public void runShell() {
		exitShell = false;
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		try {
			while (!exitShell) {
				System.out.print(">> ");
				String line = br.readLine();
				String args[] = line.split(" ");
				if (args.length < 1) {
					showShellHelp();
				} else {
					CmdHandler handler = cmdTable.get(args[0]);
					if (handler == null) {
						showShellHelp();
					} else {
						// run command
						try {
							handler.handleCmd(args);
						} catch (IOException ex) {
							ex.printStackTrace();
						}
					}
				}
			}
		} catch (Exception ex) {
			exitShell = true;
			ex.printStackTrace();
		}
	}