pascal udp server

udp_server.pas

program UdpServer;

uses Sockets;


const
	UDPPackLen = 512;

var
	MasterSocket : Longint;
	Addr : TInetSockAddr;
	RecvLength : Int64;
	
	buff: String;
	FromAddr: sockaddr_in;
    FromAddrLen: Integer;

begin
	writeln ('Start program');

	MasterSocket := fpSocket (AF_INET, SOCK_DGRAM, 0);

	if MasterSocket < 0 then
	begin
		writeln ('Program exit: create socket error');
		Exit;
	end;

	Addr.sin_family := AF_INET;
  	Addr.sin_port := htons(5000);
	Addr.sin_addr.s_addr := INADDR_ANY;
	
	if fpbind (MasterSocket, @Addr, SizeOf (Addr)) < 0 then
	begin
		writeln ('Program exit: bind socket error');
   		Exit;
	end;

	while true do
	begin
	
		SetLength(buff, UDPPackLen);
	
		RecvLength := fprecvfrom (MasterSocket, @buff[1], Length(buff), 0, @FromAddr, @FromAddrLen);
		
		SetLength(buff, RecvLength);
		//ClientAddr := NetAddrToStr(FromAddr.sin_addr);
		//ClientPort := NToHs(FromAddr.sin_port);
		WriteLn(buff);
	end;
	

end.