regex in php, which chars to escape in this pattern?

bitterclarence

Hello, i'm still quite new to using regex in php and i've got stuck on something that i think should be pretty styraightforward.

I'm trying to transform a line of XML like this...

<Dload url=\"www.mysite.com/file.zip\"><![CDATA[Click to download the zipped file]]></Dload>

into a line of html like this...

<p><a href="www.mysite.com/file.zip">Click to download the zipped file</a></p>

Here's my attempt (the pattern doesn't match), i'm unclear about how i should be escaping characters in the pattern and replacement strings..

$pattern="<Dload url=\"([^\"]*)\"><![CDATA\[([^\]]*)]]></Dload>"; // format dload links 
	$replacement="<p><a href=\"\\\1\">\\\2</a></p>";
	$datastring = ereg_replace ($pattern, $replacement, $datastring);

can anyone give me a hand?

xblue

you need to escape all characters that would have a special meaning inside a meaning (in your example particularly the square brackets) if you want to match them literally.

they are listed here, you just need to scroll down a little
http://www.php.net/manual/en/pcre.pattern.syntax.php

bitterclarence

THanks for the reply. I was thinking that it had to do with the square brackets

$pattern="<Dload url=\"([^\"]*)\"><!\[CDATA[([^\]]*)\]\]></Dload>";

I thought this would be the correct way to escape the pattern string, but this doesn't work either.. do you know what i'm doing wrong?

xblue

I'd think the [ right after CDATA would need to be escaped, too.

You didn't say in which way it failed (compilition error? no matches?), however this might be helpful for debugging.