Regenerate post slugs

<?php
require 'wp-load.php';

echo "Regenerating post slugs...<br />\n";
$posts = $wpdb->get_results( "SELECT ID, post_title, post_name FROM {$wpdb->posts} WHERE post_status = 'publish'" );
foreach ( (array) $posts as $post ) {
    $post_name = sanitize_title( $post->post_title );
    if ( $post_name !== $post->post_name ) {
        add_post_meta( $post->ID, '_wp_old_slug', $post->post_name );
        $wpdb->update( $wpdb->posts, array( 'post_name' => $post_name ), array( 'ID' => $post->ID ) );
    }
}

echo 'All done!';
?>