# Introduction

In a previous article we learned about [Creating a PHP Daemon Service](https://beta.nomadphp.com/blog/50/creating-a-php-daemon-service). Now we are going to learn how to use methods to perform IPC - Inter-Process Communication - to communicate with daemon processes.

# Message Queues

In the world of UNIX, there is an incredible variety of ways to send a message or a command to a daemon script and vice versa. But first I want to talk only about message queues - "System V IPC Messages Queues".

A long time ago I learned that a queue can be either in the System V IPC implementation, or in the POSIX implementation. I want to comment only about the System V implementation, as I know it better.

Lets get...