SRE deep dive into Linux Page Cache # In this series of articles, I would like to talk about Linux Page Cache. I believe that the following knowledge of the theory and tools is essential and crucial for every SRE. This understanding can help both in usual and routine everyday DevOps-like tasks and i...



Interests: Regular Expressions, Linux CLI one-liners, Scripting Languages and Vim

Learn GNU sed with hundreds of examples and exercises
Hello!
I am pleased to announce a new version of my CLI text processing with GNU sed ebook. This book heavily leans on examples to present features one by one. In addition to sed commands and options, regular expressions are also discussed in detail.
Links
You can read the book online here: https://learnbyexample.github.io/learn_gnused/
Interactive TUI app for exercises: https://github.com/learnbyexample/TUI-apps/blob/main/SedExercises
Feedback
I would highly appreciate it if you'd let me know how you felt about this book. It could be anything from a simple thank you, pointing out a typo, mistakes in code snippets, which aspects of the book worked for you (or didn't!) and so on. Reader feedback is essential and especially so for self-published authors.
Happy learning :)

Linux Page Cache

Understanding Context Manager and its Syntastic Sugar

SSH Tips and Tricks
Since I joined Charm, I’ve been working and learning more about SSH, and I thought I would share a few quick tips and tricks with you. Forward Yubikey Agent If you use a Yubikey (you should), you can use it in your remotes by having the key in a SSH agent and forwarding it. To manage the agent, I st...

Things that go wrong with disk IO
Things that go wrong with disk IO

Already done grep, sed, coreutils, cli basics and more. See https://learnbyexample.github.io/learn_gnuawk/buy.html#book-list for links.

Well, if you are comfortable with Python scripts, there's not much reason to switch to awk
. Unless perhaps you are equating awk
to Python as scripting languages instead of CLI usage (like grep
, sed
, cut
, etc) as my ebook focuses on. For example, if you have space separated columns of data, awk '{print $2}'
will give you just the second column (no need to write a script when a simple one-liner will do). This of course also allows you to integrate with shell features (like globs).
As a practical example, I use awk
to filter and process particular entries from financial data (which is in csv format). Just a case of easily arriving at a solution in a single line of code (which I then save it for future use).

I wrote an ebook on GNU awk with hundreds of examples and exercises
Hello!
I am pleased to announce a new version of my CLI text processing with GNU awk ebook. This book will dive deep into field processing, show examples for filtering features, multiple file processing, how to construct solutions that depend on multiple records, how to compare records and fields between two or more files, how to identify duplicates while maintaining input order and so on. Regular expressions will also be discussed in detail.
Book links
To celebrate the new release, you can download the PDF/EPUB versions for free till 06-April-2025.
Or, you can read it online at https://learnbyexample.github.io/learn_gnuawk/
Interactive TUI apps
- 80+ exercises: https://github.com/learnbyexample/TUI-apps/blob/main/AwkExercises
- Brief tutorial: https://github.com/learnbyexample/TUI-apps/blob/main/AwkTutorial
Feedback
I would highly appreciate it if you'd **let me know how yo



Learn how to use Magit, an essential tool for any git-loving Emacs user. Magit supercharges your git workflow by removing the tedium of writing arcane commands and replacing them with a simple and ergonomic user interface.


I’ve been working on improving the startup time of Posting recently. Posting is a TUI application built with Textual, and written in Python, for managing and sending HTTP requests. This post is an overview of some of the techniques (and hacks) I used and the gains made, including: Using python -X im...

I wrote an interactive TUI app with 70+ CLI text processing exercises
Terminal User Interface (TUI) apps. Contribute to learnbyexample/TUI-apps development by creating an account on GitHub.



What `git config` settings should be defaults by now? Here are some settings that even the core developers change.


I'll recommend some from the lesser known progression fantasy genre:
- Cradle by Will Wight
- Mage Errant by John Bierce
- Mother of Learning by Nobody103 (Domagoj Kurmaić)
- The Weirkey Chronicles by Sarah Lin
- Beware of Chicken by CasualFarmer
- Super Powereds by Drew Hayes

$HOME, Not So Sweet $HOME

Home, Not So Sweet Home. GitHub Gist: instantly share code, notes, and snippets.


Table of Contents Introduction Hardware Details of caches and memory Latency, bandwidth, and throughput Latency & pointer chasing Pointer chasing Bounds checking Padding elements Raw pointers Aligned memory & Hugepages Summary Random access throughput & batching Batching Line fill buffers The reorde...

Not my site, just sharing a link I saw on HN.


Every ops team has some manual procedures that they haven’t gotten around to automating yet. Toil can never be totally eliminated. Very often, the biggest toil center for a team at a growing …


Examples and brief explanations for cryptic awk one-liners.

Dissecting various compression algorithms.

Well, I'm not going to even try understanding the various features used in that sed
command. I do know how to use basic loops with labels, but I never bothered with all the buffer manipulation stuff. I'd rather use awk/perl/python for those cases.

This might work, but I think it is best to not tinker further if you already have a working script (especially one that you understand and can modify further if needed).
undefined
perl -pe 's/\[[^]]+\]\((?!https?)[^#]*#\K[^)]+(?=\))/lc $&=~s:%20|\d\K\.(?=\d):-:gr/ge'

Hmm, OP mentioned "Only edit what’s between parentheses" - don't see anywhere that whole URL shouldn't be changed...

Here's a solution with perl
(assuming you don't want to change http/https after the start of (
instead of start of a line):
undefined
perl -pe 's/\[[^]]+\]\(\K(?!https?)[^)]+(?=\))/lc $&=~s|%20|-|gr/ge' ip.txt
e
flag allows you to use Perl code in the substitution portion.\[[^]]+\]\(\K
match square brackets and use\K
to mark the start of matching portion (text before that won't be part of$&
)(?!https?)
don't match ifhttp
orhttps
is found[^)]+(?=\))
match non)
characters and assert that)
is present after those characters$&=~s|%20|-|gr
change%20
to-
for the matching portion found, ther
flag is used to return the modified string instead of change$&
itselflc
is a function to change text to lowercase

GNU datamash (https://www.gnu.org/software/datamash/alternatives/) - handy tool for data munching. There's also https://github.com/BurntSushi/xsv

Check out my chapter on GNU grep BRE/ERE for those wanting to learn this regex flavor: https://learnbyexample.github.io/learn_gnugrep_ripgrep/breere-regular-expressions.html (there's also another chapter for PCRE)

See also https://github.com/TomWright/dasel

Memory, Sorrow, and Thorn by Tad Williams

I use Vim ;)
Python itself provides IDLE, which is good enough for beginners. https://thonny.org/ is another good one for beginners.
As mentioned by others, Jetbrains is good for many languages. https://www.kdevelop.org/ is another option.

I wish you success. I'm happy to use SimpleScreenRecorder(https://github.com/MaartenBaert/ssr).

I'm not the site author, just submitting the link.
Not sure which part you need to be logged in to view - I'm seeing links to different articles and exercises and they are all visible without logging (I checked in an incognito window).

I have a list of learning resources for CLI tools and scripting here: https://learnbyexample.github.io/curated_resources/linux_cli_scripting.html
I've also written a few TUI interactive apps to practice text processing commands like grep, sed, awk, coreutils, etc: https://github.com/learnbyexample/TUI-apps

Why do you think it is a phishing link? Gumroad is a well known platform to sell digital goods.
I mention it is free up to some date because it will go back to being a paid product after that.

I started reading progression fantasy on Royal Road earlier this year (a site for posting web serials). Here's my current follow list (excluding stories that are on hiatus):
- The Runic Artist — isekai, rune-based crafting, good mix of action and slice-of-life
- The Broken Knife — Kobold MC with a dragon companion, dark but compelling read, excellent worldbuilding
- Demon World Boba Shop — cozy isekai, nice characters
- Dual Wielding — slow burn, tale of two friends (both very talented), writing is good, action scenes get dark and intense
- Legends and Librarians — cozy romance, magical library (not litrpg/progression), plenty of cute creatures
- An Otherworldly Scholar — isekai, teacher MC, good worldbuilding, nice romance, great characters, plenty of twists, adventure and danger, especially enjoyed the slice-of-life stuff
- Archmage from Another World: Gaining Administrator Access — isekai from another fantasy world, lighthearted fun with good set of characters, no looming world-level threats so far
- Underkeeper — MC is a recent magical academy graduate, good at magic but works as underkeeper (no money/connections to join adventurer groups), got darker than I'm comfortable with, but loved the characters and the demon companion
- Immovable Mage — good worldbuilding, characters, plot twists and detailed magic system, clever use of plot events pushes MC towards OP, would suggest to read at least till the end of 2nd arc
- Level One God — likeable MC, cool magic stuff I haven't seen before, some bad moments are really dark, good writing
- Spire's Spite — criminally underrated with only 100+ followers, mostly been spire climbing so far, good magic system, dark and has some stuff I don't like but overall I've enjoyed it
- Blood Curse Academia — overall I enjoyed the combination of action, learning and mystery, but a lot of weird coincidences and stuff didn't make sense
- Mana Mirror — loved the concept of mana garden and the myriad customization options, writing and plot was easy to follow, third volume is the best so far
- The Maid Is Not Dead — writing felt like traditionally published epic fantasy with progression elements, slow burn but events are starting to escalate
- Dark Lord's Last Call — MC's soul is swapped with the dark lord, plans to open a tavern, enjoyable light-hearted read
- Orphan — I usually ignore the litrpg math but this one takes it a bit too far! characters all have flaws (though sometimes it becomes a bit too irritating), good worldbuilding and mystery
- Rules of Biomancy — 70 year old herbalist MC with a secret past comes across two isekai-ed people in danger of dying and decides to help, enjoying a lot

Not my blog, just sharing it here.
That said, I don't see that broken rectangle on Chromium.

Is it regex or sed/awk syntax (or both) that gives you trouble?
I had similar reaction and didn't even try to learn them for years - then I caught the stackoverflow craze of answering CLI questions (and learning from others).