PHP: Extract Urls from String

extract_urls_from_string.php

<?php
function getUrls($string) {
  //adapted from: https://stackoverflow.com/questions/11588542/get-all-urls-in-a-string-with-php
  $regex = '/https?\:\/\/[^\" \n]+/i';
  preg_match_all($regex, $string, $matches);
	//note below that we use $matches[0], this is because we have an array of arrays
	foreach ($matches[0] as $url) {
		$s1 = substr($url, 0, strlen($url)-2);
		$s2 = '<a href="' . $s1 . '">' . $s1 . '</a>';
		echo "$s2<br />\n";
	}
}

$s = "Also see: 
<http://www.nature.com/news/2008/081120/full/news.2008.1246.html>
<http://www.physicsforums.com/showthread.php?t=273814>

This is a string with embedded urls. Separate out just the urls and display them.";

getUrls($s);
?>