First Steps with Cargo

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

1. $ cargo new hello_world

Cargo defaults to —bin to make a binary program. To make a library, we'dpass —lib.

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

1. $ cd hello_world
2. $ tree .
3. .
4. ├── Cargo.toml
5. └── src
6. └── main.rs

8. 1 directory, 2 files

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

1. [package]
2. name = "hello_world"
3. version = "0.1.0"
4. authors = ["Your Name <you@example.com>"]
5. edition = "2018"

7. [dependencies]

This is called a manifest, and it contains all of the metadata that Cargoneeds to compile your package.

Here’s what’s in src/main.rs:

1. ```
   fn main() {
   ```
2. ```
       println!("Hello, world!");
   ```
3. ```
   }
   ```

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

1. $ cargo build
2. Compiling hello_world v0.1.0 (file:///path/to/package/hello_world)

And then run it:

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

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

1. $ cargo run
2. Fresh hello_world v0.1.0 (file:///path/to/package/hello_world)
3. Running `target/hello_world`
4. Hello, world!

Going further

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