Android :: Getting Result Of Executed Shell Command Fails / Hangs

I try to execute shell commands, this does work as it should. Even the result comes back (as is see on LogCat). The problem ist the last line of the result. Every time a readLine() on the last line occurs (which shouldn't occur, temp should be null), the app hangs forever and doesn't come back from the readLine call. Maybe you find the error. I tried readUTF and standart read(), all the same problem. And yes, the app got su-rights.

try {
Process process = Runtime.getRuntime().exec("su");
DataOutputStream os = new DataOutputStream(process.getOutputStream());
DataInputStream osRes = new DataInputStream(process.getInputStream());
for (String single : commands) { os.writeBytes(single + " ");
os.flush(); String temp = new String();
while( (temp = osRes.readLine()) != null) { Log.v("NITRO", temp);
result2 += temp + " ";
} } os.writeBytes("exit");
os.flush(); process.waitFor();
} catch (IOException e) { Toast.makeText(Main.this, "Error", Toast.LENGTH_LONG);
} catch (InterruptedException e){ Toast.makeText(Main.this, "Error", Toast.LENGTH_LONG);
}

That is the StackTrace where it hangs when I stop debugger when hanging:

OSFileSystem.readImpl(int, byte[], int, int) line: not available [native method]
OSFileSystem.read(int, byte[], int, int) line: 118
ProcessManager$ProcessInputStream(FileInputStream).read(byte[], int, int) line: 312
ProcessManager$ProcessInputStream(FileInputStream).read() line: 250
DataInputStream.readLine() line: 309
Main$2$1.run() line: 84
ViewRoot(Handler).handleCallback(Message) line: 587
ViewRoot(Handler).dispatchMessage(Message) line: 92
Looper.loop() line: 123
ActivityThread.main(String[]) line: 4627
Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]
Method.invoke(Object, Object...) line: 521
ZygoteInit$MethodAndArgsCaller.run() line: 868
ZygoteInit.main(String[]) line: 626
NativeStart.main(String[]) line: not available [native method]