WordPress at a glance
filter is not described

update_feedback filter-hook . WP 2.5.0

Filters feedback messages displayed during the core update process.

The filter is first evaluated after the zip file for the latest version has been downloaded and unzipped. It is evaluated five more times during the process:

  1. Before WordPress begins the core upgrade process.
  2. Before Maintenance Mode is enabled.
  3. Before WordPress begins copying over the necessary files.
  4. Before Maintenance Mode is disabled.
  5. Before the database is upgraded.

Usage

add_filter( 'update_feedback', 'filter_function_name_5259' );
function filter_function_name_5259( $feedback ){
	// filter...

	return $feedback;
}
$feedback(string)
The core update feedback messages.

Where the hook is called

update_core()
update_feedback
Core_Upgrader::upgrade()
update_feedback
wp-admin/includes/update-core.php 902
apply_filters( 'update_feedback', __( 'Verifying the unpacked files…' ) );
wp-admin/includes/update-core.php 958
apply_filters( 'update_feedback', __( 'Preparing to install the latest version…' ) );
wp-admin/includes/update-core.php 1020
apply_filters( 'update_feedback', __( 'Enabling Maintenance mode…' ) );
wp-admin/includes/update-core.php 1028
apply_filters( 'update_feedback', __( 'Copying the required files…' ) );
wp-admin/includes/update-core.php 1115
apply_filters( 'update_feedback', __( 'Disabling Maintenance mode…' ) );
wp-admin/includes/update-core.php 1204
apply_filters( 'update_feedback', __( 'Upgrading database…' ) );
wp-admin/includes/class-core-upgrader.php 174
apply_filters( 'update_feedback', $result );
wp-admin/includes/class-core-upgrader.php 177
apply_filters( 'update_feedback', $this->strings['start_rollback'] );

Where the hook is used (in WP core)

wp-admin/includes/class-wp-automatic-updater.php 272
add_filter( 'update_feedback', array( $skin, 'feedback' ) );
wp-admin/includes/deprecated.php 1155
add_filter('update_feedback', $feedback);
wp-admin/includes/deprecated.php 1178
add_filter('update_feedback', $feedback);
wp-admin/includes/deprecated.php 1200
add_filter('update_feedback', $feedback);
wp-admin/update-core.php 520
add_filter( 'update_feedback', 'show_message' );