Stevens introduces the reader to the internal structures of Posix interprocess communication (IPC) and System V (SysV) IPC; pipes and first in, first outs (FIFOs); message queues; how to lock and unlock files and records; semaphores; shared memory; and remote procedure calls (RPCs). He explains the difference between the Posix and SysV implementations of semaphores, message queues, and shared memory. There are also plenty of notes and examples for the reader.
This book is invaluable for programmers because it explains all of those little "gotchas" that always seem to pop up. In addition, the explanations of the differences between Posix IPC and SysV IPC really help readers decide which version they'd like to use for their applications. --Doug Beaver