Determine the process pid listening on a certain port

Question

As the title says, I'm running multiple game servers, and every of them has the same name but different PID and the port number. I would like to match the PID of the server which is listening on certain port, and then I would like to kill this process. I need that in order to complete my bash script.

Is that even possible? Because it didn't find yet any solutions on the web.

score 157 · Answer 1 · answered Dec 29 '12 at 13:25

157

Short version which you can pass to kill command:

lsof -i:80 -t

answered Dec 29 '12 at 13:25

Laurynas

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This also includes processes that are _connected_ on that port. `lsof -i4TCP:80 -sTCP:LISTEN -t` is probably what you want, instead. – Nevir Mar 26 '16 at 21:18
Exactly what I was looking for. I wanted to kill a process by searching for the port it is running at. – mythicalcoder May 25 '17 at 13:08
@Nevir what do you mean by " also includes processes that are connected on that port"? Can you please explain? – kishorer747 Jul 05 '17 at 06:22
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`kill -9 \`lsof -i:80 -t\`` for ease of copying – bmjrowe Aug 13 '19 at 10:59

score 131 · Accepted Answer · edited Dec 14 '21 at 15:33

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The -p flag of netstat gives you PID of the process:

netstat -l -p

*use sudo if showing - instead of PID

Edit: The command that is needed to get PIDs of socket users in FreeBSD is sockstat. As we worked out during the discussion with @Cyclone, the line that does the job is:

sockstat -4 -l | grep :80 | awk '{print $3}' | head -1

edited Dec 14 '21 at 15:33

Noam Yizraeli

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answered Mar 24 '12 at 23:30

stanwise

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`netstat: 80: unknown or uninstrumented protocol` used the `80` (nginx) port for testing purpoes. Not worked. – Cyclone Mar 24 '12 at 23:36
`netstat -l -p 80` , when I do `netstat -l -p` I'm getting the manual: http://pastebin.com/raw.php?i=q9jeQSBj – Cyclone Mar 24 '12 at 23:48
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try `netstat -nlp | grep :80` instead – stanwise Mar 24 '12 at 23:51
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`netstat: option requires an argument -- p` – Cyclone Mar 24 '12 at 23:54
Hmm, you have different `-p` option. Try `sockstat -4 -l` – stanwise Mar 25 '12 at 00:00
let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/9265/discussion-between-stanwise-and-cyclone) – stanwise Mar 25 '12 at 00:09
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@jasonbrittain On Cygwin, windows native `netstat` is called. It has other syntax. – stanwise Sep 15 '12 at 20:33
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this answer is wrong: netstat: option requires an argument -- p – Good Person May 10 '14 at 01:21
On OS X here. The -p flag is used to specify the protocol filter in the native netstat. – Abraham Philip Mar 14 '17 at 04:42
I think you're looking for `-b` – Nathan Dortman Aug 11 '17 at 15:13
For processes run from other users the output includes the process, but won't include its PID. I had to use `sudo netstat ...` – mirelon Jun 01 '18 at 12:26
@stanwise You can turn this `grep :80 | awk '{print $3}'` into a single statement like so: `awk '/:80/{print $3}'`. I am sure you probably know this now but I think it'll be good for the others searching who stumble upon this to know. – Aguevara Apr 26 '19 at 12:26

gavenkoa · Answer 3 · 2017-12-30T12:17:48.233

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netstat -p -l | grep $PORT and lsof -i :$PORT solutions are good but I prefer fuser $PORT/tcp extension syntax to POSIX (which work for coreutils) as with pipe:

pid=`fuser $PORT/tcp`

it prints pure pid so you can drop sed magic out.

One thing that makes fuser my lover tools is ability to send signal to that process directly (this syntax is also extension to POSIX):

$ fuser -k $port/tcp       # with SIGKILL
$ fuser -k -15 $port/tcp   # with SIGTERM
$ fuser -k -TERM $port/tcp # with SIGTERM

Also -k is supported by FreeBSD: http://www.freebsd.org/cgi/man.cgi?query=fuser

edited Dec 30 '17 at 12:17

answered Jan 31 '14 at 14:35

gavenkoa

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fuser us neater and concise – Dawoodjee May 07 '19 at 10:58

score 11 · Answer 4 · answered Mar 24 '12 at 23:29

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netstat -nlp should tell you the PID of what's listening on which port.

answered Mar 24 '12 at 23:29

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`netstat: 80: unknown or uninstrumented protocol` used the `80` (nginx) port for testing purpoes. Not worked. – Cyclone Mar 24 '12 at 23:39

score 4 · Answer 5 · answered Apr 30 '19 at 08:51

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Syntax:

kill -9 $(lsof -t -i:portnumber)

Example: To kill the process running at port 4200, run following command

kill -9 $(lsof -t -i:4200)

Tested in Ubuntu.

answered Apr 30 '19 at 08:51

Debashish Sen

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score 3 · Answer 6 · answered Mar 17 '15 at 18:31

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Since sockstat wasn't natively installed on my machine I hacked up stanwise's answer to use netstat instead..

netstat -nlp | grep -E "[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\:2000" | awk '{print $7}' | sed -e "s/\/.*//g""

answered Mar 17 '15 at 18:31

dafky2000

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score 3 · Answer 7 · answered Mar 28 '17 at 23:48

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I wanted to programmatically -- using only Bash -- kill the process listening on a given port.

Let's say the port is 8089, then here is how I did it:

badPid=$(netstat --listening --program --numeric --tcp | grep "::8089" | awk '{print $7}' | awk -F/ '{print $1}' | head -1)
kill -9 $badPid

I hope this helps someone else! I know it is going to help my team.

answered Mar 28 '17 at 23:48

Glavin001

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Here is the function I use to do it: `function kill-listener { lsof -i:$1 -t | xargs kill -9 }` Using your example of port 8089: `kill-listener 8089` – Hurricane Hamilton Jun 21 '17 at 14:00

score 2 · Answer 8 · answered Feb 24 '18 at 13:42

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on windows, the netstat option to get the pid's is -o and -p selects a protocol filter, ex.: netstat -a -p tcp -o

answered Feb 24 '18 at 13:42

Jan Wilmans

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Determine the process pid listening on a certain port

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