#regex
6 pages tagged regex.
findstr
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.
sed
Non-interactive text transformation. Substitution, deletion, insertion, address ranges, in-place editing, and multi-line patterns with practical recipes.
re
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.
PCRE
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.
grep
Search files and streams using fixed strings, extended regex, or PCRE. Covers all major flags, context, recursive search, and pipeline 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.