Regular

Regular Expressions in sed

How sed matches text using Basic and Extended Regular Expressions, including anchors, character classes, quantifiers, and the escaping rules that trip people u…

Patterns and Regular Expressions

AWK programs are pattern-action pairs; patterns can be regular expressions, relational tests, or ranges that decide which records an action runs on.

Regular Expressions in VBA

Using the VBScript RegExp object to match, extract, and replace text patterns in VBA, including groups, global matching, and common gotchas.

Regular Expressions in Tcl

How to match, extract, and rewrite text patterns in Tcl using the regexp and regsub commands and Tcl's Advanced Regular Expression syntax.

Regular Expressions in Perl

Learn how Perl's built-in regex engine lets you match, capture, and substitute text patterns using operators like m//, s///, and tr///.

Regular Expressions in Python

Pattern matching and text processing using Python's re module -- syntax, key functions, and common pitfalls.

Regular Expressions in PHP

Learn PCRE-based pattern matching in PHP with preg_match, preg_replace, and preg_match_all for validating, extracting, and transforming text.

grep and Regular Expressions

Master text searching with grep and the regular expression syntax that powers it, from basic literal matches to extended regex patterns and useful flags.