Ruby Command in Grunt

JavaScript
3

Probably.

Say you have two files:

test.js

var process = require('child_process');
process.exec('ruby hello.rb',function (err,stdout,stderr) {
  if (err) {
    console.log("\n"+stderr);
  } else {
    console.log(stdout);
  }
});

hello.rb

puts "Hello"

Run:

$ node test.js
=> Hello

Play around with that and you should be able to do what you are attempting.
Docs: https://nodejs.org/api/child_process.html
Ref: http://stackoverflow.com/questions/1880198/how-to-execute-shell-command-in-javascript