Borland Socket Server Code As Seen

Server will get so many hits from different clients, and then server has to identify each client uniquely to reply every request.

To achieve this we use ip address of client (32 bit) port number (16 bit) of the process.

To know the success message we here printing that time and date.

You can also see we are assigning ipOfServer AFINET, represents that this argument related to Internet IP addresses.

But it may eat up all CPU processing, to avoid that we have written sleep(1), which server went to sleep for 1 sec.

If ever i get a chance to meet you my life would be complete.

It helps in reducing errors such as Address already in use and helps is reuse of address and port.

Now I want to know how to make a simple chat program using tcpip and a native Linux app.

In fact, after you have a working DataSnap server, you only need to run it to enable it to register itself (so you can locate it and connect to it from a DataSnap client).

However, DataSnap can also employ a third protocol: TCPIP (plain sockets).

This is done by using the TSocketConnection component (the third of the Connection components available on the DataSnap tab of the Component Palette from CBuilder 6 Enterprise).

If you dont have an NT domain server available on your network, you should probably not try to use DCOM at all and instead should use plain TCPIP.

A socket connection will work even if no NT server is in the equation, and it is usually much easier to set up than a DCOM connection.

However, security is much more difficult to enforce on a socket connection (unlike the TWebConnection component, for example).

You can easily convert either SimpleDataSnapClient or DataSnapClient into a TCPIP application.

You dont even need to make any changes to your DataSnap servers to make it work.

To get started building your sockets-based DataSnap program, run the ScktSrvr.exe program found in the CBuilder6Bin directory on the server machine.

This program must be running on the server or this system will not work.

Note that ScktSrvr.exe can either be run as a normal application or be used as an NT service (using the -install and -uninstall command-line parameters).

Drop a TSocketConnection component from the DataSnap page of the Component Palette on the main form of the DataSnapClient application.

Set its Address property to the IP address of the machine where the DataSnapServer application resides.

This can be a remote machine or your current machine (such as localhost ).

Fill in the ServerName property, just as you did in the DCOM example earlier in this chapter, by dropping down the ServerName combo box and selecting the DataSnapServer.CustomerOrders DataSnap Server.

You should now be able to test your connection by setting the Connected property of the TSocketConnection component to true.

As I explained earlier, you should not leave the Connected property set to true at design time.

Borland Socket Server Code As Seen

Assuming you have dropped down a TSocketConnection component on the form and set its ServerName property correctly, you can drop a new TButton component, set its Name property to ButtonSocket, Caption to Socket, and write the event handler code as seen in Listing 20.2: Listing 21.2 SocketConnection to Remote Machine void fastcall TForm1::ConnectTCPIP1Click(TObject Sender) AnsiString S; if (InputQuery(Enter Machine Name or IP-Address:, Machine NameIP-Address, S)) SocketConnection1-Address S; ClientDataSet1-RemoteServer SocketConnection1; ClientDataSet1-Active true; When the user clicks on the Socket button, he is prompted for the IP address of the machine where the server resides.

It then changes the RemoteServer property of the TClientDataSet so that it no longer points at the TDCOMConnection component, but at that TSocketConnection component.

Finally, it sets the Active property of the TClientDataSet to true.

Setting the Active property to true will automatically cause the TSocketConnection.Connected property to be set to true as well, as youve seen earlier.

At this stage, you should be fully connected to your server and viewing your data.

This approach will work equally well whether the server is on the same machine or on a remote machine.

Furthermore, you dont need an NT domain server or even an NT server, though I always recommend that you use one when working with DataSnap.

Note that the DataSnap server does not have to be changed to connect to a client using DCOM or sockets (TCPIP).