gistfile1.rb

arg = `echo $COUNT_CALLS_TO`

KLASS, METHOD = *arg.split('#').map(&:strip)

module MethodCounter
  module ClassMethods
    @@method_times_run_var = 0
    def method_times_called
      @@method_times_run_var
    end
    def method_times_called=(inc)
      @@method_times_run_var = inc
    end
  end

  def self.included(base)
    base.extend ClassMethods
    base.class_eval do
      alias_method "original_#{METHOD}", METHOD
      define_method METHOD do
        self.class.method_times_called += 1
        send "original_#{METHOD}"
      end
    end
  end
end

begin
  Module.const_get(KLASS).send :include, MethodCounter
rescue NameError
  class Class
    alias_method :original_new, :new
    def new(*args, &block)
      include MethodCounter if self.name == KLASS && !self.include?(MethodCounter)
      original_new *args, &block
    end
  end
end

at_exit do
  puts "#{KLASS}##{METHOD} called #{Module.const_get(KLASS).method_times_called} times."
end