Find the Admin URL in WordPress 3.0

The other day I was looking for a way to get the URL to the installed WordPress admin folder. I was almost certain that I would have to ‘construct’ this URL manually. This wasn’t a problem I had done similar tasks many times before.

But to my pleasant surprise I found a nifty little function called get_admin_url(), which I didn’t know existed. This is probably as it is a new addition to WordPress 3.0. The function can be found in the /wp-includes/link-template.php file at line number 1950. You can see the full source code here.

Looking at the core code it is obvious that this function was written with a more general purpose in mind. In fact it returns the WordPress admin URL of multi-site blog with a specific ID. If you don’t specify a particular ID then it returns the current blog admin URL.

Interestingly, there is another closely related function called admin_url() which returns the admin URL of the current blog only. The difference between the two is that you can’t specify a blog ID with this function.

If you only need to get the admin URL of the current blog (as I did) then you can use either function with no parameters, and they will both return exactly the same result. It’s just a matter of preference.

Looking through the /wp-includes/link-template.php file I noticed that there were a few other new functions added to WorPress 3.0 for returning WordPress links.

Here is a quick summary (including links to the source code) of all the new link related functions in link-template.php:

• get_post_permalink() – Retrieve the permalink for a post with a custom post type.
• the_feed_link() – Display the permalink for the feed type.
• get_search_link() – Retrieve permalink for search.
• adjacent_posts_rel_link_wp_head() – Display relational links for the posts adjacent to the current post for single post pages.
• home_url() – Retrieve the home url for the current site.
• get_home_url() – Retrieve the home url for a given site.
• get_site_url() – Retrieve the site url for a given site.
• get_admin_url() – Retrieve the url to the admin area for a given site.
• network_site_url() – Retrieve the site url for the current network.
• network_home_url() – Retrieve the home url for the current network.
• network_admin_url() – Retrieve the url to the admin area for the network.
• wp_get_shortlink() – Return a shortlink for a post, page, attachment, or blog.
• the_shortlink() – Display the Short Link for a Post.