linux show process port code example
Example 1: linux how to see ports in use
# Any of the following
sudo lsof -i -P -n | grep LISTEN
sudo netstat -tulpn | grep LISTEN
sudo lsof -i:22 # see a specific port such as 22
sudo nmap -sTU -O IP-address-Here
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