Deleting empty directories

ruby-talk
1

dblack@wobblini.net wrote:

Hi --

[snip]

Anyway, the need has arisen to delete empty directory heirarchies (rsync will delete the files but not the directories because of the .svn subdirs). What I've done so far is this:

require 'fileutils'

def empty_dirs
   @current.collect do |f|
     f if (File.directory?(f) && Dir.glob("#{f}/*").empty?)
   end.compact
end

def remove_empty_dirs
   while not empty_dirs.empty?
     empty_dirs.each {|d| FileUtils.rm_rf(d)}
   end
end

[snip..asking for a better way]

You're currently using collect plus compact, but you can actually just
use select. (That's not a general equivalence, but in this case it
applies.)

  @current.select do |f|
    File.directory?(f) && Dir["#{f}/*"].empty?
  end

I'd be inclined to break things out a little. (Untested code follows
-- please test on expendable data :slight_smile:

  require 'fileutils'

  def dirs
    @current.select {|f| File.dir?(f) }
  end

  def empty_dirs
    dirs.select {|d| Dir["#{d}/*"].empty? }
  end

  def non_empty_dirs
    dirs - empty_dirs
  end

  def remove_empty_dirs
    non_empty_dirs.each {|d| FileUtils.rm_rf(d) }
  end

Hello,

Excellent! David, thanks very much. The extra reduction of tasks is exactly what I was looking for (it certainly is a skill that I am having difficulty mastering).

I changed the remove_empty_dirs to a) remove the empty, not non-empty, dirs (! :o), and b) modify the @current file list:

   def remove_empty_dirs
     until empty_dirs.empty?
       empty_dirs.each do |d|
         @current.delete(d)
         FileUtils.rm_rf(d)
       end
     end
   end

Again, thanks very much.

cheers,

paulv

···

On Wed, 29 Aug 2007, Paul van Delst wrote: