Importing URLs of Audio Enclosures

It’s hard to tell what you’re working with from the image, but I’ll assume newline breaks.

<?php

$string = "http://www.podcast.com/track.mp3
2207703
audio/mpeg";

echo "<pre>";
echo $string; // should show multiple rows

To grab the first line, try preg_match:

// now grab the first line

if( preg_match ('/^(.*)$/m', $string, $matches) ){

    echo $matches[0]; // first line is the URL

}