I've been working as a Java programmer for several years and want to learn a second language for lower-level programming. My main goal is to explore and modify existing open-source operating systems, especially Linux or a BSD-based system, as a hobby rather than to build an operating system from scratch.
C appeals to me because its syntax and core concepts seem relatively simple, and it has been central to systems programming for decades. Rust is also interesting because it provides stronger memory-safety guarantees and is increasingly being used for system components, including parts of the Linux kernel and various core utilities.
Would learning Rust be more useful in the long term if it eventually becomes more common for operating-system development, or should I start with C?
3 Answers
For your specific goal, start with C. Most of the operating-system code you’ll be reading and modifying is still written in C, so learning it will make existing kernels, drivers, libraries, and tools much easier to understand. Working with pointers, memory management, data layout, and undefined behavior can be uncomfortable, but it teaches you what the machine is actually doing and why languages like Rust were designed the way they were.
C is still deeply established in operating systems and is unlikely to disappear anytime soon. Rust is valuable and its memory-safety guarantees are especially appealing for security-sensitive software, but its use in kernels and low-level infrastructure is still developing. A practical path would be to learn enough C to work comfortably with existing systems, then learn Rust afterward so you can compare its safety model and tooling with the problems C leaves to the programmer.
Don’t treat this as an either-or decision. The basic concepts of C can be learned fairly quickly by someone who already knows Java, and Rust can follow once you have some low-level experience. Try a small project in each language—such as a command-line utility, a memory allocator exercise, or a simple systems tool—and continue with whichever keeps you engaged. If you eventually want to write new, complex low-level software, Rust’s package management, tooling, and safety features may be a major advantage, while C remains the most useful language for understanding existing operating-system code.
That makes sense. I’m mainly interested in understanding and modifying existing systems, so being able to read the current codebase is probably more important than choosing the newer language first.