Question

I need to get the Integer input from the user ( from the EditText numerical ) to make it to a command line, But I don’t seem to get it working, if I change the cmd line to ( “echo 255 > … “) it works, but if I try to place the user input instead of the 255 it doesn’t.

Here is the code.

public class main extends Activity  {

EditText value;
int uin;



/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);


    value = (EditText) findViewById(R.id.editText2);

    try {
        Process process = Runtime.getRuntime().exec("su");
    DataOutputStream os = new  DataOutputStream(process.getOutputStream());
     {
       os.writeBytes("mount -o rw,remount -t yaffs2  /dev/block/mtdblock03 /system\n" +
               "exit \n");
       os.flush();
    process.waitFor();
    }

    } catch (IOException e) {
        e.printStackTrace();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }

    //Button OK

    Button bOK = (Button) findViewById(R.id.bOK);
    bOK.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            // TODO Auto-generated method stub

            uin = Integer.parseInt(value.getText().toString());

            Process process = null;
            try {
                process = Runtime.getRuntime().exec("su");
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            DataOutputStream os = new 

      DataOutputStream(process.getOutputStream());
            try {
                os.writeBytes("chmod 644 sys/class/leds/button-backlight/brightness\n");
                os.writeBytes("echo" +uin+ "> sys/class/leds/button-backlight/brightness\n");
                os.writeBytes("chmod 444 sys/class/leds/button-backlight/brightness\n");
                os.writeBytes("exit\n");
                os.flush();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

Answer 1

My first guess would be your lack of spaces.

If echo 255 > ... works, that’s great, but using the + to concatenate a string together doesn’t add implied spaces, so your code will currently produce echo255> sys/class... if uin = 255. In other words, try:

os.writeBytes("echo " +uin+ " > sys/class/leds/button-backlight/brightness\n");

HTH