Sorting file lines with rackup and curl

gistfile1.rb

# Alpha.txt is supposed to be a text file with multiple lines

# my_sort_file.rb
class MySortFile
  def call(env)
    req = Rack::Request.new(env)
    initial_file = req.params['file']

    Rack::Response.new.finish do |res|
      res['Content-Type'] = 'text/plain'
      res.status = 200
      if(req.params['file'].class==NilClass)
        res.write("Sorry the file does not exist.\n")
      else
        initial_file.split(/\n/).sort.each do |word|
          res.write(word.chomp<<"\n")
        end
      end
    end
  end
end

# config.ru
require './my_sort_file'
run MySortFile.new

# To use it:
# rackup confi.ru in a Terminal
# Then in another Terminal:
# curl --data-urlencode [email protected]  localhost:9292