Android 使用su命令读取设备中隐藏的文件和文件内容

/**
     * 执行 dos 命令
     * @param cmd
     * @return
     */
    public static String execRootCmd(String cmd) { //cmd=cat proc/cmdline `
        String result = "";
        DataOutputStream dos = null;
        DataInputStream dis = null;
        try {
            Process p = Runtime.getRuntime().exec("su");// 经过Root处理的android系统即有su命令
            dos = new DataOutputStream(p.getOutputStream());
            dis = new DataInputStream(p.getInputStream());

            dos.writeBytes(cmd + "\n");
            dos.flush();
            dos.writeBytes("exit\n");
            dos.flush();
            String line = null;
            while ((line = dis.readLine()) != null) {
                result += line;
            }
            p.waitFor();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (dos != null) {
                try {
                    dos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (dis != null) {
                try {
                    dis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return result;
    }