Rust - Getting Started

Note

The following is my notes taken while reading The Rust Programming Language by Steve Klabnik and Carol Nichols, which was recommended to me by the awesome Rust community. I preferred to go over a book and not the online one, because once it’s on my desk and I don’t open it, I feel ashamed and have to open it 🥲 I call it self-shaming manipulation to do the damn work

Let’s create the famous (or infamous, depends on who you are) Hello, World program:

fn main() {
    println!("Hello, world!");
}

The main function is always the first code that runs in every executable Rust program.

rustc main.rs

The line above calls the rust compiler to compile the main.rs file.

Hello, Cargo

Cargo is Rust’s build system and package manager.

Creating a project with cargo:

cargo new hello_cargo
cd hello_cargo

This should generate a project with several files: Cargo.toml:

[package] # the following statements are configuring a package
name = "hello_cargo" # name of the packagae
version = "0.1.0" # version
edition = "2021" # the edition of rust

[dependencies] # section of deps

In Rust, packages of code are referred to as crates

src/main.rs:

fn main() {
    println!("Hello, world!");
}

Cargo expects your source files to live inside the src directory, the top level directory is just for README files, license information, configuration files, and anything else not related to your code.

Building and Running a Cargo project:

cargo build
./target/debug/hello_cargo -> Hello, world!

cargo build also creates a new file at the top level: Cargo.lock:

# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
version = 3

[[package]]
name = "hello_cargo"
version = "0.1.0"

This file keeps track of the exact versions of dependencies in your project.

• We can compile and run the resultant executable with just one command: cargo run
• We can use cargo check to quickly check that your code is compiling, which is often much faster than cargo build because it is not producing an executable.

Summary of cargo commands:

• cargo new - generates a new project. s- cargo build - builds the current project.
• cargo check - builds the project without producing binary
• cargo run - build and run in one command

Building for Release

When your project is ready to be released, you should use the cargo build --release to compile it with optimizations, this command will create an executable inside target/release folder.