Hello world on the command line

Before we start building web applications using axum, first let’s go over step-by-step how you can start building an application.

In order to get started open a terminal window and type in the following:

cargo new hello-world

This will create a folder called hello-world with some basic files. Using the tree command available on Linux machines we can see the layout of the folder:

$ tree hello-world/
hello-world/
├── Cargo.toml
└── src
    └── main.rs

2 directories, 2 files

The Cargo.toml file contains the meta-data of the project sucha as the name of the crate thatwill be hello-world and the dependencies that we’ll add soon.

[package]
name = "hello-world"
version = "0.1.0"
edition = "2024"

[dependencies]

The main.rs file contains a very basic Rust application printing Hello, world! on the screen.

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

In addition a .gitignore file is also created

/target

and a git repository is set up for the project. So you’ll also find the .git folder.

Run the “application”

Let’s change into the directory of the project.

cd hello-world

and run the application:

cargo run

This will compile the application in the target/ folder (hence it was listed in the .gitignore file.), eventualy creating the target/debug/hello-world executable. This command will also run the executable printing Hello, world! to the screen.

It will also create a file called Cargo.lock that will hold the exact version of all the dependencies (both direct and indirect) of the project. For now it is mostly empty.

What’s next?

On the next pages we’ll see a number of examples. You can create a new crate for each example or your can simply replace the files in the current folder with the files of the example.