How to List SD Card directory content Arduino Platform

list_sdcard.ino

Serial.println("List dir");
File root = SD.open("/");
File file = root.openNextFile();
while (file) {
	Serial.print("FILE: ");
	Serial.println(file.name());
	file = root.openNextFile();
}

Serial.println("opening...");
File f = SD.open("/test.wav", "r");
if (!f) {
	Serial.println("file open failed!");
}
else {
	Serial.println("file open OK!");
	f.close();
}