', esc_url( get_bloginfo( 'pingback_url' ) ) ); } } add_action( 'wp_head', 'newsbook_pingback_header' ); /** * Sets the post excerpt length to 40 words. * * @param mixed $length Excerpt length. * @return number */ function newsbook_excerpt_length( $length ) { return 25; } add_filter( 'excerpt_length', 'newsbook_excerpt_length' );