[code] small improvements suggested by Grok 3

- differentiate between "not a directory" and a real error while reading the path
- don't clone the PathBuf, instead use Arc

src/main.rs

@@ -2,11 +2,12 @@ use std::{
     net::{IpAddr, SocketAddr},
     num::NonZeroUsize,
     path::PathBuf,
+    sync::Arc,
     thread::available_parallelism,
 };
 
 use actix_web::{App, HttpServer};
-use clap::{crate_name, crate_version, Parser};
+use clap::{Parser, crate_name, crate_version};
 
 #[derive(Parser, Debug)]
 #[clap(name = crate_name!(), version = crate_version!())]
@@ -25,11 +26,11 @@ struct Args {
 }
 
 fn parse_valid_dir(dir: &str) -> Result<PathBuf, String> {
-    let path = std::path::Path::new(dir);
+    let path = PathBuf::from(dir);
-    if path.is_dir() {
+    match std::fs::metadata(&path) {
-        Ok(path.to_path_buf())
+        Ok(metadata) if metadata.is_dir() => Ok(path),
-    } else {
+        Ok(_) => Err(format!("{} is not a directory", path.display())),
-        Err(format!("{} is not a valid directory", path.display()))
+        Err(e) => Err(format!("Error accessing {}: {}", path.display(), e)),
     }
 }
 
@@ -37,7 +38,7 @@ fn parse_valid_dir(dir: &str) -> Result<PathBuf, String> {
 async fn main() -> std::io::Result<()> {
     let args = Args::parse();
 
-    let dir = args.dir;
+    let dir = Arc::new(args.dir);
     let sock = SocketAddr::new(args.ip, args.port);
 
     println!(
@@ -46,8 +47,9 @@ async fn main() -> std::io::Result<()> {
     );
 
     HttpServer::new(move || {
+        let dir = dir.clone();
         App::new().service(
-            actix_files::Files::new("/", dir.clone())
+            actix_files::Files::new("/", dir.as_ref())
                 .show_files_listing()
                 .prefer_utf8(true),
         )