java - android在/dev中写入文件

Question

我正在尝试将文件写入/ dev，代码如下我在日志中收到错误。我做错了什么..我正在使用模拟器来测试这个..这应该在实际设备上完成吗？

  try {
        process = Runtime.getRuntime().exec("su");
        OutputStream os = process.getOutputStream();
        DataOutputStream dos = new DataOutputStream(os);
        String cmd = "echo 'hello world'> /dev/pttycmd1";
        String  cmd1 = "echo 'hello world2'> /dev/pttycmd2";
        dos.writeBytes(cmd);
        dos.writeBytes(cmd1);
        dos.flush();
        File f = new File("/dev/pttycmd1");
        if(f.exists())
        { 
             /* do something */ 
            Log.d("success", "File exists");
        }
        else
        {
            Log.d("error", "File does not exists");
              //file.mkdirs();
              //And your other stuffs goes here
        }
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

Answer 1

/dev普通用户不可写。可能谁root也写不出来/dev