dolphin/single-functions/extract-email-links.php

<?php
/**
 *  dolphin. Collection of useful PHP skeletons.
 *  Copyright (C) 2019  Johannes 'Banana' Keßler
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the COMMON DEVELOPMENT AND DISTRIBUTION LICENSE
 *
 * You should have received a copy of the
 * COMMON DEVELOPMENT AND DISTRIBUTION LICENSE (CDDL) Version 1.0
 * along with this program.  If not, see http://www.sun.com/cddl/cddl.html
 */

/**
 * extract from given string (was email body) any links we want to add
 * should be in the right format
 * return an array with links and the infos about them
 *
 * @param string $string
 * @return array $ret
 */
static function extractEmailLinks($string) {
    $ret = array();

    #this matches a valid URL. An URL with | is still valid...
    $urlpattern  = '#(?i)\b((?:[a-z][\w-]+:(?:/{1,3}|[a-z0-9%])|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}/)(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s`!()\[\]{};:\'".,<>?«»“”‘’]))#';

    preg_match_all($urlpattern, $string, $matches);
    if(isset($matches[0]) && !empty($matches[0])) {
        foreach($matches[0] as $match) {
            $ret[md5($match)] = $match;
        }
    }


    return $ret;
}