19.5. System V Messages
System V messages are one of three methods of inter-process communication provided by System V operating systems. They allow processes to communicate via formatted messages. Processes place messages of a fixed length in the queues of other processes.
A complete discussion of System V messages is beyond the scope of this text. There are plenty of resources for learning more about them. I recommend Unix Network Programming by W. Richard Stevens, published by Prentice Hall. The second edition was published in 1997 as two volumes.
Listings 19.18 and 19.19 implement a simple server that makes strings uppercase using System V messages. The server waits for clients to place messages in its queue. The server responds by placing ...