6.1 Introduction

The Linux IPC (Inter-process communication) facilities provide a method for multiple processes to communicate with one another. There are several methods of IPC available to Linux C programmers:

• Half-duplex UNIX pipes
• FIFOs (named pipes)
• SYSV style message queues
• SYSV style semaphore sets
• SYSV style shared memory segments
• Networking sockets (Berkeley style) (not covered in this paper)
• Full-duplex pipes (STREAMS pipes) (not covered in this paper)

These facilities, when used effectively, provide a solid framework for client/server development on any UNIX system (including Linux).