From: "Morris, Chris" <chris.morris@...>
Date: 2002-06-05T21:27:29+09:00
Subject: RE: How safe is $SAFE=4?

> [shoujoai@lina safe]$ cat myeval.rb 
> def safeEval(expr)
>     result = nil
>     Thread::start {
>         $SAFE = 4
>         result = eval expr
>     }.join
>     result
> end
> 
> loop {
>     print 'Enter expression: '
>     expr = gets
>     break if !expr
>     puts safeEval(expr)
> }
> [shoujoai@lina safe]$ ruby myeval.rb
> Enter expression: 1+1
> 2

Huh - I tweaked the above to check expr.tainted? and it is true when it's
evaled -- according to http://www.rubycentral.com/book/taint.html at $SAFE
>= 1, tainted strings cannot be evaled. Why does this script work, eval-ing
1+1?

Chris