Rust for Beginners – Get Started with the Most Loved Programming Language

Rust has ranked as the most loved programming language on Stack Overflow‘s survey for 5 consecutive years now. This immense popularity stems from Rust solving long-standing problems in systems programming while also providing a modern and ergonomic developer experience.

In this comprehensive guide, we will understand what makes Rust uniquely suited for systems programming and why it promises to shape the future infrastructure powering our computing needs.

What is Systems Programming?

Before understanding Rust, we need to know what systems programming entails.

Systems programming refers to writing software that provides services to computer hardware and the operating system itself. This includes system utilities, compilers, drivers, kernels, embedded software on devices etc.

Systems code has some key requirements:

• Managing hardware resources efficiently – memory, CPU, storage etc.
• Executing operations very fast with low latency
• Communicating directly with the kernel and hardware
• Running reliably for long periods without crashing
• Ensuring safety and security against vulnerabilities

Typically systems code is written in low-level languages like C, C++ which give a lot of control but lack safety guarantees. Rust bridges this gap beautifully.

Rust‘s Core Features

Let‘s now understand features that make Rust so well-suited for systems programming:

Speed and Efficiency

Rust has minimal runtime and the compiler produces highly optimized native machine code rivaling C/C++ performance.

Features like zero-cost abstractions, move semantics, trait-based generics enable fast code that scales excellently.

The rich type system catches errors during compile time itself thereby eliminating overhead during runtime.

Memory Safety

Rust does not permit null or dangling pointers that lead to crashes in C/C++. The compiler ensures complete memory safety through Rust‘s ownership rules without the need for a garbage collector.

Values can be safely passed to functions or threads without worrying about invalid memory access. This enables writing low-level code fearlessly without introducing vulnerabilities.

Concurrency

Rust has first-class concurrency support through message passing and safe shared memory. The type system helps avoid race conditions at compile time itself.

Lightweight threads and actors make it easy to write asynchronous, parallel and scalable systems code.

Interoperability

Rust integrates well with other languages and has great interoperability with C code which is commonly used in operating systems and drivers.

Rust can reuse legacy C/C++ codebases via bindings exposing idiomatic Rust interfaces. This enables incrementally rewriting performance critical parts without needing to port everything.

Who Uses Rust and Why?

Many prominent companies are adopting Rust citing substantial improvements over existing systems code in C/C++/Go:

Microsoft

Microsoft is using Rust for various low level components across Azure, Windows, cloud services and more. They plan to rewrite several million lines of C/C++ code in Rust for better security, safety and ease of maintenance.

Amazon Web Services (AWS)

AWS Lambda is rewriting parts of their compute infrastructure managing containers and virtual machines in Rust for better performance.

Cloudflare

Cloudflare switched parts of their edge router from Go to Rust resulting in a 44% decrease in 95th percentile latency and 49% decrease in tail latency.

Some other companies using Rust in production – Dropbox, Coursera, Figma, Discord, Twitch etc.

Basic Rust Code Examples

Let‘s now look at some Rust code to get a feel for the language:

Here is a simple function printing "Hello World!":

fn main() {
  println!("Hello World!"); 
}

Declaring variables with explicit types:

let x: i32 = 5;
let float_num: f64 = 102.3;

Array with fixed size and type:

let nums: [i32; 5] = [1, 2, 3, 4, 5];
println!("Length {}", nums.len()); 

As we can see, Rust syntax is quite similar to other C-style languages but enhanced for safety through its rich type system around pointers, lifetimes, traits etc.

Now that we have seen a glimpse, let‘s go deeper into what really sets Rust apart.

Ownership and Borrowing

Rust‘s key innovation is introducing the concept of ownership combined with borrowing.

In Rust, every value has an owner responsible for cleanup once the value goes out of scope. When ownership of a value gets transferred, the previous reference gets invalidated avoiding dangling pointer issues.

Values can also be temporarily borrowed in a read-only or mutable way. The compiler tracks lifetimes of such borrows ensuring rules are not violated.

This ownership system enforced at compile time itself eliminates entire classes of memory safety issues. Code executed remains within safe boundaries without runtime overhead.

Let‘s see this with some examples:

// x gets created and its ownership moves to f1 
fn f1(x: i32) {
   println!("{}", x); // x gets destroyed here automatically  
}

fn main() {
   let x = 10; // x gets created and bound to 10
   f1(x); // Ownership moves to f1 
   println!("{}", x); // Error since x is now invalid
}

Now let‘s borrow values instead of transferring ownership:

fn borrow_i32(x: &i32) { // Borrow x read-only
   println!("From borrow={}", x); // Can access x 
}

fn main() {
   let x = 10; 
   borrow_i32(&x); // Borrow a reference to x
   println!("{}", x); // We still own x here  
}

These safety guarantees enable Rust to match C/C++ performance without worrying about crashes or security exploits.

Cargo – Rust‘s Build System and Package Manager

Cargo is Rust‘s official package manager and build system. It can be used to:

• Initialize new Rust projects
• Manage dependencies
• Build Rust code (no need for makefiles)
• Run tests
• Generate documentation
• Publish libraries to crates.io

For example, creating a new Rust binary project with Cargo:

cargo new myprogram
cd myprogram
cargo build
cargo run

This automatically scaffolds a simple Rust project allowing us to build and run it.

Cargo fetches external crates (Rust‘s version of libraries/packages) from crates.io – the official Rust package registry containing thousands of useful Rust modules.

For example, adding the popular regex crate:

[dependencies] 
regex = "1"

Cargo seamlessly fetches and builds regex enabling us to use it in our code. This makes dependency management and code distribution very smooth.

Rust Learning Resources

I hope this post has provided a good high-level overview of why Rust is revolutionizing systems programming. Here are some great resources to level up your Rust skills:

Books:

• The Rust Programming Language – Rust‘s official book (must read)
• Rust in Action – Practical projects demonstrating Rust concepts

References:

• The Rust Reference – Detailed technical reference for language concepts
• Rust By Example – Hands-on examples explaining features

Channels:

• This Week in Rust – Latest updates from the Rust ecosystem
• RustFest – Conference talks on Rust use cases

Start tinkering with Rust using the Rust Playground website to practice the language constructs without needing any setup locally.

Additionally, the welcoming Rust online community and documentation available make it easy for programmers from any background to successfully pick up Rust.

Conclusion

Rust truly brings together the raw power of low level languages with modern safety guarantees through innovations like the borrow checker. The learning curve pays rich dividends enabling writing systems software that runs blazingly fast yet securely. Rust is undoubtedly revolutionizing the systems programming landscape – rightly poised to become the language of choice for software that runs the world!