Не могу выйти из цикла while

public class Main
{
public static void main(String[] args) throws IOException
{

Process p = Runtime.getRuntime().exec("bash");
DataInputStream dis = new 
DataInputStream(p.getInputStream());
DataOutputStream dos = new 
DataOutputStream(p.getOutputStream());
//BufferedInputStream bis = new 
BufferedInputStream(p.getInputStream());

InputStream is = p.getInputStream();

dos.writeBytes("ps\n");
dos.flush();

int n;
while((n=is.read())!=-1){
System.out.print((char)n);
}
System.out.println("END");


}
}