Beej's Guide to Unix Interprocess Communication

Intro

However, when you start fork()'ing processes, you immediately start to think of the neat multi-user things you could do if the processes could talk to each other easily. So you try making a global array and then fork()'ing to see if it is shared. (That is, see if both the child and parent process use the same array.) Soon, of course, you find that the child process has its own copy of the array and the parent is oblivious to whatever changes the child makes to it.

How do you get these guys to talk to one another, share data structures, and be generally amicable? This document discusses several methods of Interprocess Communication (IPC) that can accomplish this, some of which are better suited to certain tasks than others.

Audience

As with Beej's Guide to Network Programming Using Internet Sockets, these documents are meant to springboard the aforementioned user into the realm of IPC by delivering a concise overview of various IPC techniques. This is not the definitive set of documents that cover this subject, by any means. Like I said, it is designed to simply give you a foothold in this, the exciting world of IPC.

Platform and Compiler

Specific Documents:

• A fork() primer
• Signals
• Pipes
• FIFOs (Named Pipes)
• File locking
• System V IPC (which works on most Unix flavors, anyway...)
  • Message Queues
  • Semaphores
  • Shared Memory
• Memory Mapped Files
• Unix Sockets
• More resources