#!/usr/bin/env ruby

submodule_status = `git submodule status`
updated_submodules = []

submodule_status.each_line do |line|
  # Submodules that are not updated start with a + in the submodule status
  # output.

  if line.match(/^\+/)
    # The second word is the submodule directory.
    updated_submodules << line.split(" ")[1]
  end
end

if updated_submodules.length > 0
  puts "The following git submodules are out of date:"
  updated_submodules.each do |submodule|
    puts "\t#{submodule}"
  end
  puts
  puts "Suggest: 'git submodule update'."
end