Using PHP Code Inside a Regular Expresion

[ucahg]

How would I add the functionality to a PHP script so if it is parsing text and comes across this:

...other text...
[PHP]
echo 'Hello World';
[/PHP]
...othertext...

that it will show up as

...other text...
Hello World
... other text ...

So that the PHP code is executed. How would I do this? I'm quite sure it is possible, because I execute code in my regexps all the time, but I'm not quite sure how to do this.

(Please answer with preg_replace, not ereg, thanks)

[redemption]

you can use eval()... as for extracting the code, i can't help cos i'm not good at regexp, esp. not PCRE

[DR_LaRRY_PEpPeR]

be VERY VERY careful using eval()! if it's your code, fine. but don't trust what the user enters. that said, try this:

$txt = preg_replace('#\[ php](.+?)\[/php]#eis', 'eval_stuff("$1")', $txt);


function eval_stuff($txt)
{
	// This fixes any single quotes that get
	// messed up being passed to this function
	$txt = str_replace("\'", "'", $txt);

	ob_start();
	eval($txt);
	$output = ob_get_contents();
	ob_end_clean();

	return $output;
}

if your version of PHP is less than 4.0.4, replace $1 with \1. BTW, the ob_xxx stuff makes any echo 'blah'; code's output be returned rather than echo'ed right at that point.