Sunday, April 13, 2014

Different ways to run scripts in node.js

Well now I have some weeks learning node, the easiest way to run a script is through  the node command, lets start with a simple script:

Save it as server.js If you want to run this script all you have to do is go to the directory where the script is and run the following command:

                           node server.js

Another way to run a script is through the npm command, it requires a file named package.json at the root of the project, this way is more sophisticated because in the package.json file you can specify a command to run a script, so you can have several commands each one mapped to a script.
Also it helps to configure dependencies, versions and a lot of other stuff, you can find more about the package.json configuration in the following link:

Well for the purpose of the blog the file package.json will be very simple just to show how it works, so it will contain the following:

In the file the start command is mapped to the server.js script, once the file is saved in the directory where sript is located the following command will run the script:

                          npm start

Another way to run a script is with the help of packages one of them is nodemon (, it stands for node monitor.

The description of nodemon says that it is a utility that will monitor for any changes in your source and automatically restart your server. Perfect for development. Using nodemon instead of node to run your code, and now your process will automatically restart when your code changes.

To install nodemon jus run the following command:

                         npm install -g nodemon

The -g means that it will install nodemon in a global way, you don't have to install it for every project.

Once installed you can see it working, just replace the node command for nodemon and run the script:

                         nodemon server.js

To see it working type the address in your browser and see the output, then modify the script to output instead "Hello world" to something else, reload the browser and see that the changes are reflect, so this is the big advantage of using nodemon you don't have to waste any time running the scripts while developing them.

Another package that does the same as nodemon is run (, install it just like nodemon:

                         npm install -g run

Then run the script with the run command

                         run server.js

Do the same exercise go the address  see the output and modify the script, reload the page and see the changes.

So far in my way to node these are the different ways to run scripts, I hope you can learn something new from it.