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.

实现了在cocoa中的shell运行。示例中使用的就是shell命令中的ping指令，最终将其显示在textView中-Achieved in the cocoa in the shell to run. Sample is used in shell command ping and eventually be displayed in the textView