node.js express socket.io port 3000 in use

Question

I\'ve been following this(http://socket.io/get-started/chat/) tutorial on how to make a simple chat application using socket.io.

I tried to however use Express to create

Answer 1

Try running:

netstat -anp tcp | grep 3000

This should show you the name of the process that is using port 3000. Here's another issue on StackOverflow that covers this issue in more depth.

Answer 2

Similar to answer above to not use npm start.

I was using nodemon and with expressjs and expressjs generator. I was using nodemon to execute npm start, while npm start itself execute node ./NodeApp/bin/www

So i edited to make nodemon to execute node ./NodeApp/bin/www by itself and that error go away.

Conclusion

Before

package.json

"scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node ./NodeApp/bin/www",
    "build": "webpack --watch",
    "dev": "nodemon --exec npm start"
},

After

"scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "webpack --watch",
    "dev": "nodemon --exec node ./NodeApp/bin/www"
},

So now I run my sever with npm run dev and no more errors.