Bash function to check what is running on a specified port.

whatisonport.sh

# load into your path and run `whatisonport 5432`
whatisonport() {
  echo "lsof results - "
  echo "$(sudo lsof -i :$1)"
  echo " "
  echo "fuser results - "
  echo "$(sudo fuser $1/tcp)"
  echo " "
  echo "netstat results - "
  echo "$(sudo netstat -ltnp | grep -w :$1)"
  echo " "
}