Question

I have the following situation:

function Mach3Code(Str: String): String;
 var StrOut: String;
 begin
   StrOut := '';

   try
     IdTelnet1.Connect();
     IdTelnet1.Write(Str);

     StrOut := ''; // assign here return output;

   finally
     IdTelnet1.Disconnect;
   end;

   Result := StrOut;

 end;

On the line “StrOut := ”;” I need to get the text output of the server (which is a tcp server, written in vc 2008 by me as Mach3 plugin).

Normally, the client sends “COMMAND1” and the server replies with “ANSWER1#” or something like this. I need the code to wait for the answer and then return it, synchronously, so I can do something like:

StrResult := Mach3Code('G0X300Y200');

and read what the server part has sent to me.

any ideas how I can solve this problem?

Answer 1

TIdTelnet is an asynchronous componnt, it is not suited for what you are attempting to do. Unless you are dealing with the actual Telnet protocol, then you should use TIdTCPClient instead:

function Mach3Code(const Str: String): String;
begin
  Result := '';
  try
    IdTCPClient1.Connect();
    IdTCPClient1.WriteLn(Str);
    StrOut := IdTCPClient1.ReadLn('#');    
  finally
    IdTCPClient1.Disconnect;
  end;
end;