How to monitor PHP work in the SSH console?

Question

linux

Hello!
There is a PHP script that receives GET and POST requests (API of one of the services). I want to believe that there is a way to see online what a PHP file returns in response to API requests. If this is not possible, then tell me the most modern way to track the results of the PHP file.

Answer 1

Run as root (well, or via sudo) and watch the traffic:
This is the most banal example for tcpdump with a minimum number of options. If you need to add or change something (port, for example) - there are a lot of examples on the net.