see what port a process is using code example

Example 1: find out which procses is using port linux

sudo lsof -i:<port_number>

Example 2: process runninng on particular port

sudo ss -lptn 'sport = :80'

Example 3: cli check what is listening on port

lsof -i tcp:53 #Check what is listening on port 53
lsof -t -i tcp:53 #Return the process PID listening on port 53