截取一行中的部份字串

pommy

[code:1]Powered by <a href="http://www.phpbb.com/" target="_phpbb" class="copyright">phpBB</a> 2.0.3 © 2001 phpBB Group<br /><br>[/code:1]

請問如何截取這行中 http://www.phpbb.com/ 這個字串? 謝謝!

javalee

[code:1]grep -o 'http://[a-z.]*/'[/code:1]