何を言っているんだと思われるかもしれないですが、気軽にパスワードの1文字目に「~」を使わないほうがいいというお話です。 起こった問題 踏み台サーバー経由でサーバーAに接続して作業をしていた時の話です。 いわゆる多段 ssh 接続というもので、リモートワークになってからは結構使われる方も多いかと思います。 サーバーA上で root 権限になろうと sudo su - してパスワードを入力したら Connection to xxx.xxx.yyy.zzz closed. の文字とともにサーバーAから追い出されてしまいました。 なにかの間違いだろうと何度か挑戦していたのですが、結果はサーバーAから切断され踏み台サーバーに戻る羽目に。。。 そのときに入力していたパスワードが ~.xxxxxxxxxx のような ~ から始まるものでした。 調査 ~ って何か意味があったよなーと思ってどう調べようかと
0 issue "letsencrypt.org" 0 issuewild "letsencrypt.org" 0 iodef "mailto:yourmail@example.jp" §OS再インストール 初期設定で期待通りの設定ができていない場合は、OSの再インストールをする。 さくらVPSのコントロールパネルから、OSを再インストールするサーバを選ぶ。 www99999ui.vs.sakura.ne.jp §OSのインストール操作 Ubuntu 24.04 LTS を選ぶ。 OSインストール時のパケットフィルタ（ポート制限）を無効にして、ファイアウォールは手動で設定することにする。 初期ユーザのパスワードに使える文字が制限されているので、ここでは簡単なパスワードにしておき、後ですぐに複雑なパスワードに変更する。 公開鍵認証できるように公開鍵を登録しておく。 §秘密鍵と公開鍵の作成 ク
Go プログラミング言語仕様
Go プログラミング言語仕様 本文書は，The Go Programming Language Specification version 2021/02/10 のなんちゃって日本語訳である． 原文ソース：https://github.com/golang/go/blob/master/doc/go_spec.html 訳文ソース：https://github.com/hiwane/gospec-ja．誤訳・誤字脱字などは issue かプルリクで https://hiwane.github.io/gospec-ja/ 訳注 valid/invalid は有効/無効, legal/illegal は正当/不当と訳す． letter と character を区別するため，letter は英字，character は文字と訳す． signed/unsigned 符号付き，符号なし sourc
自然言語処理におけるEmbeddingの方法一覧とサンプルコード - 機械学習 Memo φ(・ω・ )
概要 自然言語処理における単語や文章のEmbeddingの方法を勉強したので概要を記載しました。 また、学習済みモデルからEmbeddingベクトルを取得するサンプルソースコードも一部記載しました。 概要 Word2vec fastText GloVe Skip-thought SCDV USE ELMo BERT おわり 宣伝 Word2vec 似た意味の単語の周りには同じような単語が出現するとして、ある単語の周辺に出現する単語を予測するNNの隠れ層の重みを、ある単語のベクトルとしたもの。Doc2vecはWord2vecを文章に拡張したもの。 NNには以下のようなSkip-Gramのモデルが使われる。 Word2vecの元論文 : [1310.4546] Distributed Representations of Words and Phrases and their Composit
とほほのLISP入門 - とほほのWWW入門
LISPとは インストール Hello world REPL (Read-Eval-Print Loop) スクリプト実行 FASLファイル 実行ファイル コメント S式 Lispで扱える型 出力 文字列出力(write, write-line) 文字列・数字出力(print, princ, prin1) 改行出力(terpri) フォーマット(format) アトム(atom) 数値(number) 整数(integer) 小数(float) 分数(ratio) 複素数(complex) 文字列(string) 文字(character) シンボル(symbol) 真偽値(t/nil) リスト(list) リスト(list) 空リスト(()/nil) 要素抽出(car, cdr, first, second, ..., rest) リストの長さ(length) リスト連結(append)
50 Shades of Go: Traps, Gotchas, and Common Mistakes for New Golang Devs
50 Shades of Go: Traps, Gotchas, and Common Mistakes for New Golang Devs 50 Shades of Go in Other Languages Chinese Translation: blog post, segmentfault (by wuYin) - needs updates Another Chinese Translation: blog post (by Shadowwind LEY) - needs updates Russian Translation: blog post (by Ilia Ozhereliev, Mail.Ru Group Blog) - needs updates Overview Go is a simple and fun language, but, like any o
Preliminaries What Is xargs? It's an adapter between text streams and argv arrays, two essential concepts in shell. You pass it flags that specify how to split stdin. Then it generates arguments and invokes processes. Example: $ echo 'alice bob' | xargs -n 1 -- echo hi hi alice hi bob What's happening here? xargs splits the input stream on whitespace, producing 2 arguments, alice and bob. We passe
プログラミング言語C標準規格における改行文字(new-line character)と改行コードCR, LFとの関係性について。 まとめ： C標準規格ではプログラム内部で扱う「改行文字」と、外部ファイルにおける具体的なCR, LF等の「文字コード」を区別する。*1 *2 改行文字をファイル上でどう表現するかについて何ら規定しない。CR/LFを使わない方式も想定されている。 UNIX互換システムの場合、改行文字==改行コードLF(0x0A)となる。 Windows OSの場合、改行文字は2個の改行コードCRLF(0x0D 0x0A)で表現される。 上記のような改行コードによる行区切り表現だけでなく、メタ情報を利用した行区切り位置表現、長さプレフィックスと文字列データ表現、固定長レコードと特殊パディング文字表現（！）*3など、多種多様なテキストデータの表現方式を許容する。 仮想ターミナルなどの
Working with JSON data in GoogleSQL | BigQuery | Google Cloud
Send feedback Stay organized with collections Save and categorize content based on your preferences. Working with JSON data in GoogleSQL This document describes how to create a table with a JSON column, insert JSON data into a BigQuery table, and query JSON data. BigQuery natively supports JSON data using the JSON data type. JSON is a widely used format that allows for semi-structured data, becaus
日々変化するゆるふわフォーマットをBigQueryでおいしく料理する方法。Athenaユーザも必見だよ！ - CARTA TECH BLOG
3行まとめ 背景 データの流れ そのままコピーするだけのLambda 外部テーブルを使おう ゆるふわをゆるふわのまま扱う JSON Linesを1カラムのレコードとして取り込む 定期的に外部テーブルにクエリして結果を保存する まとめ 3行まとめ BigQueryはいいぞ 外部テーブルはすごいぞ Scheduled Queryも便利だぞ こんにちは。ひむ（@himu）です。 株式会社fluctでエンジニアとして働いていたり、ボルダリングしたりガチャを回したり健康で文化的な生活をしています。 fluctはインターネット広告プラットフォームのサービスなどを提供しており、毎日億単位の大量のイベントログが発生しています。 イベントログには、売上の計算に必要なデータから、アプリケーションを改善する上で必要なデータなど、様々なデータが入り混じっており、情報が追加されることも度々あります。 今回は、そんな
Python as a language is comparatively simple. And I believe, that you can learn quite a lot about Python and its features, just by learning what all of its builtins are, and what they do. And to back up that claim, I'll be doing just that. Just to be clear, this is not going to be a tutorial post. Covering such a vast amount of material in a single blog post, while starting from the beginning is p
Rewriting the Ruby parser
At Shopify, we have spent the last year writing a new Ruby parser, which we’ve called YARP (Yet Another Ruby Parser). As of the date of this post, YARP can parse a semantically equivalent syntax tree to Ruby 3.3 on every Ruby file in Shopify’s main codebase, GitHub’s main codebase, CRuby, and the 100 most popular gems downloaded from rubygems.org. We recently got approval to merge this work into C
こんにちは、そろそろ家の更新時期が迫ってきて引越し先の物件に悩んでいるしっぽくんです。最近業務でメールアドレスについて触れる機会があったので今回はそのお話をしようかと思います。 私自身あまり馴染みのなかった「RFC違反メールアドレス」について深堀っていく記事になりますので、ご興味あればご一読いただけると幸いです。 この記事で触れること RFC違反メールアドレスとはどういうことなのか HTML標準やバリデーションライブラリにおけるメールアドレスについて 違反しているメールアドレス?? さてこの中に仲間外れがあります。どれでしょう? 「test.test.@example.com」 「test.test@example.com」 「test..test@example.com」 正解は2です。これ以外は違反しているメールアドレスです!具体的にどんな違反メールアドレスなのでしょうか? 前置きを踏
Despite the click-bait title I hope you'll find this post generally illuminating, or at the very least a bit of fun! This article makes no claims that Haskell is "better" than C, nor does it make claims about the respective value of either language, or either implementation. It's simply an exploration into high-performance Haskell, with a few fun tricks and hacks along the way. You can find source
Links / Blogs → dragonsector.pl → vexillium.org Security/Hacking: j00ru's blog lcamtuf's blog invisible things (new) invisible things (old) liveoverflow's site /dev/null's site pi3's blog icewall's blog taviso's blog pawel's blog sandeep's blog koto's blog carstein's blog zaufana trzecia strona niebezpiecznik sekurak Reverse Eng./Low-Level: rewolf's blog gdtr spinning mirrors security news rev3rse
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
成果物のハッシュ値を保存・比較して余計なデプロイを行わないようにする for GitHub Actions
タイトル通りです。GitHub Actions において、成果物のハッシュ値を保存・比較して余計なデプロイを行わないようにする方法を記します。 TL;DR 対象 ビルド・デプロイを GitHub Actions で行っている 余計なデプロイはしたくない 静的サイトのビルド時に成果物のハッシュ値(sha256)を計算して、前回のデプロイ時と同じであればデプロイをスキップする ファイル 1 つ 1 つのハッシュ値を計算し、全ハッシュ値からさらにハッシュ値を計算する コマンド find <成果物のあるディレクトリパス> -type f -print0 | sort --zero-terminated | xargs -0 sha256sum | cut -d ' ' -f 1 | sha256sum | cut -d ' ' -f 1 デプロイ時に計算したハッシュ値は GitHub Action
Austin Z. Henley Associate Teaching Professor Carnegie Mellon University Let's make a Teeny Tiny compiler, part 1 5/5/2020 This is the first post in a three part series. Check out part 2 and part 3 when you are ready. It is a beautiful day outside, so let's make a compiler. You don't need any knowledge of how compilers work to follow along. We are going to use Python to implement our own programmi
syntaxdesign
One of the most recognizable features of a languages is its syntax. What are some of the things about syntax that matter? What questions might you ask if you were creating a syntax for your own language? Motivation A programming language gives us a way structure our thoughts. Each program, has a kind of internal structure, for example: How can we capture this structure? One way is directly, via pi
Published 08 May, 2020 under Release Notes ESLint v7.0.0 released We just pushed ESLint v7.0.0, which is a major release upgrade of ESLint. This release adds some new features and fixes several bugs found in the previous release. This release also has some breaking changes, so please read the following closely. Highlights There are several breaking changes in 7.0.0. We’ve created a migration guide
Regexide
Why XML Comments matter XML is a popular format for storing and sharing data. It was explicitly designed for people and programs to read and write data.[1] From spreadsheets to save states, most modern software and games parse and write XML. XML comments are special notes that parsers should not treat as data. XML comments start with <!-- and end with -->. Technically XML comments must not contain
haku
Haku A toy functional programming language based on literary Japanese. Is Haku for you? Haku lets you write programs that look very much like written Japanese. So you need to be familiar with written Japanese to program in Haku. I have added translations and explanations to the documentation. Haku is an experiment, not a practical programming language. Several of its features are rather contrary.
Note: I received a lot of great feedback from the discussions at Mastodon and Hacker News, so I've updated the post with some improvements to the font! I've also added some further examples and acknowledgements at the end. Syntax Highlighting in Hand-Coded Websites The problem I have been trying to identify practical reasons why hand-coding websites with HTML and CSS is so hard (by hand-coding, I
Delimiter-first code
Summary I argue for wider usage of delimiter-first in the code three friends [tic, tac, toe] becomes three friends ・tic ・tac ・toe. A new top-level syntax for programming languages is proposed to show advantages of this method. New syntax is arguably as simple, but more consistent, better preserves visual structure and solves some issues in code formatting. Related: comma-first formatting A well-kn
Text editors can be an interesting challenge to program. The types of problems that text editors need to solve can range from trivial to mind-bogglingly difficult. Recently, I have been on something of a spiritual journey to rework some internal data structures in an editor I have been building, specifically the most fundamental data structure to any text editor: the text. Table of Contents Resour
a more powerful, ultra fast, user-friendly, compatible grep (that is also completely free!) ugrep release 5.1 ugrep installs on MacOS: brew install ugrep Windows: winget install Genivia.ugrep Windows: choco install ugrep Windows: scoop install ugrep Alpine: apk add ugrep ugrep-doc Android Termux: pkg install ugrep Arch: pacman -S ugrep CentOS: dnf install ugrep Debian: apt-get install ugrep Fedora
Ruby Style Guide Ruby is the main language at Shopify. We are primarily a Ruby shop and we are probably one of the largest out there. Ruby is the go-to language for new web projects and scripting. We expect all developers at Shopify to have at least a passing understanding of Ruby. It's a great language. It will make you a better developer no matter what you work in day to day. What follows is a l
Simply Parse in C
by Chloe Kudryavtsev People are terrified of parsers and parsing. To the point of using magical libraries with custom syntaxes to learn just to get started. In the hopes of completely shattering this preconception, I will write a parser for the “ini” file format in about 150 lines of pure and readable ISO C99. Furthermore, this parser will be something that's nice to use and has error correcting f
Hacking with Environment Variables Interesting environment variables to supply to scripting language interpreters Introduction On a recent project we gained the ability to specify environment variables but not the process that was executed. We were also unable to control the contents of a file on disk, and bruteforcing process identifiers (PIDs) and file descriptors found no interesting results, e
Alexis Beingessner's Text Rendering Hates You, published exactly a month ago today, hits very close to my heart. Back in 2017, I was building a rich text editor in the browser. Unsatisfied with existing libraries that used ContentEditable, I thought to myself "hey, I'll just reimplement text selection myself! How difficult could it possibly be?" I was young. Naive. I estimated it would take two we
Prettier 2.3. In which assignments are consistent, short keys non-breaking, and Handlebars official · Prettier
This release focuses on fixing long-standing issues in the JavaScript printer. Be warned that, unfortunately, reformatting a project with the new version might result in quite a big diff. If you don’t use ignoreRevsFile to hide such wholesale changes from git blame, it might be about time. A remarkable milestone is the long-awaited release of the Ember / Handlebars formatter. It’s supposed to be t
"�[31m"?! ANSI Terminal security in 2023 and finding 10 CVEs This paper reflects work done in late 2022 and 2023 to audit for vulnerabilities in terminal emulators, with a focus on open source software. The results of this work were 10 CVEs against terminal emulators that could result in Remote Code Execution (RCE), in addition various other bugs and hardening opportunities were found. The exact c
S3へ出力したCloudWatch LogsのデータをS3 SelectとAthenaで確認してみた | DevelopersIO
Kinesis Data Firehose介し、S3へ出力したCloudWatch LogsのデータをS3 SelectとAthenaで確認してみました。 Kinesis Data Firehoseを使いCloudWatch LogのデータをS3に出力することが可能です。S3をデータソースにしたデータの確認方法は多々あると思いますが、ここではS3 SelectとAthenaを利用しログデータを確認してみたいと思います。本エントリでは、環境構築については割愛していますので、構築については以下ブログを参考にしてください。 CloudWatch LogsのログデータをKinesis Data Firehose経由でS3に出力する なお、ここではS3へ出力されたログデータはAurora監査ログを利用しています。 S3 Select 構成 Kinesis Data Firehose設定 配信ストリー
LPT_LISA
Linux Productivity Tools Ketan M. (km0@ornl.gov) Oak Ridge National Laboratory 1 LISA19 October 2019 Portland, OR, USA Table of Contents • Part 1: Overview and Logistics • Part 2: Basics • Part 3: Streams, pipe and redirection • Part 4: Classic Tools: find, grep, awk, sed • Part 5: Session Management: tmux • Part 6: ssh: config and tunneling • Part 7: Bash Tools • Part 8: Miscellaneous Utilities •
Two years ago, I had a blog entry describing falling in love with Rust. Of course, a relationship with a technology is like any other relationship: as novelty and infatuation wears off, it can get on a longer term (and often more realistic and subdued) footing — or it can begin to fray. So well one might ask: how is Rust after the honeymoon? By way of answering that, I should note that about a yea
These are developer-focused instructions that cover posting messages to Slack via APIs. For user instructions on message formatting in your Slack client, refer to this Help Center article. App surfaces such as messages, modals, or Home tabs can contain all types of textual treasures. The text itself can be formatted and placed inside blocks to create rich message layouts. The Block Kit elements th
PowerShell: the object-oriented shell you didn’t know you needed
PowerShell is an interactive shell and scripting language from Microsoft. It’s object-oriented — and that’s not just a buzzword, that’s a big difference to how the standard Unix shells work. And it is actually usable as an interactive shell. Getting Started PowerShell is so nice, Microsoft made it twice. Specifically, there concurrently exist two products named PowerShell: Windows PowerShell (5.1)
First there was cooperative multiprocessing. Then there were processes. An operating system could run multiple processes, each performing a series of sequential, blocking actions. Then came threads. A single processes could spawn off multiple threads, each performing its own series of sequential, blocking actions. (And really, the story starts earlier, with hardware interrupts and the like, but ho
Cognition
Lisp programmers claim that their system of s-expression code in addition to its featureful macro system makes it a metaprogrammable and generalized system. This is of course true, but there's something very broken with lisp: metaprogramming and programming aren't the same thing, meaning there will always be rigid syntax within lisp (its parentheses or the fact that it needs to have characters tha
Do Not Use '>' in Your Command Prompt (and How to Stay Safe in Shell) - Tanel Poder Consulting
Do Not Use '>' in Your Command Prompt (and How to Stay Safe in Shell) Over the years of troubleshooting performance problems in the Unix/Linux world, I have seen multiple cases where a regularly used command line tool in a customer server just stops working for some reason. The tool just returns immediately, doing absolutely nothing. No output printed, no coredumps and the exit code is zero (succe
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パスワードの1文字目に「~(チルダ)」を使って痛い目にあった - Qiita
Ubuntu 24.04 LTS サーバ構築手順書
An Opinionated Guide to xargs
改行コード(CR/LF)と改行文字と標準C - yohhoyの日記
Understanding all of Python, through its builtins
違反しているメールアドレスってなんだ？！ - Qiita
Beating C with 80 lines of Haskell: wc
xz/liblzma: Bash-stage Obfuscation Explained
Let's make a Teeny Tiny compiler, part 1
ESLint v7.0.0 released - ESLint - Pluggable JavaScript Linter
Font with Built-In Syntax Highlighting
Text Editor Data Structures
The ugrep file pattern searcher
Ruby Style Guide
Hacking with Environment Variables - elttam
Text Editing Hates You Too – Lord.io
"�[31m"?! ANSI Terminal security in 2023 and finding 10 CVEs
Rust after the honeymoon – The Observation Deck
Formatting text for app surfaces
Different levels of async in Rust