fileSize method
Implementation
Future<String> fileSize({int decimal = 1}) async {
int bytes = await length();
if (bytes <= 0) {
return "0 B";
}
const suffixes = ["B", "KB", "MB", "TB", "PB", "EB", "ZB", "YB"];
final index = (log(bytes) / log(1024)).floor();
return "${(bytes / pow(1024, index)).toStringAsFixed(decimal)} ' ' ${suffixes[index]}";
}