I enjoy listening to audio books and sometimes I want to listen a little bit before going to sleep. Audible has a sleep timer built-in to the app, but I wanted my entire computer to shut down.

You can use the built-in shutdown command in Windows to schedule a shutdown. These examples will show how to schedule a shutdown and how to cancel a scheduled shutdown from the command-line.

If you want to write a C++ program that utilizes Sqlite3 you will need to take an extra step in the compile and link process in order to compile Sqlite3 with the C compiler (gcc), and then your C++ program with the C++ compiler (g++) If you try to compile Sqlite3 with g++ it will error.

For this example, I am using g++ and gcc to compile. I tested this in Windows 10 with MinGW64, but it should also work in Linux and Mac.

If you want to learn more about using SQLite3, check out my other tutorials:

• All SQLite tutorials of mine at https://www.devdungeon.com/tags/sqlite
• SQLite3 Tutorial or
• Ruby SQLite Tutorial
• Ruby ActiveRecord (without Rails) Tutorial
• PHP SQLite Tutorial

Recently I took a nice long 12-hour flight with United Airlines from the US to Tel Aviv, Israel. I was excited when I learned I could purchase wi-fi during the long flight. What would I do to kill the time? Probably the same things I normally waste my time on like browsing Reddit and chatting on Discord.

Well, too bad you can't do either of those because they are blocked. I thought maybe I could get around it by installing OpenVPN from the Google Play Store and connecting to one of my remote servers. Nope, you can't access the Google Play Store either. So I can't install any games or other apps, can't chat, and can't browse Reddit.

I paid almost $30 for wi-fi access and I can't access any of the primary things that I wanted to access on my Android tablet:

• Reddit
• Discord
• Google Play Store

Java has a tool named keytool that lets you do common tasks like

• Generate RSA keys and self-signed SSL certificates
• Import and export certificates
• Print certificate information
• Generate and sign certificate signing requests

It also stores everything in a secure file that has a master password in addition to specific passwords for each key it stores. You can think of it kind of like a little password protected SQLite database with your keys and certs (though there is no SQL involved).

Seeed Studio offers an Arduino-compatible Nano board, Seeeduino Nano. It is like an Arduino Nano, but with some noticeable differences:

• Seeeduino Nano currently costs $6.90 and the Arduino Nano $22.00
• Seeeduino Nano has a USB-C connector instead of Mini-USB
• Seeeduino Nano comes with a Grove connector

Otherwise, it has the same Atmega328P procesor, size, and pins. You can use Nano breakout boards like the Grove Shield for Arduino Nano.

This guide will look at the board features, how to compile and upload sketches using the Arduino CLI, and how to use the Grove system modules.

There are occassions when you want to expose a local port to the world so it can be accessed publicly on the internet.

For example, if you want to:

• Share you local development environment publicly
• Be able to receive webhooks from external services for your local development environment like Stripe webhooks
• Expose a local database to the internet via a remote server

One option is to log in to your router, typically https://192.169.1.254/ or something similar, and configure port forwarding. That will let you tell the router to take incoming traffic for a specific port and send it your local computer. This can be annoying because you have to undo the change when you are done, which is easy to forget about, and you may not have access to your router with admin privileges at all. You can also run in to port conflicts.

Another option is to use a remote host, like a VPS rented from a service like Digital Ocean to expose your port to the internet. You can do this by using SSH port forwarding (tunneling) to securely forward a port from your local computer to a port on the Digital Ocean VPS. In turn, you can expose that port on the VPS to the internet.

This example is like an exercise in setting up your own ngrok service.

Operating systems recognize a couple special file descriptor IDs:

• STDIN - 0 - Input usally coming in from keyboard.
• STDOUT - 1 - Output from the application that is meant to consumed by the user, stored in a file, or piped to another application for parsing. Typically goes to terminal.
• STDERR - 2 - Used for info, debug, and error messages to the user that are not intended to specifically be part of the application output. Typically goes to terminal.

This guide will look at how you can redirect and pipe these streams for better application development and system administration.

Electron is an amazing framework that lets you create desktop application using JavaScript, HTML, and CSS. It is essentially a web application that is self contained as a desktop application. The Electron API lets you access native system elements like the system tray icons, menus, dialogs, etc.

In this guide, we will look at how to create an Electron application with the Angular framework using TypeScript. We will cover:

• Building a project from scratch
• Packaging the desktop application for distribution
• Using live reloading for development
• Using Electron APIs for inter-process communication

In Windows, you sometimes need to modify environment variables. There are environment variables like %APPDATA% and %PROGRAMFILES% which contain useful paths, and others that contain things like your username (%USERNAME%). An important one that you may want to modify is %PATH%. In this guide we will look at how to set, check, update, and unset environment variables using the GUI and the command prompt.

Note that environment variables are case-insentive and that there are system-wide environment variables and user-specific environment variables.