防衛省サイバーコンテスト 2025 writeup - st98 の日記帳 - コピー
2/2に12時間というちょうどよい競技時間で開催された。21時終了だったけれども、11時45分ぐらいに最速で全完して1位🎉 第1回以来4年ぶりの優勝だ。昨年大会の第4回ではヒントの閲覧数で優勝を逃してしまって悔しい思いをしたので、雪辱を果たすことができ嬉しい。開始直後からずっと1位を独走できており、450名以上のプレイヤーがいる中で圧勝だったのも嬉しい。 昨年度や一昨年度はバルクが作問を担当していたが、今回はAGESTが担当していた。これまでの問題と比較すると全体的に易化したように思うが、解くにあたって発想の大きな飛躍を必要とするいわゆる「エスパー要素」のある問題はごく一部を除いて存在しておらず*1、よかったと思う。また、昨年度・一昨年度に引き続きwriteupは公開可能というのもよかった。 戦略というほどの戦略は立てていなかったけれども、とりあえずWebを見た後は全カテゴリを上から見て
Developers are increasingly relying on AI coding assistants to accelerate our daily workflows. These tools can autocomplete functions, suggest bug fixes, and even generate entire modules or MVPs. Yet, as many of us have learned, the quality of the AI’s output depends largely on the quality of the prompt you provide. In other words, prompt engineering has become an essential skill. A poorly phrased
A few months ago, I set myself the challenge of writing a C compiler in 500 lines of Python1, after writing my SDF donut post. How hard could it be? The answer was, pretty hard, even when dropping quite a few features. But it was also pretty interesting, and the result is surprisingly functional and not too hard to understand! There's too much code for me to comprehensively cover in a single blog
LogLog Games
The article is also available in Chinese. Disclaimer: This post is a very long collection of thoughts and problems I've had over the years, and also addresses some of the arguments I've been repeatedly told. This post expresses my opinion the has been formed over using Rust for gamedev for many thousands of hours over many years, and multiple finished games. This isn't meant to brag or indicate su
TL;DR; We are changing std::sort in LLVM’s libcxx. That’s a long story of what it took us to get there and all possible consequences, bugs you might encounter with examples from open source. We provide some benchmarks, perspective, why we did this in the first place and what it cost us with exciting ideas from Hyrum’s Law to reinforcement learning. All changes went into open source and thus I can
Weird Lexical Syntax
I just learned 42 programming languages this month to build a new syntax highlighter for llamafile. I feel like I'm up to my eyeballs in programming languages right now. Now that it's halloween, I thought I'd share some of the spookiest most surprising syntax I've seen. The languages I decided to support are Ada, Assembly, BASIC, C, C#, C++, COBOL, CSS, D, FORTH, FORTRAN, Go, Haskell, HTML, Java,
Golang Mini Reference 2022: A Quick Guide to the Modern Go Programming Language (REVIEW COPY)
Golang Mini Reference 2022 A Quick Guide to the Modern Go Programming Language (REVIEW COPY) Harry Yoon Version 0.9.0, 2022-08-24 REVIEW COPY This is review copy, not to be shared or distributed to others. Please forward any feedback or comments to the author. • feedback@codingbookspress.com The book is tentatively scheduled to be published on September 14th, 2022. We hope that when the release da
Parsing SQL - Strumenta
The code for this tutorial is on GitHub: parsing-sql SQL is a language to handle data in a relational database. If you worked with data you have probably worked with SQL. In this article we will talk about parsing SQL. It is in the same league of HTML: maybe you never learned it formally but you kind of know how to use it. That is great because if you know SQL, you know how to handle data. However
Update 1.80.1: The update addresses these issues. Update 1.80.2: The update addresses this security issue. Downloads: Windows: x64 Arm64 | Mac: Universal Intel silicon | Linux: deb rpm tarball Arm snap Welcome to the June 2023 release of Visual Studio Code. There are many updates in this version that we hope you'll like, some of the key highlights include: Accessibility improvements - Accessible V
Join a VS Code Dev Days event near you to learn about AI-assisted development in VS Code. Update 1.54.1: The update addresses an issue with an extension dependency. Update 1.54.2: The update addresses these issues. Update 1.54.3: The update addresses this issue. Downloads: Windows: x64 Arm64 | Mac: Universal Intel silicon | Linux: deb rpm tarball Arm snap Welcome to the February 2021 release of Vi
Patterns for Building LLM-based Systems & Products [ llm engineering production 🔥 ] · 66 min read Discussions on HackerNews, Twitter, and LinkedIn “There is a large class of problems that are easy to imagine and build demos for, but extremely hard to make products out of. For example, self-driving: It’s easy to demo a car self-driving around a block, but making it into a product takes a decade.”
Join a VS Code Dev Days event near you to learn about AI-assisted development in VS Code. Update 1.70.1: The update addresses these issues. Update 1.70.2: The update addresses these issues. Update 1.70.3: This update is only available for Windows 7 users and is the last release supporting Windows 7. Downloads: Windows: x64 Arm64 | Mac: Universal Intel silicon | Linux: deb rpm tarball Arm snap Welc
A Walk with LuaJIT
The following is a chronicle of implementing a general purpose zero-instrumentation BPF based profiler for LuaJIT. Some assumptions are made about what this entails and it may be helpful to read some of our other work in this area. One major change from prior efforts is that instead of working with the original Parca unwinder we are now working with the OpenTelemetry eBPF profiler. If you missed t
python_modules.pdf
Python3 OpenCV / Pillow / pygame / Eel / PyDub / NumPy / matplotlib / SciPy / SymPy / gmpy2 / hashlib, passlib / Cython / Numba / ctypes / PyInstaller / curses / tqdm / JupyterLab / json / psutil / urllib / zenhan / jaconv Copyright © 2017-2025, Katsunori Nakamura 2025 8 19 Python ‘ .py’ Python Python Windows PSF Python py .py Enter macOS Linux PSF Python python3 .py Enter Anaconda Prompt Python p
Tier 4 Support § Support for these targets is entirely experimental. If this target is provided by LLVM, LLVM may have the target as an experimental target, which means that you need to use Zig-provided binaries for the target to be available, or build LLVM from source with special configure flags. zig targets will display the target if it is available. This target may be considered deprecated by
Real-world gen AI use cases from the world's leading organizations | Google Cloud Blog
AI is here, AI is everywhere: Top companies, governments, researchers, and startups are already enhancing their work with Google's AI solutions. Published April 12, 2024; last updated October 9, 2025. A year and a half ago, during Google Cloud Next 24, we published this list for the first time. It numbered 101 entries. It felt like a lot at the time, and served as a showcase of how much momentum b
It is December. That means annoying Christmas things are everywhere, including but not limited to the annual programming semi-competition known as Advent of Code. The problem with Advent of Code is that it is a waste of time. Most of the puzzles are in the realm of either string processing (somewhat applicable to programming), logic puzzles (not really applicable to most programming), or stupid go
How a simple Linux kernel memory corruption bug can lead to complete system compromise
In this case, reallocating the object as one of those three types didn't seem to me like a nice way forward (although it should be possible to exploit this somehow with some effort, e.g. by using count.counter to corrupt the buf field of seq_file). Also, some systems might be using the slab_nomerge kernel command line flag, which disables this merging behavior. Another approach that I didn't look
Speed of Rust vs C
The run-time speed and memory usage of programs written in Rust should about the same as of programs written in C, but overall programming style of these languages is different enough that it's hard to generalize their speed. This is a summary of where they're the same, where C is faster, and where Rust is faster. Disclaimer: It's not meant to be an objective benchmark uncovering indisputable trut
I want to write a post about Pitchfork, explaining where it comes from, why it is like it is, and how I see its future. But before I can get to that, I think I need to share my mental model on a few things, in this case, Ruby’s GVL. For quite a long time, it has been said that Rails applications are mostly IO-bound, hence Ruby’s GVL isn’t that big of a deal and that has influenced the design of so
Tier 4 Support § Support for these targets is entirely experimental. If this target is provided by LLVM, LLVM may have the target as an experimental target, which means that you need to use Zig-provided binaries for the target to be available, or build LLVM from source with special configure flags. zig targets will display the target if it is available. This target may be considered deprecated by
Python behind the scenes #13: the GIL and its effects on Python multithreading
As you probably know, the GIL stands for the Global Interpreter Lock, and its job is to make the CPython interpreter thread-safe. The GIL allows only one OS thread to execute Python bytecode at any given time, and the consequence of this is that it's not possible to speed up CPU-intensive Python code by distributing the work among multiple threads. This is, however, not the only negative effect of
State of the Common Lisp ecosystem, 2020 🎉 - Lisp journey
NEW: 9 videos (86min) about CLOS on my Common Lisp course. Out of 7h+ of content. Rated 4.7/5. Learn more and stay tuned. 🎥 I also have cool Lisp showcases on Youtube . The last ones: how to build a web app in Common Lisp, part 1 and 2. This is a description of the Common Lisp ecosystem, as of January, 2021, from the perspective of a user and contributor. The purpose of this article is both to gi
Fantastic Learning Resources Aug 6, 2023 People sometimes ask me: “Alex, how do I learn X?”. This article is a compilation of advice I usually give. This is “things that worked for me” rather than “the most awesome things on earth”. I do consider every item on the list to be fantastic though, and I am forever grateful to people putting these resources together. Learning to Code I don’t think I hav
prompts.chat
Welcome to the “Awesome ChatGPT Prompts” repository! While this collection was originally created for ChatGPT, these prompts work great with other AI models like Claude, Gemini, Hugging Face Chat, Llama, Mistral, and more. ChatGPT is a web interface created by OpenAI that provides access to their GPT (Generative Pre-trained Transformer) language models. The underlying models, like GPT-4o and GPT-o
Rewriting Rust
The Rust programming language feels like a first generation product. You know what I mean. Like the first iPhone - which was amazing by the way. They made an entire operating system around multitouch. A smart phone with no keyboard. And a working web browser. Within a few months, we all realised what the iPhone really wanted to be. Only, the first generation iphone wasn't quite there. It didn't ha
Update 1.75.1: The update addresses these issues. Downloads: Windows: x64 Arm64 | Mac: Universal Intel silicon | Linux: deb rpm tarball Arm snap Welcome to the January 2023 release of Visual Studio Code. There are many updates in this version that we hope you'll like, some of the key highlights include: Profiles - Create and share profiles to configure extensions, settings, shortcuts, and more. VS
Sometimes debuggers and profilers are obviously broken, sometimes it's subtle and hard to spot. From my flame graphs page: (Click for original SVG.) This is pretty common and usually goes unnoticed as the flame graph looks ok at first glance. But there are 15% of samples on the left, above "[unknown]", that are in the wrong place and missing frames. The problem is that this system has a default li
Infinite Mac: An Instant-Booting Quadra in Your Browser
tl;dr I’ve extended James Friend’s in-browser Basilisk II port to create a full-featured classic 68K Mac in your browser. You can see it in action at system7.app or macos8.app. For a taste, see also this screencast: Backstory It’s a golden age of emulation. Between increasing CPU power, WebAssembly, and retrocomputing being so popular The New York Times is covering it, it’s never been easier to re
Try Mastering Emacs for free! Are you struggling with the basics? Have you mastered movement and editing yet? When you have read Mastering Emacs you will understand Emacs. It’s that time again: there’s a new major version of Emacs and, with it, a treasure trove of new features and changes. Notable features include the formal inclusion of native compilation, a technique that will greatly speed up y
Amazon FSx for NetApp ONTAPファイルシステム上のiSCSI LUNをマウントしてみた | DevelopersIO
Amazon FSx for NetApp ONTAPは単純なファイルサーバーじゃないぞ こんにちは、のんピ(@non____97)です。 皆さんはMulti-AZのEBSボリュームを欲しいなと思ったことはありますか? 私はあります。 EBSボリュームはAZ単位なのでAZ障害のことを考えるとちょっと心配です。かと言って自分でブロックレベルのレプリケーションを実装するのも何だか大変です。 そこで、Amazon FSx for NetApp ONTAPの出番です。 Amazon FSx for NetApp ONTAPはファイルサーバーとしての機能だけではなく、ブロックストレージとしての機能も有しています。 Q: Amazon FSx for NetApp ONTAP はどのプロトコルをサポートしていますか? A: Amazon FSx for NetApp ONTAP は、ネットワークファイ
Reflection is something a lot of people wish the Rust language had: It is not hard to stumble across somebody with an interesting use case for it. People want to use it for serialization, GCs, better interop, and so, so much more. If you can think of a task, there is somebody out there wishing they could implement it using reflection. Sadly, it does not look like it is coming any time soon. Still,
Improved portability and performance 🦀 libimagequant is a library for generating high-quality palettes, useful for compression of transparent PNG images (~75% smaller!) and making nice GIF animations. libimagequant is now a pure Rust library. The new version is a drop-in replacement (ABI-compatible), so C projects can continue using it. The C version will be maintained for a while to give library
Plan 9 Desktop Guide
PLAN 9 DESKTOP GUIDE INDEX What is Plan 9? Limitations and Workarounds Connecting to Other Systems VNC RDP SSH 9P Other methods Porting Applications Emulating other Operating Systems Virtualizing other Operating Systems Basics Window Management Copy Pasting Essential Programs Manipulating Text in the Terminal Acme - The Do It All Application Multiple Workspaces Tiling Windows Plumbing System Admin
An AI-native software engineer is one who deeply integrates AI into their daily workflow, treating it as a partner to amplify their abilities. This requires a fundamental mindset shift. Instead of thinking “AI might replace me” an AI-native engineer asks for every task: “Could AI help me do this faster, better, or differently?”. The mindset is optimistic and proactive - you see AI as a multiplier
While getting my degree in Physics, I had to take classes in both MatLab and Python for scientific computing. I preferred python, where we used the SciPy and NumPy packages. In fact, I used those packages again (along with matplotlib) in an undergraduate research project simulating bacteria films. There's a catch: I was also pursuing a degree in Computer Science, and Python just wasn't fast enough
Following up from the last post, there is a lot more we need to cover. This was intended to be the post where we talk exclusively about benchmarks and numbers. But, I have unfortunately been perfectly taunted and status-locked, like a monster whose “aggro” was pulled by a tank. The reason, of course, is due to a few folks taking issue with my outright dismissal of the C and C++ APIs (and not showi
The Pitchfork Story
A bit more than two years ago, as part of my work in Shopify’s Ruby and Rails Infrastructure team, I released a new Ruby HTTP server called Pitchfork. It has a bit of an unusual design and makes hard tradeoffs, so I’d like to explain the thought process behind these decisions and how I see the future of that project. Unicorn’s Design Is Fine Ever since I joined Shopify over 11 years ago, the main
Over the past decade, my work has centred on partnering with teams to build ambitious products for the web across both desktop and mobile. This has provided a ring-side seat to a sweeping variety of teams, products, and technology stacks across more than 100 engagements. While I'd like to be spending most of this time working through improvements to web APIs, the majority of time spent with partne
Flipping Pages: An analysis of a new Linux vulnerability in nf_tables and hardened exploitation techniques
This blogpost is the next instalment of my series of hands-on no-boilerplate vulnerability research blogposts, intended for time-travellers in the future who want to do Linux kernel vulnerability research. Specifically, I hope beginners will learn from my VR workflow and the seasoned researchers will learn from my techniques. In this blogpost, I'm discussing a bug I found in nf_tables in the Linux
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The Prompt Engineering Playbook for Programmers
Writing a C compiler in 500 lines of Python
Changing std::sort at Google’s Scale and Beyond
June 2023 (version 1.80)
February 2021 (version 1.54)
Patterns for Building LLM-based Systems & Products
July 2022 (version 1.70)
0.8.0 Release Notes ⚡ The Zig Programming Language
Advent of Code on the Nintendo DS
So You Want To Remove The GVL?
0.10.0 Release Notes ⚡ The Zig Programming Language
Fantastic Learning Resources
January 2023 (version 1.75)
The Return of the Frame Pointers
What's New in Emacs 28.1?
Rust, reflection and access rules
Rust is more portable than C for pngquant/libimagequant
The AI-Native Software Engineer
Scientific Computing in Rust - aftix's dominion
cuneicode, and the Future of Text in C
If Not React, Then What? - Infrequently Noted