说明：  要作一个好的和professional 的程序员， makefile还是要懂。特别在Unix下的软件编译，你就不能不自己写makefile了，会不会写makefile，从一个侧面说明了一个人是否具备完成大型工程的能力。
(To make a good and professional programmers, makefile still have to understand. Especially in the software compiled under Unix, you can not write your own makefile, and will not write makefile, from one side shows whether a person has the ability to complete major projects.)