php-regexp/search.php

<?php

//include 'kint.phar';

function search($pattern, $str) {
    if (preg_match_all("/(?:[^\.]*)($pattern)(?:[^\.]*)/i", $str, $matches, PREG_PATTERN_ORDER) !== false) {
        //d($matches);
        foreach ($matches[0] as $index => $value) {
            $pattern_value = $matches[1][$index];
            echo str_replace($pattern_value, "<span style=\"background-color: yellow\">$pattern_value</span>", $value), "<br><br>";
        }
    }
}


if (empty($pattern = $_GET['q'])) {
    return;
}


$str = file_get_contents('regexp.txt');

search($pattern, $str);