Wrap all methods with a specific code

method-wrap.rb

class Foo
  def self.method_added(m)
    t = Thread.current

    unless t[:_hook]
      t[:_hook] = true
      begin
        alias_method "_#{m}", m

        class_eval %Q{def #{m}(*a, &b)
          bak = Process.euid
          begin
            _#{m}(*a, &b)
          ensure
            Process.euid = bak
          end
        end}
      ensure
        t[:_hook] = false
      end
    end
  end

  def x(a)
    puts a
  end
end

Foo.new.x 1

2 questions that I don't understand.

1. what is thread for?
2. def #{m} (_a)
   bak...
   begin
   _#{m} (_a)
   ensure
   end
   end

do we really need &b?

oh. i'm jarodzz in ruby-talk.

thanks again for this nice solution.

got it.
the (*a, &b) is for block args.