How to find and kill a port

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This is a simple approach which we need on daily basis which is find and kill a port.

Following are the steps to find and kill the port.

1. You should find the process id which is known as pid using the port as follows.

sudo lsof -i :<port_id>

Following is a sample output for sudo lsof -i :3000

COMMAND      PID USER   FD   TYPE  DEVICE SIZE/OFF NODE NAME
docker-pr 299618 root    4u  IPv4 3950094      0t0  TCP *:3000 (LISTEN)

2. Then get the pid which is bolded in the above example and kill it as follows. kill [option] <pid>

kill -15 299618   // -15 for give time to safely cleanup and die.

or you can simply kill it without give time to cleanup.

kill -9 299618

Okay what if I don’t know what is the port id? Then list all the ports and find it as follows.

sudo lsof -nP -iTCP -sTCP:LISTEN 

Important: If you don’t know the port but you know process name or anything you can simply use grep using pipe and filter out as follow.

sudo lsof -nP -iTCP -sTCP:LISTEN | grep mysqld

Above will filter processes with mysqld as follows.

Hope this will be helpful.

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