using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
    class Program
    {

        public static void Main(string[] args)
        {
            if (args.Length < 2 )
            {
            Console.WriteLine(value: "ERROR: args = null please provide a path and a file specification to search for.");
            Console.WriteLine(value: "Example: list c:\\ *.dll");
        }
        else
            {
               DirectoryInfo testdr = new DirectoryInfo(path: args[0]);
               WalkDirectoryTree(testdr, searchname: args[1]);
            }
        }
    
    public static void WalkDirectoryTree(DirectoryInfo dr, string searchname)
    {
        System.IO.FileInfo[] files = null;
        DirectoryInfo[] subDirs = null;
        try
        {
            files = dr.GetFiles(searchname);
        }
        catch (Exception ex)
        {
            //Console.WriteLine(ex.Message);
        }

        if (files != null)
        {
            foreach (FileInfo fi in files)
            {
                string dir = fi.DirectoryName;
                string file = fi.ToString();
                Console.WriteLine(value: dir + file);
            }
            subDirs = dr.GetDirectories();

            Parallel.ForEach(subDirs, dir => WalkDirectoryTree(dir, searchname));
        }
    }

    public override bool Equals(object obj)
    {
        return base.Equals(obj);
    }

    public override int GetHashCode()
    {
        return base.GetHashCode();
    }

    public override string ToString()
    {
        return base.ToString();
    }
}