WordPress: Disable WP updates and plugin updates

disable-wp-and-plugins-updates.php

<?php
// Disable WordPress updates and plugins updates
// @file functions.php

// disable updates
add_filter( 'pre_site_transient_update_plugins', create_function( '$a', "return null;" ) );
remove_action( 'load-update-core.php', 'wp_update_plugins' );
// or: Remove WordPress Update Notification
add_action( 'init', create_function( '$a', "remove_action( 'init', 'wp_version_check' );" ), 2 );
add_filter( 'pre_option_update_core', create_function( '$a', "return null;" ) );
?>