For some of our long-running processes we use PHP. It makes total sense from our perspective, because we can re-use all our existing business logic from our main PHP web application. To make things more efficient, I recently started some work on using forks and have a couple of worker processes around.

His sample script makes use of the pcntl_fork and pcntl_wait functions in PHP to spawn off processes that will be closed off when no longer needed.

I recently wrote a little application that dumps a file across a forwarded port. [...] So when I first wrote it, I didn't know what I was doing and had never written socket code before, so it was a big procedural mess. Naturally I was keen to separate out my socket class into it's own package but this presented a problem: the controlling process needed to check the status but how could I decouple the process that instantiated the socket class from the socket code itself

So, he set about working up his class, hitting a few barriers along the way:

• Copy On Write issues with how PHP handles the variable for the forked process
• Interprocess Communication using Sockets using the socket_create_pair function
• a "Curious Interlude" about why you can share sockets between two processes

There's a example of it in action - a setup with a child process that's all set to count up and respond back with the current number to the managing script.