[Jetpack] Check of Tonesque's file is readable https://cloudup.com/cKET0dvWlaX

plugin.php

<?php
/*
 * Plugin Name: Check Jetpack's Tonesque
 * Plugin URI: http://wordpress.org/extend/plugins/jetpack/
 * Description: Check if the Tonesque file is readable
 * Author: Jeremy Herve
 * Version: 1.0
 * Author URI: http://jeremyherve.com
 * License: GPL2+
 */
function jeherve_check_tonesque_readable() {
    $tonesque = plugin_dir_path( __FILE__ ) . '../jetpack/_inc/lib/tonesque.php';
    if ( is_readable( $tonesque ) ) {
        echo 'The file is readable';
    } else {
        echo 'The file is not readable';
    }
}
add_action( 'wp_footer', 'jeherve_check_tonesque_readable' );