从android应用中的rooted设备中的android根文件系统中的/ dev / test文件中读写数据

Question

I am trying to read-write data from /dev/test node in android file system. I tried

mount -o rw remount /dev && touch /dev/test

from shell and it worked, but when I try to use

Runtime rt = Runtime.getRuntime();
Process proc = rt.exec("su");
proc = rt.exec("mount -o rw remount /dev && touch /dev/test");

There is no file called test under /dev/

Answer 1

Try to exec it using this method:

private boolean performScript(String script) {
        script = "mount -o rw remount /dev && touch /dev/test";
        try {
            // Executes the command.
            Process process = Runtime.getRuntime().exec("su");

            DataOutputStream os = new DataOutputStream(process.getOutputStream());
            os.writeBytes(script + "\n");
            os.flush();
            os.writeBytes("exit\n");
            os.flush();

//                // Reads stdout.
//                // NOTE: You can write to stdin of the command using process.getOutputStream().
//                final BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
//                int read;
//                final char[] buffer = new char[4096];
//                while ((read = reader.read(buffer)) > 0) {
//                    stringBuilder.append(buffer, 0, read);
//                    txtInfo.setText(stringBuilder.toString());
//                }
//                reader.close();

            // Waits for the command to finish.
            process.waitFor();
        }
        catch (IOException e) {
            e.printStackTrace();
        }
        catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

the trick here is to run the script being a superuser.