Regex to replace relative link with root relative link
I have a string of text that contains html with all different types of links (relative, absolute, root-relative). I need a regex that can be executed by PHP's preg_replace to replace all relative links with root-relative links, without touching any of the other links. I have the root path already. Replaced links: <tag ... href="path/to_file.ext" ... > ---> <tag ... href="/basepath/path/to_file.ext" ... > <tag ... href="path/to_file.ext" ... /> ---> <tag ... href="/basepath/path/to_file.ext" ... /> Untouched links: <tag ... href="/any/path" ... > <tag ... href="/any/path" ... /> <tag ... href=