With Sinatra you can quickly create your own tiny web-applications in Ruby and write lots of small services.

Problem definition

To upload a text file to a Sinatra web service and have its sorted content returned.

How to upload a file from the command line?

We shall use cURL, a tool and library designed to give you a user-friendly but low-level interface to making HTTP requests. cURL also supports many other protocols related to uploading and downloading files.