Батник удаления одинаковых строк из текстовых файлов

/*
@echo off && cls
%WinDir%\Microsoft.NET\Framework\v2.0.50727\csc.exe /nologo /out:"%~0.exe" %0
"%~0.exe" %1
del "%~0.exe"
exit
*/

//8 oct 2012 @ 18:36
//metaspamer.blogspot.com

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace spicemustflow_sortcleaner
{
    class Program
    {
        static string GetFilename(string nameWithoutExtension, bool uniq)
        {
            int n = 1;
            string outputFile = string.Empty;
            while (true)
            {
                outputFile = string.Format("{0}_{1}{2}.txt",
                    nameWithoutExtension, uniq ? "uniques" : "duplicates",
                    n > 1 ? n.ToString() : string.Empty);
                if (File.Exists(outputFile)) n++;
                else break;
            }
            return outputFile;
        }

        static void Main(string[] args)
        {
            string path = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location) + "\\";
            string[] filelist = null;
            if (args.Length == 0) filelist = Directory.GetFiles(path, "*.txt", SearchOption.TopDirectoryOnly);
            else filelist = args;

            foreach (string filename in filelist)
            {
                Encoding enc = Encoding.Default;
                using (FileStream fs = File.OpenRead(filename))
                {
                    byte[] data = new byte[3];
                    while (fs.Read(data, 0, data.Length) > 0)
                        if (data[0] == 0xef && data[1] == 0xbb && data[2] == 0xbf)
                        {
                            enc = Encoding.UTF8;
                            break;
                        }
                        else
                        {
                            enc = Encoding.GetEncoding(1251);
                            break;
                        }
                }

                Console.Write("loading {0}..\n", filename);
                string[] input = File.ReadAllLines(filename, enc);
                if (input.Length > 0)
                {
                    Console.Write("sorting..\n");
                    Array.Sort(input);
                    List<string> uniques = new List<string>();
                    List<string> duplicates = new List<string>();
                    Console.Write("deleting duplicates..\n");
                    uniques.Add(input[0]);
                    for (int i = 1; i < input.Length; i++)
                        if (input[i] != input[i - 1])
                            uniques.Add(input[i]);
                        else
                            duplicates.Add(input[i]);

                    Console.Write("\nsaving..\n");
                    File.WriteAllLines(path + GetFilename(Path.GetFileNameWithoutExtension(filename), true), uniques.ToArray(), enc);
                    File.WriteAllLines(path + GetFilename(Path.GetFileNameWithoutExtension(filename), false), duplicates.ToArray(), enc);
                    Console.Write("\n\n");
                }
            }
        }
    }
}