Converting relative URLs to absolute URLs with regex

Today I was working on an app in which the menu had to be built using a HTML editor. And sure enough, half of the URLs that were supposed to be absolute were not. Luckily, it's fairly easy to fix that with a regex search/replace.

Here's the regex to search for:


This look for any string starting with href=", followed by any string that does NOT start with 'http'.

Then just replace all occurances with:


And Bob's your uncle!

Pro tip: a great Mac app to test your regular expressions with is Patterns.