Socket Programming
lazarus / 1-Linux

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thaimann · 2005-06-26 17:03

I have been playing around with socket programming with Lazarus.  I
hjave used the simpleserver/simpleclient from the following web page:

http://www.bastisoft.de/pascal/pasinet.html

Now I can compile and run the simpoleserver example with fpc and it
runs correctly.

But if I run it as a thread, two things happen.

1.  It won't run unless I run it as root.
2.  When running as root, it won't accept any connecftions.

Any clue as to why this doesn't work?

My thread is defined as follows:

Procedure TSockThread.Execute;
const
   ListenPort : Word = $AFFE;
   MaxConn = 1;

var
   lSock, uSock : LongInt;
   sAddr : TInetSockAddr;
   Len : LongInt;
   Line : String;
   sin, sout : Text;

begin
   lSock := Socket(af_inet, sock_stream, 0);
   if lSock = -1 then SockError('Socket: ');

   with sAddr do
   begin
      Family := af_inet;
      Port := htons(ListenPort);
      Addr := 0;
   end;

   if not Bind(lSock, sAddr, sizeof(sAddr)) then SockError('Bind: ');
   if not Listen(lSock, MaxConn) then SockError('Listen: ');

   repeat
      Say('Waiting for connections...');
      Len := sizeof(sAddr);
      uSock := Accept(lSock, sAddr, Len);
      if uSock = -1 then SockError('Accept: ');
      Say('Accepted connection from ' + AddrToStr(sAddr.Addr));

      Sock2Text(uSock, sin, sout);

      Reset(sin);
      Rewrite(sout);
      Writeln(sout, 'Welcome, stranger!');
      while not eof(sin) do
      begin
         Readln(sin, Line);
         if Line = 'close' then break;
         Writeln(sout, Length(Line));
      end;

      Close(sin);
      Close(sout);
      Shutdown(uSock, 2);
      Say('Connection closed.');
   until False;
End;

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Almindor · 2005-07-04 08:39

I don't know why it makes problems but I know that using write[ln] and
textfiles as bufferes was buggy. Also fpc internaly uses winsock 1 in
windows. I'd advise you to get winsock2 header and use recv/send.

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fatg · 2005-07-05 23:22

Or maybe try a higher-level implementation of sockets, like Synapse?

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Anonymous · 2005-07-27 15:25

I highly recommend Synapse, it totally rocks and has great support
built in for SSL, super easy to use also.

Quote from: "fatg"Or maybe try a higher-level implementation of
sockets, like Synapse?