Files: wp-admin/includes/class-plugin-upgrader.php

Retrieve the path to the file that contains the plugin info.

Deactivates a plugin before it is upgraded.

Turns on maintenance mode before attempting to background update an active plugin.

Turns off maintenance mode after upgrading an active plugin.

Deletes the old plugin during an upgrade.

Initialize the upgrade strings.

Initialize the installation strings.

Install a plugin package.

Upgrade a plugin.

Bulk upgrade several plugins at once.

Check a source package to be sure it contains a plugin.

Check a source package to be sure it contains a plugin.

Retrieve the path to the file that contains the plugin info.

Deactivates a plugin before it is upgraded.

Turns on maintenance mode before attempting to background update an active plugin.