Original Summary

Greediness: <.+> against <div>hi</div><span>x</span> matches the whole string, because + grabs as much as it can while still letting the rest of the pattern succeed. <.+?> is lazy and stops at the first >. Catastrophic backtracking: nested quantifiers like (a+)+b against a long run of a's with no b make the engine try an exponential number of paths before failing. That's how a regex freezes a tab, or takes down a request in production. I built a free tester around catching both: live match highlighting, a token-by-token explainer, a debugger for "matches too much/nothing", and a performance analyzer that flags the nested-quantifier shapes. There are also replace/split modes, a visual builder, and a pattern library. Limitation: it uses JavaScript's built-in RegExp, so results match JS code, but it isn't a PCRE or Python flavor tester. Runs entirely in the browser, no signup: https://www.forgeplug.com/tools/regex-tester What's the nastiest regex bug you've hit?   submitted by   /u/Acceptable_Day_537 [link]   [comments]

  • 情报分类：硬件与数码
  • 分类依据：内容涉及硬件、数码产品或通信卡
  • 信息来源：Reddit · SideProject
  • 发布时间：2026/10/17 13:08:38