putting wordpress template tags into another php codes

http://codex.wordpress.org/Template_Tags/the_permalink

http://codex.wordpress.org/Template_Tags/get_permalink

the_permalink echoes the value, if you need to re-use/store the value, then you need to use get_permalink which simply returns the value, but requires that an ID be given…

See 2 links above..

If you’re trying to generate your site URL then use..

$url = get_bloginfo('url');

Assuming you’re in the loop..

$url = get_permalink( $post->ID );