Comments are bit shit so I'll prolly give them a do-over at some point.
- https://man7.org/linux/man-pages/man2/signal.2.html
- https://man7.org/linux/man-pages/man7/signal.7.html
- http://www.cs.kent.edu/~ruttan/sysprog/lectures/signals.html
- https://linuxhint.com/signal_handlers_c_programming_language/
- https://www.geeksforgeeks.org/signals-c-language/
Used some stackexchange posts about bitshifting too, I'll try and find those and update when I do.