View Mac port occupancy and kill the process

View the port command occupancy

sudo lsof -i :9000

After the colon is the port number you want to view.

TheEternityZhang-MacBook:project zhtony$ sudo lsof -i :8080
Password:
COMMAND   PID   USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
java    27374 zhtony  221u  IPv6 0x3a877ef28e41f1b3      0t0  TCP *:http-alt (LISTEN)
TheEternityZhang-MacBook:project zhtony$ kill -9 27374

Kill the processes that are currently occupied by the port number

There is a table named head of a PID, this column it means that the process is currently occupied port.

sudo kill -9 27374