Securely erase files and folders recursively in Linux

This ruby script will securely erase files and folders recursively in Linux. You may want to add a action to run this script to the context menu of Nautilus using nautilus-actions.

# 
# Shreds files and folders recursively. Code released under MIT license.
 
NUMBER_OF_PASSES = 20
def shred_files_and_folders(path)
  if File.directory?(path)
    files =  Dir.entries(path)
    files.delete_if {|x| x == "." or  x == ".." }
    files.each do |f|
      if File.directory?(path + '/' + f)
        shred_files_and_folders(path + '/' + f)
      else
        puts ` shred -v -z -u -n#{NUMBER_OF_PASSES} #{path + '/' + f}`
      end
    end
    Dir.rmdir(path)
  else
    puts ` shred -v -z -u -n#{NUMBER_OF_PASSES} #{path}`
  end
end

ARGV.each do |path|
  shred_files_and_folders(path)
end