src\main.rs

use std::fs::File;
use std::io::{Read, Write};

use camino::Utf8Path;
use camino::Utf8PathBuf;
use walkdir::WalkDir;

fn main() -> std::io::Result<()> {
    let args: Vec<String> = std::env::args().collect();
    if args.len() != 3 {
        eprintln!("Usage: {} <input_directory> <output_file>", args[0]);
        std::process::exit(1);
    }

    let input_path = Utf8PathBuf::from(&args[1]);
    let output_path = Utf8PathBuf::from(&args[2]);
    let mut output_file = File::create(&output_path)?;

    for entry in WalkDir::new(&input_path) {
        let entry = entry?;
        let path = entry.path();
        if path.is_file() {
            writeln!(output_file, "{}\n", path.display())?;
            let mut file = File::open(path)?;
            let mut contents = String::new();
            file.read_to_string(&mut contents)?;
            write!(output_file, "{}", contents)?;
        }
    }

    Ok(())
}