C# external tool for SSMS - Reading from stdin

class Program : WindowsFormsApplicationBase
{
    static Form1 mainForm = null;

    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    [STAThread]
    static void Main(string[] commandline)
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Program prog = new Program();
        prog.MainForm = mainForm = new Form1();
        prog.Run(commandline);
    }

    public Program()
    {
        this.IsSingleInstance = true;
    }

    protected override void OnStartupNextInstance(StartupNextInstanceEventArgs eventArgs)
    {
        base.OnStartupNextInstance(eventArgs);
        mainForm.Startup(eventArgs.CommandLine.ToArray());
    }
}

public void Startup(string[] commandLine)
    {
        string output = "";
        foreach (string arg in commandLine)
            output += arg + "n";

        label1.Text = output;
    }

    public Form1()
    {
        InitializeComponent();
        Startup(Environment.GetCommandLineArgs());
    }