public String exec(String command) {
    String line, output = "";
    try {
        ProcessBuilder builder = new ProcessBuilder(command.split(" "));
        Process process = builder.start();

        BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));

        while ((line = br.readLine()) != null) {
            System.out.println(line);
            output += line + "n";
        }
    } catch (IOException e) { e.printStackTrace(); }
    return output;
}