How to Pass a Command Line Argument in NodeJS?

Question

I have a file structure, which I will enumerate for you in a moment. I have a web server, that initiates a command line process on a button press. I want to add in the option to run the server in a headless manner, using a command line argument. Is this the way I should be doing this? Here is my Project Structure.

/models
 /model1
 /model2
 /model3
/routes
 /index
 /test
 /users
 /credentials
 /adduser
/views
 /same as routes. Route 'test' has no layout.

in index, or '/', I have a function, which takes several parameters, and is initiated via clicking a button on the index page. We are then forwarded through 'test/run', and render the 'index' view. The process continues to run in the terminal. I will now post an example of the function.

 router.post('/run', ensureAuthenticated, function(req, res){
 return res.redirect('/test/running')
 });
 // Get Homepage
 router.get('/running', ensureAuthenticated, function(req, res){
 console.log(res.locals.user);
 // console.log(app.locals.user);
 const var1 = res.locals.user.username;
 const var2 = res.locals.user.username;
 const var3 = res.locals.user.username;
 const var4= res.locals.user.username;
 const deets = {
 var5,
 var6
 };
 res.render('index');
 dosomething(var1, var2, var3, var4, deets);
 setInterval(dosomething, 10 * 1000);
 })
 });

So what do you guys think? How would I be able to implement the passing of var1-6, through the command line? I would greatly appreciate any help from here.

I am running on Windows right now, but the target server is for Ubuntu systems.

Answer 1

In node.js you can pass CLI arguments using build in process variable

for examples

// test.js
var args = process.argv;
console.log(args[0]); // it will give the node executable path
console.log(args[1]); // it will give current file name
console.log(args[2]); // cli arguments start index

now running the code

$ node test.js hello
/usr/bin/node
/home/blackdaemon/test.js
hello

• TylerDurden: That sounds perfect! Thank you very much, I will give it a try now :D
• tbhaxor: better use process.argv.splice(2) to extract only an array of cli arguments. thanks

Answer 2

If you like a pattern like "-arg" "value" try this:

var getArgs = function(){
 var arr = {};
 var last;
 process.argv.forEach((a, idx) => {
 if(idx > 1){
 if(last){
 arr[last] = a;
 last = undefined;
 }
 else if(!last && a.match(/-\w+/))
 last = a;
 }
 })
 return arr;
}

The result should be:

$ node index no valid command -ar3 dsds -arg1 323
{ '-ar3': 'dsds', '-arg1': '323' }