How does CMake work? What does it do exactly?

CMake files are used to generate make files which automate the compilation and building process by running the suitable compilers and linkers.

Why do we need it ?

A reliable software depends on other libraries and software as well, so there was a need for another “software” or “tool” that organize and order the compilation, linking and building process.

Can we work without it ?

Yes, If the project is simple and small, we can use a simple text file written with a simple text editor like notepad, and pass it to a simple compilation and building commands within a terminal to get our target, an exe file or a library.

I am not familiar with it ! Why ?

Because you used to use the IDE “Integrated Development Environments” like visual studio and QT which in most of cases makes all the tasks instead of you, it offers you a text editor , an autocomplete feature, a compiler, a linker a debugger, etc.. and that is why it is “Integrated” development Environment

How do we write such file ?

Not all of your source codes are intended to be an executable, some will be a dynamic library, another could be a static and so on. You tell this file where is your header and source files, and which file will be an exe and which will be a library “if needed” and which external libraries you will link to your exe “target”

Finally you pass this file to the CMake program/command which in turn generates a make file. The make file is then passed to the make command/software to make your targets ready :)

Good Luck :)