upload.ru

app = proc do |env|
  response  = Rack::Response.new
  request   = Rack::Request.new(env)
  info      = request.params['info']

  if info and info[:tempfile]
    response['Content-Type'] = info[:type]
    response.body            = info[:tempfile].readlines.sort
  else
    response['Content-Type'] = 'text/plain'
    response.status          = 400
    response.write "info parameter must be a file uplad"
  end

  response.finish
end

run app

Usage:

$ rackup upload.ru

File alpha.txt contains:

zebra
yen
xmas
birthday
cat
apple
pune
mumbai
nashville

Client:

$ curl -F "info=@alpha.txt" localhost:9292

Result:

apple
birthday
cat
mumbai
nashville
pune
xmas
yen
zebra

Very useful thxs