Function: Determines whether a PHP ini value is changeable at runtime.

Function: Retrieves the current network ID.

Function: Check or set whether WordPress is in “installation” mode.

Function: Return the HTTP protocol sent by the server.

Function: Copy an object.

Function: Determines whether the current request is for an administrative interface page.

Function: Determines whether the current request is for a site’s administrative interface.

Function: Determines whether the current request is for the network administrative interface.

Function: Determines whether the current request is for a user admin screen.

Function: If Multisite is enabled.

Function: Retrieve the current site ID.

Function: Set internal encoding.

Function: Attempt an early load of translations.

Function: Add magic quotes to `$_GET`, `$_POST`, `$_COOKIE`, and `$_SERVER`.

Function: Runs just before PHP shuts down execution.

Function: Load the database class file and instantiate the `$wpdb` global.

Function: Set the database table prefix and the format specifiers for database table columns.

Function: Toggle `$_wp_using_ext_object_cache` on and off without directly touching global.

Function: Fix `$_SERVER` variables for various setups.

Function: Start the WordPress object cache.

Function: Check for the required PHP version, and the MySQL extension or a database drop-in.

Function: Redirect to the installer if WordPress is not installed.

Function: Don’t load all of WordPress when handling a favicon.ico request.

Function: Retrieve an array of must-use plugin files.

Function: Die with a maintenance message when conditions are met.

Function: Retrieve an array of active and valid plugin files.