File Directory Ruby

def delete_all(dir)
  Dir.foreach(dir) do |e|
    # Don't bother with . and ..
    next if [".",".."].include? e
    fullname = dir + File::Separator + e
    if FileTest::directory?(fullname)
      delete_all(fullname)
    else
      File.delete(fullname)
    end
  end
  Dir.delete(dir)
end
delete_all("dir1")   # Remove dir1 and everything under it!