Backaup as JSON file any public data available in a Firebase Database

firebase_backup.js

/*
---- In terminal ----
1. npm install [email protected]
2. node firebase_backup database_url
example: node firebase_backup https://docs-examples.firebaseio.com/
*/

var fs = require('fs');
var Firebase = require("firebase")
var ref = new Firebase(process.argv[2]);

ref.once("value", function(snapshot) {
    
    fs.writeFile("data.json", JSON.stringify(snapshot.val()), function(err) {
        if(err) {
            return console.log(err);
        } else {
            console.log("The file was saved!");
        }
        process.exit()
    }); 
  console.log("Saving Data");
}, function (errorObject) {
  console.log("The read failed: " + errorObject.code);
  process.exit()
});