Cargo exercises - rust-course

50.1.1First project¶

50.1.1.1New project¶

We first initialize a new project with the init sub-command. It will create the folder, a Rust code file with a main function inside and a Cargo.toml file:

cargo init hello

    Creating binary (application) package

note: see more `Cargo.toml` keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

We enter the hello folder and build the project:

cd hello
cargo build

   Compiling hello v0.1.0 (/tmp/tmp.iGVibFZrsl/hello)

    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.19s

We run the project, a Hello, world! is printed:

cargo run

    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s

     Running `target/debug/hello`

Hello, world!

50.1.1.2Using a crate dependency¶

We add the text2art crate as a dependency:

cargo add text2art

    Updating crates.io index

warning: failed to write cache, path: /usr/local/cargo/registry/index/index.crates.io-1949cf8c6b5b557f/.cache/te/xt/text2art, error: Permission denied (os error 13)

      Adding text2art v1.0.2 to dependencies

    Updating crates.io index

warning: failed to write cache, path: /usr/local/cargo/registry/index/index.crates.io-1949cf8c6b5b557f/.cache/te/xt/text2art, error: Permission denied (os error 13)

     Locking 7 packages to latest Rust 1.95.0 compatible versions

      Adding aho-corasick v1.1.5

      Adding memchr v2.8.3

      Adding regex v1.10.6 (available: v1.13.1)

      Adding regex-automata v0.4.18

      Adding regex-syntax v0.8.11

      Adding text2art v1.0.2

      Adding unicode-segmentation v1.10.1 (available: v1.13.3)

See the added lines for the dependency into the project file:

bat Cargo.toml

[package]

name = "hello"

version = "0.1.0"

edition = "2024"

[dependencies]

text2art = "1.0.2"

We write now the new code into the src/main.rs file:

cat >src/main.rs <<EOF
use text2art::BasicFonts;
use text2art::Font;
use text2art::Printer;

fn main() {
  let font = Font::from_basic(BasicFonts::Big).unwrap();
  let prntr = Printer::with_font(font);
  prntr.print_to_stdio("Hello, world!").ok();
}
EOF

bat src/main.rs

use text2art::BasicFonts;

use text2art::Font;

use text2art::Printer;

fn main() {

  let font = Font::from_basic(BasicFonts::Big).unwrap();

  let prntr = Printer::with_font(font);

  prntr.print_to_stdio("Hello, world!").ok();

We rebuild the application:

cargo build

    Updating crates.io index

warning: failed to write cache, path: /usr/local/cargo/registry/index/index.crates.io-1949cf8c6b5b557f/.cache/te/xt/text2art, error: Permission denied (os error 13)

 Downloading crates ...

  Downloaded text2art v1.0.2

error: failed to open `/usr/local/cargo/registry/cache/index.crates.io-1949cf8c6b5b557f/text2art-1.0.2.crate`

Caused by:

  Permission denied (os error 13)

Fetching long content....

And run it to print the same message in ASCII Art:

cargo run

50.1 Cargo exercises

50.1.1First project¶

50.1.1.1New project¶

50.1.1.2Using a crate dependency¶