Sekai ๐ŸŒ ๐Ÿ—บ

Sekai (ไธ–็•Œ) is the kanji for “the world”. That’s a great word because of the scale that it designates.

Finding Pandoc Logo

Background

I’m writing my guide for preparing simple documents. I hope that users can prepare documents efficiently and the prepared documents look smart.

Problem

To help readers get my message in the linked guide, I used many icons from Font Awesome. However, it doesn’t include pandoc’s logo. I tried searching that using the search string “pandoc logo filetype:svg”. Duckduckgo couldn’t find any results. Luckily, Google found many SVGs. The first result linked to a relevant discussion on Google Groups. However, all posts were collapsed, and the desired SVG didn’t show up.

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pandoc  SVG 

Some Public APIs to Be Viewed

API description
JSON Placeholder mock REST APIs for development only
Google Translate generate free translations up to a certain limit
Open Weather Map weather prediction across the world
REST Countries info about the world’s countries
IP API data about IP addresses
Random Data API like the first one, but with a sharper focus on random data
Pokemon API info about Pokemon with recent introduction of GraphQL API

Merge Two PDF to Single Encrypted PDF

Problem

I have unprotected

  1. input1.pdf
  2. input2.pdf

and I want to create one single encrypted.pdf.

My try

I looked up QPDF’s manual and tried the following command.

qpdf --empty --pages input{1,2}.pdf --encrypt upw opw 256 -- encrypted.pdf

but I got this error.

qpdf: unrecognized argument --encrypt (pages options must be terminated with --)

For help:
  qpdf --help=usage       usage information
  qpdf --help=topic       help on a topic
  qpdf --help=--option    help on an option
  qpdf --help             general help and a topic list

Solution

The sentence inside the parentheses says it all.

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PDF  QPDF 

How to Start an Online Empire Without a Job

A quick way to begin your online empire

Difficulty

To start an online empire from zero is not something that can be done easily. One lacks the connection with experienced netizens who might know the inside secrets.

Solution

You may start your empire on Forge of Empires. You’ll be guided by a beginner-friendly tutorial. The daily tasks are easy and they will only take you a few minutes, but they are rewarding. You’ll end up earning thousands of coins on the website.

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FoE 

Ten Probably Handy Sites

A brief summary of 10 Incredibly Useful Websites on Medium.

Upword.AI (paid)
summarise stuff
Gamma (free trial for the moment)
get professional slides in min, not open source
IMGCreator (free, point-based)
text/img โ†’ img, chatGPT powered
Popsy (free to create, paid to publish)
no-code website buider
Visual Capitalist (free)
explanatory charts
TypeLit.io (free for some ล“uvres, paid for own book)
type classics out to train typing
Zorp.one (free for trial, paid for deploy)
no-code app generator for businesses, e.g. delivery, store management, doc collection
Kialo (free)
repository for debate arguments, with discussion topology
Nomad List (free limited trial, paid content)
good for remote workers, find remote work opportunities, insights into cities, dating app (that I don’t recommend)
SuperMeme (paid)
AI meme generator

Encrypt PDF on Command Line

Background

On M$ Win*, I don’t have dedicated PDF readers like Adobe.

During visioconference, one might want to share some downloaded PDFs. Those documents can be part of an ebook or notes. In some situations, they can provide context to a discussion.

Problem

  1. Under the same folder, you might have
  • downloaded_ebook.pdf
  • personal_info.pdf
  • other_personal_stuff.pdf that you don’t want to expose while streaming.

However, each downloaded PDF usually comes with a name set by others. It can be tedious to rename them according to your own habits. To protect users’ privacy, we can

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PDF  QPDF 

Adjust Git Bash Font and Window Size

Goal

Make the characters larger and more readable.

Solution

The option names might be found in the manual. Sometimes, I find opening MINGW’s settings through GUI helpful.

FontHeight=12
Columns=143
Rows=36

I’ve read Gerald Lee’s .minttyrc. I’ve enlarged the window size so that in the standard output, one line can contain more info.

Fujitsu LH532 Thermal Paste Application

Background

My old laptop was bought ten years ago. I had never changed the thermal paste between its CPU and its fan. As a result, it had been getting hot during my online tutorials.

Photos

thermal paste on CPU

thermal paste on CPU displaced after ten years

thermal paste on fan

thermal paste on fan displaced after ten years

CPU and fan cleaned

dried thermal paste cleaned and removed

with isopropyl and kitchen towel

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Removed jQuery Dependency from My Math Editor

Background

jQuery provides many handy functions to speed up the development, for example document.ready(), element.toggle(), element.hide(), etc. My math editor used some of them. However, I replaced them with Vanilla JavaScript at commit 4a35c45b.

Goal

Some users complained about the white background in the past versions of my editor. That had motivated me to refactor the code, so that it would be easier to maintain and to add in new features.

HTML5 input types used

Actual appearance might vary across browsers.

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Showdown KaTeX With mhchem

mhchem support for Showdown-KaTeX

Background

I’ve written about bringing user-defined KaTeX macros into Hugo a few years ago. Looking back, I realized that I only knew how to copy code at that time.

Goal

  1. To replace the current code for my math editor with Showdown-KaTeX.
  2. To bring mhchem into my LaTeX + Markdown sandbox.

Motivation

To get the benefits of the three free (as in “freedom”) technologies.

  1. Markdown syntax is (much) simple(r than its LaTeX equivalent, especially for tables, ordered/unordered lists, etc).
  2. LaTeX syntax for math is, in the long run, worth learning, so that your fingers can stay on the keyboard while editing math expressions.
  3. mhchem allows writing chemical equations conveniently as in the previous point.

However, Rattle has pointed out the difficulties of mixing LaTeX and Markdown syntax. In his proposed solution for WordPress, he first renders KaTeX before moving to Markdown. He has provided an example use case with a dollar sign $ in a normal Markdown content (e.g. An apple costs $1.5.)

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