Effective C

I recently bought a book called Effective C: An introduction to Professional C Programming by Robert Seacord. I haven’t done any C programming in the last 15 years, so I thought it would be a good refresher. I want to find a hobby project that I could write in C (I’m still looking). I’ve mainly been writing C# professionally and I’ve written some Go on the side.

I enjoy programming languages that are simple enough to pick up quickly. I think C and Go are good examples of that. I’ve been wanting to learn a new systems programming language that doesn’t include a garbage collector, but Rust hasn’t felt appealing or simple enough for me to go out of my way to learn it. Zig and V feel interesting, but I know if either are mature enough. I’m also think Drew DeVault’s new language will be exciting to see when it lands.

Back to the book. I wanted to call out some of the things that were either new to me (since I last wrote C about 15 years ago) or things I never picked up on (in no particular order):

• _Alignof
• static_assert
• restrict keyword
• size_t (stddef.h)
• reserved names ending with _t
• integer conversions specifics
• integer promotions (and avoiding undefined behavior with an explicit cast: char c = '\xFF'; isdigit((unsigned char)c))
• _Atomic
• recommendation using f(void) rather than f() for functions without arguments
• enums
• bool (stdbool.h)
• flexible arrays (int data[] in a struct)
• variable length arrays (char msg[size] in a function block–alternative to alloca)
• struct field initialization point abc = { .x = 1, .y = 2};
• type generic macros (#define sin(X) _Generic((X), float: sinf, double: sin, long double: sinl)(X))

Overall, the book was nice, but short. At just over 200 pages, it’s an afternoon read. I was hoping it would go further than an “introduction” to professional C programming and spend more time discussing analysis tools to secure C programming. These days, it feels like you get chastised for choosing C for a new project due to security and safety. C still has a lot of foot guns, so it would have been nice to dive deeper than a few compile flags and a pointer to AddressSanitizer in the last couple of pages in the book.