Show the OPcache hit rate

$status = opcache_get_status(false);
$stats  = $status['opcache_statistics'];

printf(
    "%.2f%% hits, %d of %d keys used, %.1f MB freen",
    $stats['opcache_hit_rate'],
    $stats['num_cached_keys'],
    $stats['max_cached_keys'],
    $status['memory_usage']['free_memory'] / 1048576
);