NYCPHP Meetup

[max goldberg]

That actually wouldn't work, in order to do eval() you must pass it a 
valid piece of code, so at runtime your code would return a parse error 
as it would be the same as a line of code that said 'this string = $one 
and that is it', where as '\\$string = $one;' would parse.

Earlier I gave the answer:

$one = '1';
$two = '$one';
eval("\\$result = \\"$two\\";");
echo $result;

Which would work fine, but you are very correct about the safety and it 
is a bad idea to eval anything coming in from user input without a huge 
load of data integrity checking.

-Max

Analysis & Solutions wrote:
> On Thu, Oct 17, 2002 at 04:24:28PM -0400, Adam Fields wrote:
> 
>>On Thu, Oct 17, 2002 at 04:01:52PM -0400, Analysis & Solutions wrote:
>>
>>That is also not my question. I don't want to know how to assign a
>>string such that variable interpolation happens. I want to know how to
>>take an existing string and perform variable interpolation on it.
> 
> 
> Oh.  I didn't understand your question.  Guess I was too busy working on 
> other things to really pay attention to the whole thread.  Max was on 
> target with eval().  So, continuing with my example...
> 
>   $one = 1;
>   $two = 'this string = $one and that is it';
>   $three = eval($two);
>   echo $three;
>   [results:  this string = 1 and that is it]
> 
> Now, BE CAREFUL about using eval().  You could do some really nasty things 
> if the incoming string is corrupted by nasty persons.  Please read the PHP 
> manual about eval() to make sure you're being safe.
> 
> --Dan
>