(path) =~ /^Mod-/
> >           if File.exists?(path.sub('Mod-', ''))
> >                 File.delete(path.sub('Mod-', ''))
> >           end
> >         File.rename(path, path.sub('Mod-', ''))
> >         end
> >   end
> > end
>
> > I was wondering if there was a way to reset the path one level up
> > (i.e. where "puts path" is above), that way the current directory
> > would be refreshed, and the new files would be recognized.
>
> I don't think so. You'll probably have to use Dir.glob, keep a
> separate array of paths already visited and manually rewind back to
> your queue.
>
> You post does give me some devilish ideas for my file-find library

<snip>

Ok, here's what I came up with. First, I added a Rule#previous method,
which shows you the file you iterated over previously (or nil, if it's
the first match). With this in place you can do something like this:

require 'file/find'

rule = File::Find.new(
   :name => "z*.h",
   :path => "/my/include/sys"
)

rule.find{ |file|
   if file == 'zone.h'
      # Rename zone.h
      rule.rewind(rule.previous)
   else
      puts file
   end
}

The rewind code isn't the zippiest thing, but it works.

How does that look?

Regards,

Dan