linux list processes by 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: process runninng on particular port

sudo ss -lptn 'sport = :80'

Example 3: bash list process on port

sudo lsof -i:3000
#Just change the port 3000