<?php
$string = '<img src="http://s...content-available-to-author-only...k.com/img.jpg"> http://s...content-available-to-author-only...k.com
http://w...content-available-to-author-only...e.com
http://e...content-available-to-author-only...e.com/
<a href="http://www.google.com">Google</a>
https://w...content-available-to-author-only...e.com/seconday/somepage#hashes?parameters
https://w...content-available-to-author-only...e.com/seconday/
<link rel="stylesheet" type="text/css" href="http://w...content-available-to-author-only...n.com/style.css" />
http://w...content-available-to-author-only...e.com/seconday
<script type="text/javascript" src="http://d...content-available-to-author-only...n.com/includes/javscript.js"></script>
http://e...content-available-to-author-only...e.com/seconday
http://e...content-available-to-author-only...e.com/seconday/';
$string = preg_replace('~(?<!(?:"|\'|=))((?:http(?:s)?://)(?:www\.)?[-A-Z0-9.]+(?:\.com)[-A-Z0-9_./]?(?:[-A-Z0-9#?/]+)?)~i', '<a href="$1">$1</a>', $string);
print $string;
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