Load json gem, installing it first if necessary

load_json.rb

#!/usr/bin/env ruby

def load_json_gem
  if `gem list json -i`.chomp! == "false"
    puts "Installing json gem..."
    `sudo gem install json`
    load_json_gem
  else
    require 'rubygems'
    require 'json'
  end 
end

load_json_gem
body = {:text => "hello"}
puts body.to_json