static void Main(string[] args) { args = new string[3] { "c:\\BigFile.txt", "c:\\BigFile_out.txt", "10485760" }; if (args.Length != 3) { Console.WriteLine("Usage: HugeFileSort <input> <output> <maxsize>"); return; } long size; if (!long.TryParse(args[2], out size)) { Console.WriteLine("Third parameter must be a number"); return; } var hfs = new HugeFileSort { MaxFileSize = size, Comparer = StringComparer.CurrentCultureIgnoreCase }; Stopwatch sw = Stopwatch.StartNew(); try { hfs.Sort(args[0], args[1]); Console.WriteLine("Operation completed in {0} msec", sw.ElapsedMilliseconds); } catch (Exception ex) { Console.WriteLine(ex.ToString()); Console.ReadKey(); } }