Perl expression to extract URL from text

[meman1188]

I'm looking for a perl expression to extract urls from text. The more flexible it is the better.

 

For example, it would be nice if it could find all of these:

http://www.yahoo.com

yahoo.com

www.yahoo.com/mypage/

 

Thanks so much for the help!

[effigy]

<pre>
<?php

$data = <<<DATA
http://www.yahoo.com
yahoo.com
www.yahoo.com/mypage/
DATA;

echo preg_replace_callback('%
	### Protocol or start.
	(?:
		https?://
		|
		www\.
		|
		### Add to as needed.
		\w+\.(?:com|net|org)
	)
	### Body.
	(?>
		### Gobble all non-space
		\S+
		### Avoid ending punctuation.
		(?<!\p{P})
	)?
%x',
create_function(
	'$url',
	'$url = $url[0]; if (substr($url, 0, 7) != "http://") { $url = "http://" . $url; } return "<a href=\"$url\">$url</a>";'
),
$data
);	

?>
</pre>