listdir.rs

use std::io;
use std::env;
use std::fs::{self, DirEntry};
use std::path::Path;

fn visit_dirs(dir: &Path, cb: &Fn(&DirEntry)) -> io::Result<()> {
    if dir.is_dir() {
        for entry in fs::read_dir(dir)? {
            let entry = entry?;
            let path = entry.path();
            
            if let Some(filename) = path.file_name().and_then(|s| s.to_str()) {
                if filename.starts_with(".") {
                    continue;
                }
            } 
            if path.is_dir() {
                visit_dirs(&path, cb)?;
            } else {
                cb(&entry);
            }
        }
    }
    Ok(())
}

fn main() {
    let args : Vec<String> = env::args().collect();
    if args.len() < 2 {
        println!("Usage: {} <dirname>", args[0]);
        return
    }
    visit_dirs(Path::new(&args[1]), &|entry : &DirEntry| {
        println!("{}", entry.path().to_str().expect("Path should be a valid string"));
    }).expect("Current dir not found");
}