public static String runExternalCommand(String cmd) {
        String output = "";
        String errMsg = "";

        try {
            Process command = Runtime.getRuntime().exec(cmd);

            BufferedReader in = new BufferedReader(new InputStreamReader(
                    command.getInputStream()));
            String line = "";
            while ((line = in.readLine()) != null) {
                output += line + "\n";
            }
            in.close();

            BufferedReader br = new BufferedReader(new InputStreamReader(
                    command.getErrorStream()));

            while ((line = br.readLine()) != null) {

                errMsg += line + "\n";

            }
            br.close();

        } catch (Exception e) {
            Log.v("AppImp",
                    "Exception when trying to execute external command "
                            + e.getMessage());
        }
        Log.v("AppImp", output);
        Log.v("AppImp", errMsg);
        return output;
    }