From: Bill Kelly <billk@...>
Date: 2005-04-23T00:41:30+09:00
Subject: Re: [QUIZ] HighLine (#29)

From: "James Edward Gray II" <james@grayproductions.net>
>
> >> num = eval "0b#{ ask( 'Enter a binary number.',
> >>                       String, :validate => /^[01_]+$/ ) }"
> >
> > Do not ever do that.
> >
> > irb(main):004:0> Integer("0b1011")
> > => 11
> > irb(main):005:0> "1011".to_i(2)
> > => 11
> >
> > irb(main):006:0> "foo\nbar" =~ /^foo$/
> > => 0
> 
> I'm not exactly sure what you're trying to show here.  Even 0 would be 
> a fine binary number.  However, the point was that I have created a 
> safe eval() because ask() should not return anything that doesn't 
> validate.

I think he meant along the lines of:

irb --simple-prompt
>> p "looks ok!" if "01010\nsystem('rm -rf /')" =~ /^[01_]+$/
"looks ok!"


Regards,

Bill