wp_is_maintenance_mode(): bool

437function wp_is_maintenance_mode() {438	global $upgrading;439 440	if ( ! file_exists( ABSPATH . '.maintenance' ) || wp_installing() ) {441		return false;442	}443 444	require ABSPATH . '.maintenance';445 446	// If the $upgrading timestamp is older than 10 minutes, consider maintenance over.447	if ( ( time() - $upgrading ) >= 10 * MINUTE_IN_SECONDS ) {448		return false;449	}450 451	// Don't enable maintenance mode while scraping for fatal errors.452	if ( is_int( $upgrading ) && isset( $_REQUEST['wp_scrape_key'], $_REQUEST['wp_scrape_nonce'] ) ) {453		$key   = stripslashes( $_REQUEST['wp_scrape_key'] );454		$nonce = stripslashes( $_REQUEST['wp_scrape_nonce'] );455 456		if ( md5( $upgrading ) === $key && (int) $nonce === $upgrading ) {457			return false;458		}459	}460 461	/**462	 * Filters whether to enable maintenance mode.463	 *464	 * This filter runs before it can be used by plugins. It is designed for465	 * non-web runtimes. If this filter returns true, maintenance mode will be466	 * active and the request will end. If false, the request will be allowed to467	 * continue processing even if maintenance mode should be active.468	 *469	 * @since 4.6.0470	 *471	 * @param bool $enable_checks Whether to enable maintenance mode. Default true.472	 * @param int  $upgrading     The timestamp set in the .maintenance file.473	 */474	if ( ! apply_filters( 'enable_maintenance_mode', true, $upgrading ) ) {475		return false;476	}477 478	return true;479}