Ruby shell script to show what git branches contain the current release of a heroku app

released-from.rb

#!/usr/bin/env ruby
if ARGV[0].nil?
  puts "List the local branches of a git repository that contain the most recent release of a heroku app."
  puts "usage: released-from heroku-app-name"
  exit
else
  h = `heroku releases -n1 -a#{ARGV[0]}`
  puts h
  parsed = h.scan(/Deploy (.{7}) /).flatten[0]
  unless parsed.nil?
    puts "#{parsed} is on :"
    exec("git branch --contains #{parsed}")
  end
end
# mv ~/Downloads/released-from.rb /usr/local/bin/released-from
# chmod +x /usr/local/bin/released-from

mv ~/Downloads/released-from.rb /usr/local/bin/released-from
chmod +x /usr/local/bin/released-from