.RS

Introduction

A .rs file holds source code in Rust, a compiled systems programming language. The Rust compiler, rustc, usually run through the Cargo build tool, turns a crate (a tree of .rs files) into a program or library.

A crate’s root file is normally src/main.rs for a program or src/lib.rs for a library, with a Cargo.toml file in the folder above that names the crate and its dependencies.

Structure

A Rust source file is plain text and must be UTF-8. It holds items: functions, structs, enums, traits, impl blocks and modules. A line such as mod parser; tells the compiler to read the module from parser.rs or parser/mod.rs next to the current file, so the files of a crate form a tree that starts at its root file. Comments starting /// and //! are documentation, which the rustdoc tool turns into web pages.

use std::env;

/// Prints a greeting for each name given on the command line.
fn main() {
    for name in env::args().skip(1) {
        println!("Hello, {name}");
    }
}

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