Learning C, No AI: Input/Output, typedef, pointers II (Beej's Guide)

Learning C programming from scratch with no AI coding. Working through Beej's Guide to C: chapter 9 Input/Output. Previous stream - "Learning C: Beej's Guide #8 Structs...":    • Learning C: Beej's Guide #8 - Structs, Str...   Playlist - "Learn C, no ai coding":    • Learn C, no ai coding   Chapters: 00:00 recap of Input/Output 04:00 writing output to a file 08:18 Binary file Input/Output 13:50 Binary read 23:33 typedef: Making new types 28:10 typedef in practice 36:10 Pointers II Arithmetic 39:20 add/subtracting to pointers 45:00 writing own strlen() 52:52 Array Pointer equivalence Why? Data Engineer for 4+ years, but a beginner to systems programming & also been inspired by others on YouTube to get involved by learning a low level language and looking at stuff like memory and all the fun bits… I do have some experience with the likes of Python, C# from playing around with unity, SQL etc. but nothing to the same depth as what I'm trying to learn in c.