This code snippet disables all feed types in WordPress (RSS, Atom, RDF) and displays a custom message directing users to the homepage. Ideal for sites that do not want to offer feed capabilities.

disable-wordpress-rss-feeds.php

function wpb_disable_feed() {
    wp_die( __('No feed available, please visit our <a href="' . 
    get_bloginfo('url') . '">homepage</a>!') );
}

add_action('do_feed', 'wpb_disable_feed', 1);
add_action('do_feed_rdf', 'wpb_disable_feed', 1);
add_action('do_feed_rss', 'wpb_disable_feed', 1);
add_action('do_feed_rss2', 'wpb_disable_feed', 1);
add_action('do_feed_atom', 'wpb_disable_feed', 1);
add_action('do_feed_rss2_comments', 'wpb_disable_feed', 1);
add_action('do_feed_atom_comments', 'wpb_disable_feed', 1);