public String exec(String cmd){
		InputStream in = null;
		String result = "";
		try{
			//if(this.login()){
				Session session = conn.openSession();
				session.startShell();
				session.getStdin().write(cmd.getBytes());
				session.getStdin().write("\n".getBytes());
				session.getStdin().flush();
				//session.execCommand(cmd);
				in = new StreamGobbler(session.getStdout());
				BufferedReader br = new BufferedReader(new InputStreamReader(in));
				String line = "";
				while((line=br.readLine())!=null){
					if(line.startsWith("Emit File size="))
						break;
				}
				result = line.split("=")[1];
				//br = new BufferedReader(new InputStreamReader(session.getStderr()));
				
				//System.out.println("stderr"+br.readLine());
				in.close();
			//}
		}catch(IOException e){
			
			e.printStackTrace();
		}
		return result;
	}