Xah Programing Blog Archive 2018-11
minor updates.
- Linux: Get System Info
- Linux: Basic Shell Commands
- Linux: Text Processing: grep, cat, awk, uniq
- Linux: Sort Lines
- Linux: Walk Dir: find, xargs
- Linux: diff, Compare Files
- Linux: Show Directory Size: du
- Linux: View Directory as Tree
- Linux: Extract tar zip gzip lzip bzip2 xz rar
- Linux: wget (Download Web Page)
- Linux: rsync Tutorial
- Linux: How to Install/Remove Packages
🧡. thanks
Programing Language and Its Machine. Intro to Computer Hardware via Anecdotes
Programing Language and Its Machine
updated.
Math vs Programing, What-is vs How-to
added example about x==y==z
Google web crawler abuse
[More Google Abuse By Dr Neal Krawetz. At https://www.hackerfactor.com/blog/index.php?/archives/823-More-Google-Abuse.html ]
Microsoft Surface Book 2
i would like to have a Microsoft Surface Book 2
golang string, byte slice, rune slice
updated Golang: String
golang FindAllStringSubmatchIndex
am now like a #golang master. lol actually, spend 1 hour just to use FindAllStringSubmatchIndex tedious unintuitive nested slice of index pairs thing.
ramdomish repost:
Linux: Add Keyboard Shortcut to Switch App
Russian Keyboard Layout and Programing
Meaning of List, Array, Vector, Tuple, Slice, in Programing Languages
Meaning of Object in Computer Languages
#java #python #lisp #JavaScript #perl #Mathematica #php
Erik Naggum, Analogy vs Analysis, and lisp-1 lisp-2 Meaning-Space Erik Naggum, Analogy vs Analysis, and lisp-1 lisp-2 Meaning-Space old rant. 2001 #lisp
big endian or little endian?
little endians should dai. convince me otherwise. the reason big endian is more natural is cuz its compatible to the way we write numbers. three hundred and 1 is written 301, not 103. #linux
well, actually, there is no right answer.
this is similar to issue of notation for polynomial, or date, or first name last name.
For polynomial, x^3+x^2+x^1, the convention puts the most significant term first.
For date, there's yyyy-mm-dd, the most significant on left. But some eediatik country adhere to mm/dd/yyyy
wrote a binary, hexadecimal, converter
HTTP3 is coming. it'll be using UDP instead of TCP. Currently named QUIC QUIC
See also: TCP/IP Tutorial for Beginner TCP/IP Tutorial for Beginner
aspect ratio, a curious design problem
the aspect ratio, is truly a curious design problem. and problem in implementation too. if you read Wikipedia on aspect ratio, there's a lot to say
a deep dive into camelCase vs snake_case
creative domain names
in this 2010 article Intro to Video Codecs lots links are ded. One of them is .cx note that coder fashion idts who get creative with domain name. .cx is the earlist e.g. goatse.cx, then deli.cio.us then .io by google itself
2000 is the decade where things unknown to humanity are being seen. 'was, also the rise of 4chan, wikipedia, and caused the downfall of christianity, and rise of rainbow gay power with legality. Due to the uncensored n uncensorable internet. Unbeknownst to us all, this turned around into sensorship
self-reference problem in programing
one thing i noticed in past 10 years coding is the self-reference problem. e.g. suppose u design lang string delimiter. say, python
"""triple quote"""
. That's safe enough right? until, you start to process python source code itself.
See also: Programing Language Design: String Syntax
similar problem is, when you use regex to match a regex string. The escape become a problem that is basically unsolvable. i think it's still mathematically possible in general, but practically not. e.g. emacs in cygwin trying to pass regex on file path regex to Windows's .exe
other problems are, html entities encode/decode, and url % encoding/decoding, and especially together e.g. ampersand in url. HTML ampersand is especially nasty. It has the property that it's mathematically impossible to tell if a string is in decoded/encoded state.
it's mathematically impossible to tell if a string is in html ampersand decoded/encoded state, when, your string is html text that discuss ampersand encoding/decoding, e.g. a tutorial of it. You need general AI or human, to tell.
recommend a svg book?
give my tutorial a try? Practical SVG Tutorial
it's condensed version of svg 1.1 spec covering the practical parts.
otherwise, i recommend https://twitter.com/AmeliasBrain 's books
SVG Essentials: Producing Scalable Vector Graphics with XML 2nd Edition, 2014, by J. David Eisenberg, Amelia Bellamy-Royds Buy at amazon
Using SVG with CSS3 and HTML5: Vector Graphics for Web Design 1st Edition, 2017, by Amelia Bellamy-Royds , Kurt Cagle, Dudley Storey Buy at amazon
she's also the author of svg 2 spec. Svg 2 isn't much adopted afaik.
web dev work
lots work in past 2 weeks on CSS HTML. The tutorial is for quick start. It covers practical cases, concise explanation (without assuming you dummy), from my experience with html since 1995. No jargons, current design fads and jargon words. Xah Web Dev Blog
am wasting my life away
am wasting my life away. must remember, my long term goal, at this end stage of my life, say next 5 years or 10 if am lucky, is to achieve postdoc level of a geometry, and to understand proof systems, n write a compiler of my own lang. Near term goal is to complete js plot lib.
the way am currently running, is that anytime i'd depart this earth. and i don't actually have a plan. but but but btw, that's a painful thing to think about, but it's a matter of philosophy.
what's digital network audio amplifier?
there is a thing called digital network audio amplifier
i thought it's amplifying digital signals, but that doesn't make sense? it seems to do wireless audio, example: wireless speakers. How does that work? What protocol is that?
ideal syntax
lol. the last one is the most idiotic. it's spread by OOP fad since 1995, by the likes of java python ruby JavaScript
to understand the details of these syntaxs, see
Python is Pretentious
dug this up in my file ball. not sure i published it before. Python is Pretentious reading good!
Unicode: Flags 🏁
given 250 country names, can you organize them by neighbors? i just did.
interesting that most country names in Africa ends in “a”.
most eastern euro country names also ends in “a”.
while doing the Unicode Flags page i get 250 countries and need to identify them. it's a wonder, you goto online map, and dip into street view. and see places of human animals.
Grouping Europe into Regions
i was trying to group flags into regions, unassuming, then, someone from Austria saw what i did, OMG what have you done! loool :D which country is central/eastern euro, it's complicated, really complicated.
just finished properly grouping european countries.
now, if somebodies complains about the order used, we need to declare war.
red/yellow kiwi, seed of kiwi is pungent
the seed of kiwi, has a sorta pungent taste. you can taste it when it's blended into liquid. and, amazing, amazon sell fresh fruit now Buy at amazon
searching for kiwi seed, maybe chemical or other interesting read, you find red kiwi and yellow kiwi and kiwi seed oil kiwi seed
Chinese Chess
象棋，我脑🧠下不过电脑💻气死人😡 am pretty good with Chinese Chess since teens. but i can't beat computer program today.
just deleted my local copy of python 2 and python 3 docs on my site
i so despise python. and its doc is the worst among languages. see Why Python Doc Sucks
Donald Knuth, Steve Jobs, and the Idiocy of Typography (on its own page)
Steve Job says, computer is bike for the minds?
a friend gave me his used bike. that's far better than $100 at walmart. but now, getting a bike lock, will cost $50. Any advice on bike lock? am looking at this
Kryptolok 2 Mini-7 Bike Lock Buy at amazon
~2015 i saw a video where young Steve Jobs talked about how human on bicycle is more distance/energy efficient than any animal. eagle or otherwise.
here's the vid https://www.youtube.com/watch?v=KmuP8gsgWb8
here's earlier diff one https://www.youtube.com/watch?v=ob_GX50Za6c (1.5 minutes)
i took a walk for 30 min and monologued about it. Note, bicycle itself won't do. You need paved roads. When you consider paved roads, the energy and effort required, bike then isn't exactly efficient, at all.
once you take paved road into account, then, there's the technology required for paved road. Also, all the precision machinery required for building a bicycle, e.g. gears, rubber on wheels, wire of breaks. that's really effort of thousands years of humanity.
then, the inspiration of “computer is bicycle for the minds” becomes silly. Note, the impetus of video tech are much due 2 pn. Much of Apple's success lies in human vanity. AI is driven by $ and military. $ and power, drives mankind.
The Python Unicode Mess
good articles.
[The Python Unicode Mess By John Goerzen. At https://changelog.complete.org/archives/9938-the-python-unicode-mess ]
and for in depth detail about this, see
[Practical Python porting for systems programmers, version 1.9 By Peter A Donis And Eric S Raymond. At http://www.catb.org/esr/faqs/practical-python-porting/ ]
See also: Python: Unicode Tutorial 🐍
paper ipad screen cover
there is such a thing. “paper screen cover” for ipad. Buy at amazon So that, when you use a pen to draw, it has friction like on paper, instead of gliding on glass.
𓋇
google web font refuse to show in @brave browser
google font https://fonts.google.com/ refuse to show if you are using @brave browser
i never actually use google font. i stick to Arial. I think we should just have 3 basics. serif, sans, mono. Font should be ban'd. and fakwestern alphabetical ignoramus tech geekers. i knew am gonna get lots drivels about this from the hacker types
http://rezich.com/ roboto is nice. it's logical and geometrical and simple, as most google's designs tends to be inhuman. i was thinking of using it few years back but decided don't want to have user download it. and these days, i wouldn't use anything google.
Apple not supporting SVG
it's interesting that Apple is not actively supporting SVG. e.g. there is no default viewer.
See also: Practical SVG Tutorial