title: Can not replace file in /system/fonts folder in Android rooted device
body: <p>I try to replace <strong>DroidSansFallback.ttf</strong>  by  <strong>myfont.ttf</strong> in /sdcard like this</p>
  
  <pre><code>    try {
          Process p = Runtime.getRuntime().exec("su");
          DataOutputStream outs=new DataOutputStream(p.getOutputStream());
          outs.writeBytes("mount -o rw,remount /system"+"\n");
          outs.writeBytes("cat /sdcard/myfont.ttf &gt;&gt; /system/fonts/DroidSansFallback.ttf"+"\n");
          outs.writeBytes("mount -o rw,remount /system"+"\n");
          outs.flush();
      } catch (IOException e) {
          e.printStackTrace();
      }
  </code></pre>
  
  <p>I can copy DroidSansFallback out to /sdcard by this way but can NOT copy back.
  Please help if you know the correct way to replace DroidSansFallback font in rooted device.</p>