Android : Is this below code is correct for saving logcat details to a file in eclipse?

public static void saveLogcatToFile(Context context) {

String fileName = "logcat_"+System.currentTimeMillis()+".txt";

File outputFile = new File(context.getExternalCacheDir(),fileName);

@SuppressWarnings("unused")

Process process = Runtime.getRuntime().exec("logcat -f "+outputFile.getAbsolutePath());  }

Please check the above code and help me to save the logcat details to file (permanently), it should append after everytime debugging in eclpise.