Find all empty directories in an svn checkout. Output has escaped spaces in file paths.

find-empty-dir-in-svn.rb

require 'find'

dir_to_scan = '.'
dir_to_scan = ARGV[0] if ARGV.count == 1

dirs = []

# First collect all directories, but ignore anything with .svn in it
Find.find( dir_to_scan ) do |entry|
    next if entry =~ /\.svn/
    next if not File.directory?(entry)
    dirs << entry
end

# Sort directory by slashes and then by string length so that the deepest
# directories will come first
dirs.sort! do |a,b|
    aa = a.count('/');
    bb = b.count('/');
    next b.length <=> a.length if aa == bb
    bb <=> aa
end

dirs_count = {}

# fetch the dirs and count number of subdirs, excluding .svn again
dirs.each do |dir|
    dirs_count[dir] =
        Dir.entries(dir).collect { |e|
            case e
            when '.svn'
                nil
            when '.'
                nil
            when '..'
                nil
            else
                e
            end
        }.compact.count
end

last_dir = nil
empty_on_current_level = 0

dirs_count.each do |dir,count|

    if last_dir == nil
        last_dir = dir
        next
    end

    # is the last entry on the same level as the current one and are both empty
    reset_empty = false
    if last_dir.gsub(/\/[^\/]+$/, '') == dir.gsub(/\/[^\/]+$/, '')
        if dirs_count[last_dir] == 0 and dirs_count[dir] == 0
            empty_on_current_level += 1
        end
    else
        reset_empty = true
    end

    # is the directory before a direct child and is it empty?
    if last_dir.length > dir.length and last_dir.index(dir) == 0 and last_dir[ (dir.length)..-1 ].index('/') and dirs_count[last_dir] == 0
        # then assume we would delete that dir and decrease the count on the
        # current directory
        dirs_count[dir] -= (1 + empty_on_current_level)
    end

    empty_on_current_level = 0 if reset_empty

    last_dir = dir
end

dirs_count.each do |dir,count|
    puts dir.gsub(' ', '\\ ') if count == 0
end

On Line #76, added support for escaping spaces in directory names. Its needed to redirect output directly to commands like xargs svn rm