There does not seem to be a good way on Linux to get the free disk space of your / partition with a C function. This is very annoying. I tried to update my system information program with a simple function that shows free disk space with C and I could not get the statfs64() function to work properly. I guess there is another function that is available that I need to find. Unless I use boost, that offers a function that I could use. Anyway, this is only a minor setback, I will get this working very soon. I guess I could use execl() and a proper Linux command within that to get the same information. That would work very well. But programming on Linux really is very good. I worked out how to add a remote github repository to my local machine so I can push changes up to the repo with the command line. That is the way to do it properly. That is why the Linux command line is so useful. I am sure this would work with the Windows 10 bash shell as well. Then I could do programming on Windows 10 and push the changes to a repository.
I have not used Windows 10 for quite a while, but I am sure it has undergone quite a few changes since I last used it. Using the Linux command line on an actual Linux system is the way to go, this gives good access to many manual pages and a fast responsive Fedora 25 system. That is the advantage it has over a Windows system.