什么是makefile？或许很多Winodws的程序员都不知道这个东西，因为那些Windows的IDE都为你做了这个工作，但我觉得要作一个好的和professional的程序员，makefile还是要懂。-What is a makefile? Maybe a lot of Winodws programmers do not know this thing, because those are Windows-IDE for you to do this work, but I think that to make a good and professional programmers, makefile still have to understand.