I've been working as a Java programmer for several years and want to learn a second language for lower-level systems work as a hobby. My main interest is exploring and modifying existing open-source operating systems, such as Linux or a BSD variant, rather than building an operating system from scratch.
C appeals to me because it is relatively small, straightforward, and 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 utilities and some operating-system components.
For this goal, should I start with C because most existing kernel code is written in it, or learn Rust because it may become more important for operating-system development in the future?
5 Answers
Rust is a worthwhile choice if you prefer stronger compiler checks and safer memory handling. It prevents many classes of bugs that are common in C, and its tooling and abstractions can make larger projects more manageable. However, Rust’s growing use doesn’t make it the universal standard, so I’d choose it based on the specific component you want to study.
Learn C first, then add Rust. C gives you a foundation in pointers, memory management, data layout, compilation, and system calls. Once those concepts are familiar, Rust’s ownership and borrowing rules will be easier to understand, and you can use Rust where its safety guarantees are especially valuable.
There isn’t one language that will remain the most useful forever. C is essential for understanding much of today’s operating-system code, while Rust offers a different and increasingly important approach to systems programming. Since this is a hobby, start with whichever motivates you, then learn the other when a project gives you a reason to use it.
Start with C. Linux and the BSDs contain a huge amount of C, so learning it will make the codebase, APIs, memory model, and low-level behavior much easier to understand. C is small enough that you can get through the fundamentals quickly, and it exposes details that higher-level languages often hide.
That makes sense. I’m mainly interested in being able to read and modify existing systems code, so familiarity with the dominant language seems useful.
The language itself matters less than building something substantial. Try writing a small shell, memory allocator, toy filesystem, or other compact systems project in C. That will teach you more about operating-system concepts than debating which language might dominate years from now.
Rust adoption is growing, but that doesn’t mean C will disappear from Linux or BSD anytime soon. Knowing both lets you work with existing code while also exploring newer components.