Free knowledge blog: linux, programming, open source, databases, android, frameworks, web and computing in general
In this post I will show you how to use SQLite3 directly in the web browser using the original C library through WebAssembly and OPFS to store the database. In this way we will have original SQLite3 on the web to work in the browser with JS on the client side.
In this tutorial, we’ll explore how to effortlessly print receipts, invoices, and tickets on a thermal printer using Python. I’ll introduce you to a powerful plugin that I’ve developed, enabling seamless integration for Python-based applications.
With this plugin, you’ll gain the ability to effortlessly print tickets from Python, regardless of your preferred framework—whether it’s the terminal, Flask, Tkinter, Django, or any other Python-supported platform.
It provides extensive functionality, allowing you to print images, barcodes, text with accents, change fonts, rotate text, and much more, sending the ESC POS commands native to thermal printers.
Join me as we dive into the world of thermal printing using Python, empowering you to generate professional-quality prints effortlessly.
When printing receipts on thermal printers (ESC POS) sometimes it is needed to print images of any type, for example, to print the customer’s logo and so on.
In this post I will show you how to print any kind of images: you will be able to print local images, base64 images and internet images.
In this post I will show you how to print spanish text, text with accents or ñ letters on a thermal printer. I have been searching for this for a long time and now I want to share it.
Printing spanish text or diacritict text is necessary because sometimes the customer’s names or data contains some chars out of the ASCII range.
Today, I’m adding to the list of my free programs a software for managing restaurants. This program will allow you to register tables, payment methods, dishes (with photos), modify the currency, language, generate a printable menu, view the order, and even allow self-service for customers.
Moreover, the free restaurant system I’ve created is compatible with Android (Termux), Windows, Linux, and Raspberry Pi. In fact, it is compatible with any platform where C and Go can compile, including an internet server.
Throughout this post, I will show you all the features of this program, which is the largest one I’ve created so far, not because of its complexity but because of all the new things it offers, such as the installer, the multilingual section (with choice of locale and currency), ticket customization, logo, and dasboard.
In Svelte we can define functions that are going to be called when an event is triggered. For example, to call
holaMundo on the
click of an element we can indicate it as
Sometimes it is necessary to pass parameters to that function inside a Svelte component, but we cannot indicate it like this:
Since that will execute the function as soon as the component is loaded, and won’t wait for the click.
In this post I will show you how to pass arguments to functions in Svelte without calling them automatically.
In this article I will show you how to use native C# to open a thermal printer as a file and send it bytes or data including ESC POS commands.
Remember that I already have a plugin that allows you to print on thermal printers and exposes a consumable HTTP API from any programming language so that you can use it and not implement your own library, but if you want to see how it’s done, keep reading.
In this post I will show you how to fix an error that appears in my thermal printer plugin that says: Error en el servidor: sql: no rows in result set.
This error says that there are no rows in the database, and you may be wondering what printing has to do with a database, so that is exactly what I will discuss in this post.