![PHP IPC with Daemon Service using Message Queues, Shared Memory and Semaphores](https://images.ctfassets.net/vzl5fkwyme3u/4ULcw2rCysGcSGOAi2uKOk/450013591b84069c5536663430536714/AdobeStock_200383770.jpeg?w=1000)
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.