C Pro

This is a solid baseline for writing C code that doesn't leak memory or crash on you. It pushes proper malloc/free discipline, return value checking, and demands valgrind-clean output, which is exactly the kind of rigor that separates hobby C from production C. The focus on POSIX compliance, pthreads, and embedded constraints makes it useful for systems work, not just toy programs. It won't teach you C from scratch, but if you already know the language and want guardrails around memory management and debugging workflow, it's a practical starting point. The insistence on Makefiles with proper warnings and unit tests is a nice touch that encourages sustainable code rather than quick hacks.