dead_branches.rb

require 'rubygems'
require 'grit'
require 'active_support'
include Grit
merged_branches = `git branch -a --merged`.split("\n").collect(&:strip) - ["* master"]
repo = Repo.new(ARGV[0])
merged_branches.each do |branch|
  begin
    last_commit = repo.commits(branch).first
    last_time = Time.parse last_commit.to_hash['committed_date']
    committer =  last_commit.to_hash['committer']
    if last_time < 30.days.ago
      puts "#{branch.sub("remotes/origin/", "")}:\t#{last_time.strftime("%m/%d/%Y")}\t#{committer['name']} #{committer['email']}"
    end
  rescue
    puts "Failure on branch: #{branch}"
  end
end