php baseurl and <a href tag>

ok so here is my issue.
i have one original blog (WP) that i need to install it to 8 different domain names..everything easy so far, but i want to make it more easy
the blog itself its easy to intsall but it has some links in header.php and footer.php that are like: <a href="www.site.com">.
I don`t want for each blog to go inside these files and edit those urls to point to the different domain on wich it will be installed, i want it to take the domain from wich is accessed automatically..
i guess something like this can be made but i don`t know how:
<a href="<? $_SERVER['HTTP_HOST'] ?>
or something like that..i`m asking cause i`m not too good at coding an dmight ruin everything lol

 

Use
echo $_SERVER['HTTP_HOST'];
or
echo $_SERVER['SERVER_NAME'];

 

and if its like this: www.domain.com/folder/file.php

 

echo $_SERVER['SERVER_NAME'].$_SERVER['PHP_SELF'];

 

Dont forget to put http:// in the start e.g.
<a href="http://<? echo $_SERVER['SERVER_NAME'].$_SERVER['PHP_SELF']; ?>

 

Better yet: $_SERVER['REQUEST_URI'].

Keep in mind that some of the $_SERVER vars are vulnerable to XSS attacks.

 

i just found out that WP has its own code for this:
<?php bloginfo('name'); ?>
then after i can just /folder/file.php normal whitout anything else
thanks guys