实现如何在cocoa中运行shell指令。并获取shell的返回信息。最终显示在NStextView中-a Sample code about how to running shell command in cocoa, and get info from the shell return value. finally show them in a NSTextView.

自定义combobox，很简单的一段代码，希望能帮助别人-a combobox，I hope it can help anyone who need this。