wp-content/plugins/mu-plugins
In WordPress, the directory known as wp-content/plugins/mu-plugins is designated for Must-Use Plugins (MUs). Here's a detailed overview:
What Are Must-Use Plugins?
Must-Use Plugins (MUs) are a special type of plugin in WordPress that automatically activate for all sites on a multisite network. Unlike regular plugins, MUs:
- Are not listed in the regular plugin management interface.
- Do not show up in the list of active plugins.
- Cannot be deactivated through the WordPress admin.
- Run without the user having the ability to disable them.
Location and Structure
The wp-content/plugins/mu-plugins directory:
- Is located within the
wp-content directory, which contains all user-modifiable files for a WordPress installation.
- Does not exist by default; it must be created manually or by an installation script.
- Each file within this directory acts as a separate plugin. They can be PHP files or folders containing PHP files, but they must not have the typical plugin header information at the top to avoid conflicts with the regular plugin directory.
History and Context
Must-Use Plugins were introduced in WordPress 1.2 as a means to provide site-wide functionality that could not be disabled by users, especially useful in a multisite environment:
- Originally, the concept was to provide plugins that were essential to the operation of the site or network.
- This functionality was enhanced in WordPress 3.0 with the introduction of Multisite capabilities, where MUs became even more relevant for network administrators.
Advantages
- Network-Wide Activation: Plugins in this directory automatically activate for all sites in a network.
- Performance: Since these plugins don't need to be checked for activation status, they can improve site performance slightly by reducing the number of checks WordPress performs.
- Security: They are less visible, which can help in hiding certain functionality from users or potential attackers.
- Control: Network administrators have full control over what is installed and active across all sites.
Disadvantages
- Lack of User Control: Users cannot deactivate these plugins, which can be a disadvantage in shared hosting environments where users expect more control.
- Maintenance: Updates to these plugins must be handled manually by the network administrator.
Usage
To use Must-Use Plugins:
- Create the
mu-plugins directory within wp-content/plugins/.
- Place PHP files or directories with PHP files inside this folder. Each file will be automatically loaded by WordPress.
- If you want to add plugin information, use the
register_activation_hook function to simulate a plugin header.
External Links
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