readline.cs

string[] history = new string[] { "ls -a", "dotnet run", "git init" };
ReadLine.AddHistory(history);

ReadLine.AutoCompletionHandler = (t, s) =>
{
    if (t.StartsWith("git"))
        return new string[] { "init", "clone", "pull", "push" };
    else
        return null;
};

string input = ReadLine.Read("(prompt)> ");
Console.Write(input);