Rust Programming Language: Basic Project Workflow with Cargo

Rust is a systems programming language focused on safety, performance, and concurrency. It achieves memory safety without using a garbage collector, and its powerful type system and ownership model guarantee memory safety and thread safety.

Cargo is Rust’s build system and package manager. It handles tasks like:

• Creating new Rust projects.
• Building your code.
• Downloading and compiling your code’s dependencies.
• Running tests.
• Generating documentation.

1. Creating a New Rust Project (cargo new)

The cargo new command is used to create a new Rust project (either an executable application or a library) with a standardized directory structure.

cargo new <project-name>
# Example:
cargo new my-rust-app

• <project-name>: The name of your new project. Cargo will create a directory with this name.

By default, cargo new creates a binary project (an executable application).

• To create a binary project: cargo new <project-name> (default) or cargo new <project-name> --bin.
• To create a library project: cargo new <project-name> --lib.

2. Basic Cargo Commands

Once you’ve created a project, navigate into its directory (cd my-rust-app).

Build the Project (cargo build)

This command compiles your project’s source code and its dependencies into an executable binary (for binary projects) or a library (for library projects). The compiled output is placed in the target/debug/ directory.

cargo build

Run the Project (cargo run)

This command compiles your project (if necessary) and then runs the resulting executable. It’s a convenient way to execute your application during development.

cargo run

Check the Project (cargo check)

cargo check performs a fast compilation check without actually producing an executable. It’s useful for quickly catching errors as you code, without waiting for a full build.

cargo check

Run Tests (cargo test)

This command compiles and runs all tests defined in your project.

cargo test

3. Automatic Re-execution on File Changes (cargo watch)

cargo watch is a third-party utility that automatically re-executes specified Cargo commands whenever your source code files change. This is incredibly useful for rapid development feedback.

Installation

cargo install cargo-watch

Usage: Automatically Rerun Tests

cargo watch -x test

• -x test: Executes cargo test whenever a relevant file changes. You can replace test with any other Cargo subcommand (e.g., run, build, check).

Usage: Automatically Rerun the Application

cargo watch -x run

This command is perfect for web development or services that need to restart upon code changes.