consolidate two git repos

consolidate_repos.rb

#!/usr/bin/env ruby
# -*- coding: utf-8; ruby -*-
# http://d.hatena.ne.jp/okinaka/20111010/1318211550

require 'shellwords'

def main
  old         = File.expand_path(ARGV[0])
  new         = File.expand_path(ARGV[1])
  branch_name = Time.now.to_i.to_s

  Dir.chdir(old) do
    git('fetch %s refs/heads/master:refs/heads/%s' % [Shellwords.escape(new), branch_name])
    git('checkout %s' % branch_name)
    git('rebase master')
    git('checkout master')
    git('merge %s' % branch_name)
    git('branch -d %s' % branch_name)
  end
end

def git(cmd)
  cmd = 'git ' + cmd

  puts   cmd
  system cmd
end

main