Multisite (category)
| get_blog_details() | Gets all data of the specified blog from the blogs and blog options tables. |
| get_current_blog_id() | Retrieve the current site (blog) ID. |
| get_dirsize() | Gets the size of a directory in bytes. The result is cached to a transient option (or object cache). |
| get_id_from_blogname() | Gets the site (blog) ID by the specified slug: subdomain or directory name. |
| get_main_site_id() | Gets the ID of the main site of the network. |
| get_site_meta() | Gets the value of the site's meta-field in a multisite network. Also allows retrieving all meta-fields. |
| get_sites() | Retrieves a list of sites in the form of array in the current network matching requested arguments. |
| grant_super_admin() | Sets the specified user as a super administrator. |
| is_blog_admin() | Checks whether the current page—the current request—is a page in the admin area of an individual site in a WordPress MU network. Conditional tag. |
| is_main_site() | Determines whether the current/specified site is the main site of the network (MU build). |
| is_multisite() | Checks whether multisite support is enabled on the site. Conditional tag. |
| is_network_admin() | Checks whether the current page is a page in the admin section "Network Admin" of the multisite. For example /wp-admin/network/. Conditional tag. |
| is_user_admin() | Checks if the requested page is a user page in the admin area, in a multisite network. For example: /wp-admin/user/ or /wp-admin/user/profile.php. Conditional tag. |
| network_admin_url() | Retrieves the URL to the admin panel for the network — many sites management (not for a single blog of the network): |
| network_home_url() | Gets the URL of the homepage of the main site in the current network of sites (for MU installation). |
| recurse_dirsize() | Recursively gets the size of a directory in bytes. That is, you can specify the parent folder and get its full size: including nested folders. |
| restore_current_blog() | Returns global variables to their previous state after switching to another site using switch_to_blog(). |
| switch_to_blog() | Switches to the specified blog in a multisite system. |
| update_user_status() | Updates the user status in the database. For multisites. |
Options
| add_network_option() | Adds a network setting. Used in a multisite setup. |
| get_network_option() | Gets the value of the specified network option (the main site in a multisite network). |
| get_site_option() | Gets the specified option of the main site of the current network. |
| get_site_transient() | Gets the value of the temporary option of the main site in the network. |
| update_site_option() | Updates or adds the specified option for the current site (current blog network). For multisite networks. |
Users
| delete_user_option() | Deletes user metadata on a site-wide or network-wide basis. |
| get_user_option() | Gets the specified user option. The option will relate to the site user in the network (for multisite installations) or just to the user. |
| update_user_option() | Updates the user option (meta-field). Designed for MU mode. A wrapper for update_user_meta(), only adds the database prefix to the meta-field name. |