Mastering PHP 7

Process control

Building CLI applications quite often implies working with the system processes. PHP provides a powerful process control extension called PCNTL. The extension allows us to handle process creation, program execution, signal handling, and process termination. It only works on Unix-like machines, where PHP is compiled with the --enable-pcntl configuration option.

To confirm that PCNTL is available on our system, we can execute the following console command:

php -m | grep pcntl

Given the power it bares, the use of the PCNTL extension is discouraged in production web environments. Writing PHP daemons scripts for command-line applications is what we want to use it for.

To start putting things into perspective, let's go ahead and ...