From: Carlos <angus@...>
Date: 2001-09-25T20:14:00+09:00
Subject: [ruby-talk:21666] Threads and $SAFE

I'm trying to load some scripts that interact with my main script, but I
don't want them to do unsafe operations, or puts, etc...

First question: according to the Ruby Book, this should work. Why doesn't
it?

Thread.new {
	$SAFE=4
	load("x.rb", true) # I should be able to load wrapped scripts (?)
}.join

$ ruby loader.rb
loader.rb:3:in `load': Insecure operation `load' at level 4 (SecurityError)
        from loader.rb:1:in `join'
        from loader.rb:1

And the second and maybe critical question:

Can I change the $SAFE level in some parts of the script? I want to do
unsafe operations at the loaded script's demand, but only under my control.
Something like that:

def callback(x); puts "called with #{x}"; end
Thread.new {
	$SAFE=4
	callback(1)
}.join

Of course it doesn't work, because `callback' is called in the current
thread. But is there a way to do it? Maybe I can declare some portions of
code as safe, before changing the value of $SAFE (?).