Laravel 5 如何读取config/filesystems.php的值

如何在laravel 5.8中使用默认值读取config/filesystems.php的值：

return [

    'default' => env('FILESYSTEM_DRIVER', 'local'),


    'cloud' => env('FILESYSTEM_CLOUD', 's3'),


    'disks' => [

        'local' => [
            'driver' => 'local',
            'root' => storage_path('app'),
        ],

        'public' => [
            'driver' => 'local',
            'root' => storage_path('app/public'),
            'url' => env('APP_URL').'/storage',
            'visibility' => 'public',
        ],

我期望：

$filesystem_pablic_path  = config('filesystem.disks.public');

但返回空值…

请尝试复数形式$filesystem_pablic_path=config'filesystems.disks.public'