preg_replace... "unknown modifier"

[craigm]

Ok so I want to add some url's to user input such that they can make full fledged hyperlinks. But I want them to be able to use a simplified code that doesn't get stripped by htmlspecialchars.
It would look like this: [link="someurl"]link text[/link]

here's my code so far

<?php
$mystring="[link=\"someurl\"]link text[/link]";
$myhtml=addbackhtml($mystring);
print ($myhtml);

function addbackhtml($mystring){
	$nonhtml_link="/([link=\")(.*)(\"\])/(.*)(\[/link\])/";
	$html_link="<a href=\"$2\">$4/a>";
	$mystring= preg_replace($nonhtml_link,$html_link,$mystring);

return $mystring;
}		

?>

I get : Warning: Unknown modifier '(' in addbackhtml.php on line X

X being the line that contains the preg_replace.

Thanks in advance

[craigm]

Well after some more head scratching, I've made it work. If anyone has any suggestions on how I can improve the code, that's cool too.

Basically, there were tow characters I forgot to escape a "/" and a "[".

Here's what I came up with:

<?php
$mystring="[ link =\"http://www.phpbuilder.com\"]link text[/link]";
$myhtml=addbackhtml($mystring);
print ($myhtml);

function addbackhtml($mystring){
	$nonhtml_link="/(\[ *link *=)(\".*\")( *\])(.*)(\[\/link\])/";
	$html_link="<a href=$2>$4</a>";
	$mystring= preg_replace($nonhtml_link,$html_link,$mystring);

return $mystring;
}

?>[/QUOTE]

[_e_r_k]

There is absolutely nothing wrong with your code, but this is how I would have done it..

$nonhtml_link = "/\\[ *link *=\\"([^\\"]*)\\"\\](.*?)\\[\\/link\\]/";
$html_link="<a href=\\"\\\\1\\">\\\\2</a>";