Hello Monks,

I do not know if the following is possible, but if anyone has done something similar I would appreciate any help they could offer.

I am trying to writing a C# program that calls Perl subs, that in turn call functions in the C# program. I found an example of something similar online (OpenHoldemBot, line 399), but I have been unable to call the function pointer without causing an exception.

Any Ideas?

MyClass.cs:

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 l
+pFunction, [MarshalAs(UnmanagedType.LPStr)] StringBuilder lpBuffer, U
+Int32 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.GetFunctionPo
+interForDelegate(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());
  }

}

[download]

test.pl:

#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->();
}

[download]

In reply to C# calling Perl calling C# by rich41

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