How to Use Derive-Based Argument Parsing with clap

Use the #[derive(Parser)] attribute on a struct to automatically generate command-line argument parsing logic for clap.

use clap::Parser;

#[derive(Parser, Debug)]
#[command(name = "minigrep")]
struct Config {
    #[arg(short, long)]
    query: String,

    #[arg(short, long)]
    file_path: String,
}

fn main() {
    let config = Config::parse();
    println!("Searching for {} in {}", config.query, config.file_path);
}

This replaces manual env::args() parsing and Config::build() methods with a single Config::parse() call.

Derive-based parsing lets you define your command-line arguments as a simple data structure, and clap automatically handles the rest. Instead of writing code to manually read and validate input, the compiler generates the logic for you based on your struct fields. It's like filling out a form where the system automatically checks if you filled in the required boxes before submitting.