gistfile1.txt

<?php 

	$string = "Dear students,
Mirjan sent a link to her Amazing presentation. So those of you who have are familiar with Evernote can revisit it here: 
https://www.evernote.com/shard/s65/sh/e180fbf3-9c20-4fe5-85e2-939474e7ca1d/1f55bd659209cbd71fcf13ee83921140
The rest shall have to wait patiently for me to turn it into a little less gigantic pdf.
Cheeerio!";
$pattern = '/(http|https)\:\/\/[a-z0-9\-\.]+\.[a-z]{2,3}(\/\S*)?/im';

$match = array();

preg_match($pattern, $string, $match);

echo $match[0] . "\n";

foreach($match as $m){
//	echo $m . "\n"; 
}

?>

$match[0] will be https://www.evernote.com/shard/s65/sh/e180fbf3-9c20-4fe5-85e2-939474e7ca1d/1f55bd659209cbd71fcf13ee83921140 on my php.

Regardless of linebreaks.