From: Jerry Blanco <grblanco@...>
Date: 2007-06-15T05:47:08+09:00
Subject: Directory tree traversal fun

Hi,
I want to write a recursive file renamer. It will work such that given
the following:

c:\prov\foo1.txt
c:\prov\fooDir
c:\prov\fooDir\foo2.txt

you call rename("c:\\prov", "foo", "bar") and get

c:\prov\bar1.txt
c:\prov\barDir
c:\prov\barDir\bar2.txt

I wrote the following:

def rename(headOfTree, what, withWhat)
	p = Pathname.new(headOfTree)
	p.find() do |file|
		path = file.to_s #just to make it prettier
		File.rename(path, path.gsub("#{what}", withWhat)) if path.include?(what)
	end
end


The problem is that p.find() is top-to-bottom, so it renames in the
following order:
1. c:\prov\bar1.txt
2. c:\prov\barDir

Then, it can't get to c:\prov\fooDir anymore, so it doesn't rename
c:\prov\fooDir\foo2.txt

Is there a more elegant solution than creating an array with the
names, sort the array length descending and rename? I don't trust this
approach because it could happen that it reverts the order of some
files.

Is there a way to traverse a directory leaves-first? (bottom-to-top)

-- 
/(bb|[^b]{2})/ <- The question