strace is a tool that inspect what an application is doing. You can strace application on launch or attach a running one to strace using its PID. It will show you all files and system call calls the process is using and calling.
This is a nice introduction on strace with examples.
I took the Linux Kernel fundamentals course on Linkedin Learning during the Week of Learning. I went through the first three lessons. The last two deals with compiling the kernel. I skipped them as I had done some kernel compiling years ago and I won’t be doing them anytime soon.
These are my notes from the lessons:
I have always thought Virtual Filesystems like /proc and /sys are stored in memory, they are not. They are generated when asked for it. Each file and directory has associated function in the kernel that generates the content when you ask.