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#regex (6)

Cheat sheets (6)

findstr — Search Text in Files

Search for string patterns inside files or piped input on Windows — the built-in grep equivalent for cmd.exe, with support for regular expressions, case-insensitive matching, and recursive directory searches.
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grep — Pattern Search

Search files and streams using fixed strings, extended regex, or PCRE. Covers all major flags, context, recursive search, and pipeline patterns.
grep regex search text-processing cli pipes web-researched

PCRE — Perl Compatible Regular Expressions

PCRE2 syntax reference — character classes, quantifiers, anchors, groups, lookarounds, backreferences, flags, and advanced features used in grep, sed, nginx, PHP, and dozens of other tools.
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sed — Stream Editor

Non-interactive text transformation. Substitution, deletion, insertion, address ranges, in-place editing, and multi-line patterns with practical recipes.
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re — Python Regular Expressions

Python's built-in regex module — compile vs not, match/search/findall/finditer/sub, named groups, lookarounds, verbose mode (re.X), and how it differs from PCRE.
python stdlib regex re patterns

Regular Expressions

JavaScript has built-in RegExp support (ES2018+ with named groups, lookbehind, dotAll). Covers literal syntax, flags, character classes, methods, named captures, and common patterns.
javascript regex language