Wordpress - No more media attachment or author pages

functions.php

/**
 * Redirect away from attachment and author pages
 * Add this snippet to your functions or filters php files, as appropriate (if in doubt, the bottom of functions.php will do)
 * Feel free to message thisOlivier on github/stackOverflow if you get stuck
 * 
 */
add_action('template_redirect', function() {
    if (is_attachment() || is_author()) {
        global $post;
        if ($post && $post->post_parent) {
            wp_redirect(esc_url(get_permalink($post->post_parent)), 301);
            return;
        } else {
            wp_redirect(esc_url(home_url('/')), 301);
            return;
        }
    }
} );