snippet.rb

#!/usr/bin/ruby

files = {}
Dir.glob('**/*').each do |file|
  basename = File.basename(file).downcase
  if File.file?(file)
    files[basename] ||= []
    files[basename] << file
  end
end

duplicates = files.values.select { |v| v.size > 1 }

duplicates.each do |files|
  files.each do |file|
    puts %Q{"#{file}" [#{File.size(file)}]}
  end
  puts
end