Question

I’m looking for the string (or strings – there might be many occurrences), between the following:

<!--## and ##-->

Example: from the input <!--##HELLO##--> I need to match HELLO.

What would be the regex?

Answer 1

The regex

<!--##(.*?)##-->

Will store the text in the first group. Be sure to set the option that lets the . match newline (/s below)

For php preg this becomes

if (preg_match('/<!--##(.*?)##-->/s', $subject, $regs)) {
    $result = $regs[1];
} else {
    $result = "";
}