port already in use linux 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: find out which procses is using port linux

sudo lsof -i:<port_number>

Example 4: port 8080 already in use

netstat -ano | findstr 8080

Example 5: django port 8000 already in use

sudo fuser -k 8000/tcp

Example 6: check what ports are open linux

## if you use linux
sudo ss -tulw