Regex character “$” doesn't mean “end-of-string”
This article is about a bit of surprising behavior I recently discovered using Python's regex module (re) while developing SBOM tooling for CPython. Folks who've worked with regular expressions before might know about ^ meaning "start-of-string" and correspondingly see $ as "end-of-string". So the pattern cat$ would match the string "lolcat" but not "internet cat video". The behavior of ^ made me
正規表現でのURLのチェックとバイパス | 技術者ブログ | 三井物産セキュアディレクション株式会社
最近はMBSDでWebアプリケーションスキャナの開発をしている寺田です。 Webアプリケーションを開発していると、セキュリティの観点でURLをチェックしなければならないことがしばしばあります。本日の記事では、そのようなURLのチェックを如何に行うか、正規表現を使う場合の注意点や、バイパス方法などについて書きたいと思います。 本記事で想定するのは、ブラウザからパラメータとして来るURLをチェックしてリダイレクトやリンクのURL等として使ったり、ブラウザから来たOriginヘッダ等のURLをチェックしてアクセス制御をするケースです。その中でも、以下のようにサブドメイン部分（★の部分）を可変にする状況を主に想定します。 https://★.example.jp/… よく使われてそうなチェック用の正規表現と、そのバイパスは以下のとおりです。 正規表現: ^https://.+\.example\.
Speeding up the JavaScript ecosystem - one library at a time
Whilst the trend is seemingly to rewrite every JavaScript build tool in other languages such as Rust or Go, the current JavaScript-based tools could be a lot faster. The build pipeline in a typical frontend project is usually composed of many different tools working together. But the diversification of tools makes it a little harder to spot performance problems for tooling maintainers as they need
The regex [,-.]
I stumbled on this regex recently: \d{2}[,-.]\d{2}. The intention is clear enough: match two sets of two digits separated by a comma, a dash, or a period. Of course, it shouldn’t work. Dashes in character classes are special because they’re used for ranges (like [a-z] to match lower-case ASCII letters). If you want - in a character class you put it at the beginning, or the end, never the middle. S
![The regex [,-.]](https://cdn-ak-scissors.b.st-hatena.com/image/square/35b4c7818be85249d8df43989c3d5f3748c37c08/height=288;version=1;width=512/https%3A%2F%2Fpboyd.io%2Fposts%2Fcomma-dash-dot%2Fcode.png)
re2c — re2c 3.0 documentation
re2c is a free and open-source lexer generator for C/C++, Go and Rust with a focus on generating fast code. It compiles regular expression specifications to deterministic finite automata and encodes them in the form of conditional jumps in the target language. This approach is generally faster than table-based lexers, and the generated code is easier to debug and understand. A flexible user interf
GitHub - CAFxX/regexp2go: Compile Go regular expressions to Go code
regexp2go is an alternate backend for the regexp package that allows to perform ahead-of-time compilation of regular expressions to Go code. This is similar in spirit to re2go, but aiming for compatibility with the Go regexp package. ⚠️ This is an experimental PoC that currently implements only a subset of the functionalities and optimizations present in the full regexp package. Rather importantly
RegEx match open tags except XHTML self-contained tags
You can't parse [X]HTML with regex. Because HTML can't be parsed by regex. Regex is not a tool that can be used to correctly parse HTML. As I have answered in HTML-and-regex questions here so many times before, the use of regex will not allow you to consume HTML. Regular expressions are a tool that is insufficiently sophisticated to understand the constructs employed by HTML. HTML is not a regular
リリース、障害情報などのサービスのお知らせ
最新の人気エントリーの配信
j次のブックマーク
k前のブックマーク
lあとで読む
eコメント一覧を開く
oページを開く
Regexper
Regular Expressions make me feel like a powerful wizard - and that's not a good thing
https://www.autoregex.xyz/
Regex Vis
Regex Hunting
ReDoS 検出の最先端 recheck の紹介 / State of the Art of ReDoS Detection
On Regular Expressions · @radekmie’s take on IT and stuff
GitHub - learnbyexample/py_regular_expressions: Learn Python Regular Expressions step by step from beginner to advanced levels
GitHub - pemistahl/grex: A command-line tool and Rust library with Python bindings for generating regular expressions from user-provided test cases
GitHub - m-ender/retina: A regex-based programming language.
i Hate Regex - The Regex Cheat Sheet
GitHub - iogf/crocs: Python to Regex. Regex to Python. The yRegex for humans.
Regex Dictionary by Lou Hevly