Portly

Install

Install simply with gem:

gem install portly

Lookup a port

require 'portly'
Portly.lookup 22
#=> [{"service_name"=>"ssh", "port_number"=>22, "transport_protocol"=>"tcp", "description"=>"The Secure Shell (SSH) Protocol", "assignee"=>nil, "contact"=>nil, "registration_date"=>nil, "modification_date"=>nil, "reference"=>"[RFC4251]", "service_code"=>nil, "known_unauthorized_uses"=>nil, "assignment_notes"=>"Defined TXT keys: u=<username> p=<password>"}, {"service_name"=>"ssh", "port_number"=>22, "transport_protocol"=>"udp", "description"=>"The Secure Shell (SSH) Protocol", "assignee"=>nil, "contact"=>nil, "registration_date"=>nil, "modification_date"=>nil, "reference"=>"[RFC4251]", "service_code"=>nil, "known_unauthorized_uses"=>nil, "assignment_notes"=>"Defined TXT keys: u=<username> p=<password>"}, {"service_name"=>"ssh", "port_number"=>22, "transport_protocol"=>"sctp", "description"=>"SSH", "assignee"=>"[Randall_Stewart]", "contact"=>"[Randall_Stewart]", "registration_date"=>nil, "modification_date"=>nil, "reference"=>"[RFC4960]", "service_code"=>nil, "known_unauthorized_uses"=>nil, "assignment_notes"=>"Defined TXT keys: u=<username> p=<password>"}] 

Data Source:

The data is extracted from the CSV file in the data/ directory. This file is collected from the IANA registry here.