find git repositories that are behind their current remote tracking branch

to_be_pushed.rb

#!/usr/bin/env ruby

pwd = ARGV[0] || '.'
debug = ARGV[1] == '-d'

Dir[File.join(pwd, '**', '.git')].each do |repo|
  repo.gsub!(/\.git$/, '')
  $stderr.puts "in #{repo}" if debug
  if `cd #{repo}; git status`.include?("Your branch is ahead of") 
    puts repo
  end
end