Linux | How to find a program running on a particular port

I was having problem starting the apache, because ubuntu system auto installs the apache2 web server and it starts on the system startup. And every thing is messed up. I know the concepts of what was happening there, but I forgot the commands. So I am writing this post to find it if I ever again ran into the same problem.

sudo netstat | grep 80

Kill pid

The first command will list the programs and their ids that have patterns that match 80, which might be their name or most likely port numbers for netstat command.

Then kill the command with pid command;

them start the lampp again.

sudo /opt/lampp/lampp restart

If you want to see the list of programs you are running 

ps 

ps -nlp 

The second command will show all the programs that are running on the system.