require 'fileutils'
dir = './word_folder'
Dir.entries(dir)[2..-1].each do |file|
  p src = File.join(dir, file)
  puts trg = file.gsub!(/\n/,'').gsub!(' ','_')
  puts trg = file.gsub(/\n/,'')
  trg = File.join(dir, trg)
  FileUtils.mv(src, trg ,verbose: true)
end