see if port is in use code example
Example 1: linux how to see ports in use
sudo netstat -tulpn | grep LISTEN
sudo lsof -i:22 # see a specific port such as 22
Example 2: check what ports are open linux
## if you use linux
sudo ss -tulw
sudo netstat -tulpn | grep LISTEN
sudo lsof -i:22 # see a specific port such as 22
## if you use linux
sudo ss -tulw