From: Erik Veenstra <pan@...>
Date: 2006-02-09T03:23:23+09:00
Subject: Re: Sandboxing eval'd code

class String
  def de_inspect
    Thread.new do
      $SAFE     = 4

      de_inspect_unsafe
    end.value
  end

  def de_inspect_unsafe # But fast...
    eval(self, Module.new.module_eval{binding})
  end

  def evil_eval # Don't use it !!!
    eval(self)
  end
end

def foo ; p [self, 1] ; end

foo

"def foo ; p [self, 2] ; end".evil_eval

foo

"def foo ; p [self, 3] ; end".de_inspect_unsafe

foo

"def foo ; p [self, 4] ; end".de_inspect # Will fail...

foo