suppose I have a project named Proj, which include to folders, one is Proj1, another is Prjo2;
in Proj1, there are 3 cpp files : p1.cpp, p2.cpp, p3.cpp
in Proj2, there are another 2 files: p4.cpp, p5.cpp, p6.cpp

now I need write makefile to compile the Proj in linux environment. I think each folder there need a makefile, so total 3 makefiles are needed. How to write the makefiles to compile the project? Thanks!