The TextMate command to rename file

gistfile1.rb

#!/usr/bin/env ruby

require "#{ENV['TM_SUPPORT_PATH']}/lib/ui"
require "#{ENV['TM_SUPPORT_PATH']}/lib/textmate"

filename = TextMate::UI.request_string(
  :title => "Rename File",
  :prompt => "To:",
  :default => ENV["TM_FILENAME"]
)
filepath = ENV["TM_FILEPATH"].gsub(ENV["TM_FILENAME"], filename)
File.rename(ENV["TM_FILEPATH"], filepath)
TextMate.rescan_project
TextMate.go_to :file => filepath