using PERLEZHANDLE = System.IntPtr;

class MyClass
{
  [DllImport("PerlEz.dll")]
  private static extern PERLEZHANDLE PerlEzCreateOpt(string lpFileName, string lpOptions, string lpScriptOpts);

  [DllImport("PerlEz.dll")]
  private static extern int PerlEzCall1(PERLEZHANDLE hHandle, string lpFunction, [MarshalAs(UnmanagedType.LPStr)] StringBuilder lpBuffer, UInt32 dwBufSize, string lpFormat, IntPtr IntPtr1);

  // Callback Function
  public delegate string Callback();
  static public string foo()
  {
    return "Hello C# World.";
  }

  [STAThread]
  static void Main(string[] args)
  {
    PERLEZHANDLE PerlHandle = PerlEzCreateOpt("test.pl", null, null);

    // Create a function pointer to the callback
    Callback cb = new Callback(foo);
    IntPtr   fp = System.Runtime.InteropServices.Marshal.GetFunctionPointerForDelegate(cb);

    // Invoke the perl function
    StringBuilder Response = new StringBuilder(1024);
    int ReturnCode = PerlEzCall1(PerlHandle, "test", Response, System.Convert.ToUInt32(Response.Capacity), "i", fp);

    if(ReturnCode == 5)
      Console.WriteLine("Exception!");
    else
      Console.WriteLine("Response: " + Response.ToString());
  }

}

##</code><code>##

#use strict;
require DynaLoader;

sub test
{
  my ($a, $b, $c, $d) = @_;
   
  # Convert the SV into a CV (...I hope)
  my $code_ref = DynaLoader::dl_install_xsub("main::foo", $a);
  
  # An exception occurs on the next line.
  return "Hello Perl World." . $code_ref->();
}