title: Ruby - Get USB VID/PID from serial port in a cross platform way
body: <p>I'm writing a Ruby gem that will communicate to devices over serial via USB. There are a few different communication formats I need to deal with, the format is determined using a combination of PID/VID values.</p>
  
  <p>I'd like for the gem to be cross platform (Linux/Mac/Windows), but I would settle for just Linux and Mac.</p>
  
  <p>What is the most portable way in Ruby, using the fewest number of gems, to reliably detect USB PID/VID info of a serial port?</p>