PowerArgs.StdConsoleProvider.ReadALineOfConsoleOutput C# (CSharp) Method

        public static string ReadALineOfConsoleOutput(int y)
        {
            if (y < 0) throw new Exception();
            IntPtr stdout = GetStdHandle(STD_OUTPUT_HANDLE);

            uint nLength = (uint)Console.WindowWidth;
            StringBuilder lpCharacter = new StringBuilder((int)nLength);

            // read from the first character of the first line (0, 0).
            COORD dwReadCoord;
            dwReadCoord.X = 0;
            dwReadCoord.Y = (short)y;

            uint lpNumberOfCharsRead = 0;

            if (!ReadConsoleOutputCharacter(stdout, lpCharacter, nLength, dwReadCoord, out lpNumberOfCharsRead))
                throw new Win32Exception();

            var str = lpCharacter.ToString();
            str = str.Substring(0, str.Length - 1).Trim();

            return str;
        }

        /// <summary>
        /// Before PowerArgs parses the args, this hook inspects the command line for the indicator and if found
        /// takes over the command line and provides tab completion.
        /// </summary>
        /// <param name="context">The context used to inspect the command line arguments.</param>
        public override void BeforeParse(ArgHook.HookContext context)
        {
            if (CompletionSourceType != null &&
                CompletionSourceType.GetInterfaces().Contains(typeof(ITabCompletionSource)) == false &&
                CompletionSourceType.GetInterfaces().Contains(typeof(ISmartTabCompletionSource)) == false)
            {
                throw new InvalidArgDefinitionException("Type does not implement ITabCompletionSource or ISmartTabCompletionSource: " + CompletionSourceType.FullName);
            }

            if (context.Definition.IsNonInteractive)
            {
                this.REPL = false;
                return;
            }
            if (Indicator == "" && context.CmdLineArgs.Length != 0)
            {
                this.REPL = false;
                return;
            }
            if (Indicator != "" && (context.CmdLineArgs.Length != 1 || context.CmdLineArgs[0] != Indicator))
            {
                this.REPL = false;
                return;
            }

            if (REPL && ShowREPLWelcome)
            {
                ConsoleString.Empty.WriteLine();
                var message = REPLWelcomeMessage.Replace("{{Indicator}}", REPLExitIndicator);
                ConsoleString.WriteLine(message, ConsoleColor.Cyan);
                ConsoleString.Empty.WriteLine();
                ConsoleString.Write(Indicator + "> ", ConsoleColor.Cyan);
                ShowREPLWelcome = false;
            }
            else if (REPL)
            {
                ConsoleString.Write(Indicator + "> ", ConsoleColor.Cyan);
            }
            else
            {
                // This is a little hacky, but I could not find a better way to make the tab completion start on the same lime
                // as the command line input
                try
                {
                    var lastLine = StdConsoleProvider.ReadALineOfConsoleOutput(Console.CursorTop - 1);
                    Console.CursorTop--;
                    Console.WriteLine(lastLine);
                    Console.CursorTop--;
                    Console.CursorLeft = lastLine.Length + 1;
                }
                catch (Exception)
                {
                    Console.WriteLine();
                    Console.Write(Indicator + "> ");
                }
            }

            PowerArgsRichCommandLineReader reader = new PowerArgsRichCommandLineReader(context.Definition, LoadHistory());

            IHighlighterConfigurator customConfigurator;

            if (HighlighterConfiguratorType.TryCreate <IHighlighterConfigurator>(out customConfigurator))
            {
                customConfigurator.Configure(reader.Highlighter);
            }

            var newCommandLineString = reader.ReadLine().ToString();
            var newCommandLineArray  = Args.Convert(newCommandLineString);

            if (REPL && newCommandLineArray.Length == 1 && string.Equals(newCommandLineArray[0], REPLExitIndicator, StringComparison.OrdinalIgnoreCase))
            {
                throw new REPLExitException();
            }

            if (REPL && newCommandLineArray.Length == 1 && newCommandLineArray[0] == "cls")
            {
                ConsoleProvider.Current.Clear();
                throw new REPLContinueException();
            }

            else if (REPL && newCommandLineArray.Length == 0 && string.IsNullOrWhiteSpace(REPLExitIndicator) == false)
            {
                throw new REPLContinueException();
            }

            context.CmdLineArgs = newCommandLineArray;
            AddToHistory(newCommandLineString);
        }