How to see running processes in Linux

One essential command to know when you are experimenting in Linux is the command to see which processes are running in your machine, just in case you need to kill one of them for any reason. This command is top and you use it like this: Type top in a Linux Terminal and press Enter: pi@raspberrypi:~ $ top You should …

How to know which Linux version you are running

Easy peasy! Run the following command in a Terminal: lsb_release -a You should see something similar to this: pi@raspberrypi:~ $ lsb_release -a No LSB modules are available. Distributor ID: Raspbian Description: Raspbian GNU/Linux 10 (buster) Release: 10 Codename: buster

How to reset Raspbian 10 (Buster) password on Raspberry PI 4

Hey! if you are reading this chances are you forgot the password to your Raspberry PI. Worry not though here is how to reset it on Raspbian 10 Buster using a Raspberry PI 4, I don’t really think the model of Raspberry PI matters but it’s just to give you a better idea of my environment. First start your Raspberry …

How to delete a collection of IDs in POSTMAN

Today I had to delete several objects that I created when testing an API. It was very easy to click the Send button and create a bunch of stuff but now I have to clean the DB. I am using Postman as testing tool and I chose to execute the following code in the Pre-request Script of my test. The …

How to delete a WordPress.com website

If you are like me and you have a new hosting service for your blogs you may know that after moving from WordPress.com to WordPress.org you may want to delete that old website. Here is how to do it. 1- Open your web browser and navigate to the blog you want to delete, in my case https://kryptosit.wordpress.com 2- Click on …

Base64 URL Safe Encoding / Decoding (RFC-7515)

A few days back I was required to encode some string in base 64 URL safe. After some research I found that there are several variants of base 64. The one implemented in the code below corresponds to RFC-7515. Here is the code: function encodeBase64Url(str) { let s = new Buffer(str).toString(‘base64’); // Regular base64 encoder s = s.replace(‘=’, ”); // …

How to remove documents from a capped collection in MongoDB

You can’t remove one or all documents from a capped collection in MongoDB. BUT! you can drop the collection! Execute the following command: db.getCollection(‘myCollection’).drop() The result for me is: true There you go, quick and easy. Sources https://docs.mongodb.com/manual/core/capped-collections/ https://stackoverflow.com/questions/33048282/how-to-remove-a-document-from-the-capped-collection

How to count documents of a collection in MongoDB

Today, I had to do this at work. turns out it is very easy. I am using Robomongo 1.0-RC1. I just double click on the collection that I want, in this case knives and I just execute the following query: db.getCollection(‘knives’).count() The result in my case is: 1911 Hope it helps! Sources https://docs.mongodb.com/manual/reference/method/db.collection.count/

How to create a strong password?

There are a few things you can do to create a strong password that will protect your account from being compromised. Use lower case, upper case, numbers, and symbols (check list of valid symbols, this could vary depending on the website / system) Use at least 12 chars to allow a wide key space Don’t use common words or easy-to-guess …

How to generate random bytes in Node.JS

Easy! I discovered this recently and it is interesting to me. Here is a quick example: const crypto = require(‘crypto’); console.log(crypto.randomBytes(1).toString(“hex”)); console.log(crypto.randomBytes(2).toString(“hex”)); console.log(crypto.randomBytes(4).toString(“hex”)); console.log(crypto.randomBytes(8).toString(“hex”)); console.log(crypto.randomBytes(16).toString(“hex”)); console.log(crypto.randomBytes(32).toString(“hex”)); console.log(crypto.randomBytes(64).toString(“hex”)); When you run this code you might see something similar to this: E:\NodeJS>node randomCrypto.js d8 dccd 0709fee2 67d6d7c51cc59f0d af19069e601e47a9141d27d7d828a9d0 f83b7547452099462061734791da57443cc60828de7dcb8f7494eedceb3c889c e2e4a1faaf4190898aaf4fa786e20fe076237854ae4628127cb2eda4bafd3000b42788e347ade94d0c98614a40586b71ded3044879f791adedd6c0d4bb22e9ac The argument passed to the function is the length in bytes, when …