Re: Turning a string into a condition
| From: | Matijn Woudt | Date: | Thu, 16 Feb 2012 22:30:19 +0000 |
| Subject: | Re: Turning a string into a condition | ||
| References: | 1 2 3 4 5 6 7 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-316643@lists.php.net to get a copy of this message | ||
On Thu, Feb 16, 2012 at 10:37 PM, Marc Guay <marc.guay@gmail.com> wrote:
>> It shouldn't be that hard to parse this type of expressions.
>
> I appreciate your concern, and will do my best to validate the input,
> but there are two things:
>
> 1) The application will only be used by selected users.
> and
Even selected users can not be trusted, or it could be 'by accident',
though that seems unlikely.
> 2) The range of possibilities are broader than I indicated. They
> would like to be able to enter conditions of all sorts. i.e.
>
> ($x / $y) > 0.5
> (($a+$b+$c) / $d) < .75
>
> etc.
>
> If you have any suggestions on how to increase the security while
> maintaning the flexibility, I'd be happy to hear it.
>
> Marc
A simple recursive PHP parser would work. You can find an example
here[1], though it handles probably more than you would like.
- Matijn
[1] http://aragon-online.net/forums/showthread.php?t=530