Die with a maintenance message when conditions are met.

Checks for a file in the WordPress root directory named “.maintenance”. This file will contain the variable $upgrading, set to the time the file was created. If the file was created less than 10 minutes ago, WordPress enters maintenance mode and displays a message.

The default message can be replaced by using a drop-in (maintenance.php in the wp-content directory).

Signature

wp_maintenance()

Return

(void)

Source

function wp_maintenance() {
	if ( ! file_exists( ABSPATH . '.maintenance' ) || wp_installing() )
		return;

	global $upgrading;

	include( ABSPATH . '.maintenance' );
	// If the $upgrading timestamp is older than 10 minutes, don't die.
	if ( ( time() - $upgrading ) >= 600 )
		return;

	/**
	 * Filters whether to enable maintenance mode.
	 *
	 * This filter runs before it can be used by plugins. It is designed for
	 * non-web runtimes. If this filter returns true, maintenance mode will be
	 * active and the request will end. If false, the request will be allowed to
	 * continue processing even if maintenance mode should be active.
	 *
	 * @since 4.6.0
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