The Cargo Book

To start a new project with Cargo, use cargo new:

$ cargo new hello_world --bin

We’re passing --bin because we’re making a binary program: if we were making a library, we’d pass --lib.

Let’s check out what Cargo has generated for us:

$ cd hello_world
$ tree .
.
├── Cargo.toml
└── src
    └── main.rs

1 directory, 2 files

This is all we need to get started. First, let’s check out Cargo.toml:

[package]
name = "hello_world"
version = "0.1.0"
authors = ["Your Name <you@example.com>"]

This is called a manifest, and it contains all of the metadata that Cargo needs to compile your project.

Here’s what’s in src/main.rs:

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

Cargo generated a “hello world” for us. Let’s compile it:

$ cargo build
   Compiling hello_world v0.1.0 (file:///path/to/project/hello_world)

And then run it:

$ ./target/debug/hello_world
Hello, world!

We can also use cargo run to compile and then run it, all in one step:

$ cargo run
     Fresh hello_world v0.1.0 (file:///path/to/project/hello_world)
   Running `target/hello_world`
Hello, world!

For more details on using Cargo, check out the Cargo Guide