A TCP API server

At this point, the chapter has covered the minimum networking components necessary to create client and service programs. The remainder of the chapter will discuss different versions of a server that implement a monetary currency information service. The service returns ISO 4217 monetary currency information with each request. The intent is to show the implications of creating networked services, along with their clients, using different application-level protocols.

Earlier we introduced a very simple server to demonstrate the necessary steps required to set up a networked service. This section dives deeper into network programming by creating a TCP server that scales to handle many concurrent connections. The server code presented in this section has the following design goals:

• Use raw TCP to communicate between client and server
• Develop a simple text-based protocol, over TCP, for communication
• Clients can query the server for global currency information with text commands...