Linux (ubuntu) check which process uses a port

To see which process is using a certain port we will use netstat command , if not installed , install net-tools  :

#for ubuntu/debian users
sudo apt install net-tools

let check which process is using port 80:

sudo netstat -ltnp | grep :27017

the result is :

tcp  0   0   127.0.0.1:27017   0.0.0.0:*  LISTEN    2481/mongod

we see that the port 27017 is used by mongod with pid 2481

get some information about the process using ps command

ps -aux | grep 2481
mongodb  2481  0.6  0.4 1519600 100704 ?  Ssl  05:44   1:04 /usr/bin/mongod --config /etc/mongod.conf