Can I get a "base URL" in WordPress within a template file?

Usually in my PHP apps I have a base URL setup so I can do things like this

<a href="<?php echo BASE_URL; ?>tom/jones">Tom</a>

Then I can move my site from development to production and swap it easily and have the change go site wide (and it seems more reliable than <base href="" />.

I'm doing up a WordPress开发者_运维百科 theme, and I am wondering, does WordPress have anything like this built in, or do I need to redefine my own?

I can see ABSPATH, but that is the absolute file path in the file system, not something from the document root.

get_bloginfo('wpurl'); would be the preferred method of getting the base url of your WordPress installation. This always returns the absolute base url for the install where as get_bloginfo('url'); is for the actual blog address of your WordPress install.

Yes, you can use get_bloginfo('url') just like that or define a constant...

define('BASE_URL', get_bloginfo('url'));

If you are working on a template and want the URL fragment to that theme folder, use...

bloginfo('template_directory'); 

You can try using

<?php echo home_url(); ?>

By using this can get site url like www.xyz.com

<?php echo home_url('/contact'); ?>

By using this syntax you will get url like www.xyz.com/contact

Yes you can get "base URL" with a simple function.

<?php echo get_bloginfo('url') ?>

after that with / you can reach to any page just type the page name.

You can use the built in wordpress function site_url() which retrieves the URL for the current site.

Take a look at site_url for more details.

EX:

<a href="<?php echo site_url('tom/jones'); ?>">Tom</a>