unix find process running on port code example

Example 1: linux query port use by pid

$ sudo netstat -nlp | grep :80
tcp  0  0  0.0.0.0:80  0.0.0.0:*  LISTEN  125004/nginx

Example 2: linux check what process is using port

$ netstat -ltnp | grep -w ':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