find links in a string and replace them with actual html link tags

links.php

<?php
$urls = "yahoo.com Regexes are not a magic wand that you wave at every problem that involves strings. Plus,"
        . " validation of URLs is a solved problem that you do not need to solve yourself. "
        . "google.com You use existing http://maxworth.ca/wp-admin/customize.php?return=%2Fwp-admin%2Fupdate-core.php&autofocus%5Bcontrol%5D=background_image code google.com that has bing.com already "
        . "been https://google.com written, tested and debugged";

function makeUrls($urls) {
    $url_list = preg_split('/[\s]+/', $urls);

    $pattern = '/(?:https?:\/\/)?(?:[a-zA-Z0-9.-]+?\.(?:[a-zA-Z])|\d+\.\d+\.\d+\.\d+)/';
    $newString = '';
    foreach ($url_list as $key => $value) {

        if (preg_match($pattern, $value)) {
        	$url = $value;
        	if(substr($url, 0, 4) != 'http')
        		$url = "http://".$url;
            $newString .= "<a target='_blank' href=" . $url . ">{$value}</a> ";
        } else {
            $newString .= $value . ' ';
        }
    }
    return $newString;
}
echo makeUrls($urls);
?>