Find commented code in Ruby

find_commented_code.arb

#!/usr/bin/env ruby
ARGV.each do |filename|
  fileobject = File.new(filename, "r")
  next if fileobject.nil?

  occurences = 0
  lines = fileobject.readlines
  lines.each do |line|
    next unless line.match(/\A *#.+\n/)

    if line.match(/.*[print|puts] ["'].*["']\n/)
      occurences+=1
      next
    end

    line = line.gsub(/\n/,"")
    line = line.sub(/\A *# */," ")

    begin
      eval(line)
    rescue SyntaxError => e
      occurences+=1 if e.message.match(/.*unexpected end.*|.*void.*/)
      next
    rescue
      occurences+=1
      next
    end

    next if line.match(/ *#.*/) # double comments
    occurences+=1
  end

  next if occurences == 0

  percentage = (occurences/Float(lines.count)).truncate(4) * 100
  next if percentage < 10
  pp "#{fileobject.path} has ~#{occurences}/#{lines.count}(#{percentage}%) lines with commented code"
  fileobject.close()
  local_variables.each { |e| eval("#{e} = nil") }
end

Quick disclaimer, this script is by no means exhaustive!

You can run it with find */ -name *.rb -type f | xargs ruby ./find_commented_code.arb