Introduction If you’re familiar with command-line interfaces, you might have seen flags like -h, -v, --name foo, etc. Some of the flags use primitive data types like string, int, bool, etc. The rest of the flags are custom flags that using specific patterns or data structure like IP, URL, Array, Map…

Introduction Many of you might have heard of the database credential rotation. It is a common solution for securing your database. Many providers have implemented this solution such as Hashicorp Vault, AWS Secret Manager, etc. By automatically rotating your database credential, no one can really know how to connect to the…

Introduction I revisit some of my college notes, and find that in my first year of college, in Algorithm and Programming Course, the Bitwise operator was mentioned but wasn’t highlighted. It’s either I didn’t write the notes on that specific topic (I stopped writing notes in my second semester) or the…

Introduction When it comes to maintaining a large application codebase, sometimes you are confused with dependencies. Moreover, when you create a new struct that depends on a struct with many attributes, you need to provide those attributes manually. What if those attributes need other structs? It will take forever. Dependency injection…

Syntax [cmd] <<[-] delimeter [cmd] contents delimeter All contents will be passed to the cmd as an input, examples below will use EOF as a delimeter and cat as a command, you can change to whatever you want. With Variable cat <<EOF echo "$HOME" EOF result: echo "/home/clavinjune" Escape Variable Use \$ instead of $…

Introduction Sometimes, when you need to modify a file that needs root permission, you forgot to use sudo before open it using vim. This is quite annoying when you have changed a lot of lines, but you can’t save the modification. Even though Vim has already warned us before editing using…

To use a random available port in Golang, you can use :0. I believe the port 0 would works for another language as well as I tried in python. $ python -m SimpleHTTPServer 0 Serving HTTP on 0.0.0.0 port 43481 ... According to lifewire, port 0 is a non-ephemeral port…

Introduction As embed package released on Golang v1.16, now you can include any of your files into your golang binary. You can also serve the embedded file as a static site. But when it comes to subdirectories, you need to handle it a bit differently. In this article, you will learn…

Introduction As a software engineer, you need to learn every day to keep your knowledge up-to-date. Any improvement in any aspect would help you write a better code. After writing more and more Golang code, I realized that I could improve this blog post. As you see in that post, you…