TCP/IP Sockets in C, 2nd Edition

Chapter 5 Sending and Receiving Data

Typically, you use sockets because your program needs to provide information to, or use information provided by, another program. There is no magic: any programs that exchange information must agree on how that information will be encoded—represented as a sequence of bits—as well as which program sends what information when, and how the information received affects the behavior of the program. This agreement regarding the form and meaning of information exchanged over a communication channel is called a protocol; a protocol used in implementing a particular application is an application protocol. In our echo example from the earlier chapters, the application protocol is trivial: neither the client’s nor the ...