From: Robert Dober <robert.dober@...>
Date: 2008-04-20T23:31:09+09:00
Subject: Re: Executing code in a variable

On Sun, Apr 20, 2008 at 3:53 PM, David A. Black <dblack@rubypal.com> wrote:

As David I am not sure that instance_eval is safer than eval. As the
following example shows a save eval can be done by deleting all
dangerous methods before evalling:

module Kernel
  class << self
    methods.each do |m|
      next if /^__/ === m
      Object::send :remove_method, m
    end
  end
  instance_methods.each do |m|
    next if /^__/ === m
    Object::send :remove_method, m
    remove_method m
  end
end


eval %<system "ls -l">

Now this might not often be very useful though as we do not have a
sandbox or to put it better, it is much work to get out
of the sandbox again as we have to redefine all methods again (well I
did not safe them in the first place here). Furthermore my sandbox is
empty!!!

Is there an easy way to do this?

Cheers
Robert
-- 
http://ruby-smalltalk.blogspot.com/

---
Whereof one cannot speak, thereof one must be silent.
Ludwig Wittgenstein