pwd builting and pwd variable fix

src/main.rs

@@ -64,15 +64,14 @@ fn main(){
                     println!();
                 },
                 "cd" => {
-                    // default to '/' as new directory if one was not provided
                     let new_dir = args.peekable().peek().map_or(home_dir.clone(), |x| (*x).to_string());
                     let root = Path::new(&new_dir);
-                    pwd=root.clone().to_path_buf();
                     if let Err(e) = env::set_current_dir(&root) {
                         eprintln!("{}", e);
                     }
 
                     previous_command = None;
+                    pwd=env::current_dir().unwrap();
                 },
                 "pwd" => {
                     println!("{}", pwd.display());