[WordPress] Redirect certain pages to 404

gistfile1.txt

/*
 * WP creates a lot of pages we don’t really need. First in the list of the unwanted is the attachment page.
 * Each image you upload gets its very own personal web page.
 * Also the archive by Author if you are a sole blogger is totally unneeded.
 * travel diaries maybe).
 */
function wpkTemplateRedirect ()
{
	global $wp_query, $post;

	if ( is_attachment() ) {
		$post_parent = $post->post_parent;

		if ( $post_parent ) {
			wp_redirect( get_permalink($post->post_parent), 301 );
			exit;
		}

		$wp_query->set_404();

		return;
	}

	if ( is_author() || is_date() ) {
		$wp_query->set_404();
	}
}
add_action( 'template_redirect', 'wpkTemplateRedirect' );