This article introduces the Linux stream editor sed, explains its working principle, basic syntax, address ranges, and editing commands, and provides practical exercises demonstrating common text manipulation tasks such as printing even lines, commenting specific patterns, case conversion, and file modifications.
This article explains how to list directory names ranging from 00 to 12 in a log folder by enabling Bash's extglob option and applying a regular‑expression‑style pattern with the ls command.
The article demonstrates how to split a space‑separated "validperiods" column into separate begin, end, and price fields in PostgreSQL using string_to_array, to_timestamp, regexp_replace, and unnest to transform the data into a readable tabular format.
This article explains the most common regular‑expression metacharacters, their meanings, and shows how to combine them in real‑world grep commands to match patterns such as lines starting with 30, containing 70 or 1800, and validating email addresses.
This article provides a comprehensive guide to Python's regular expression support, covering fundamental concepts, greedy vs. non‑greedy quantifiers, escape handling, match objects, pattern compilation, and the full suite of re module functions with practical code examples.
This article introduces Python's regular expression module, explaining raw string literals, the differences between match, search, and findall methods, and how to use numbered and named groups to extract specific parts of matched text, complete with practical code examples.
This article explains the differences between grep, egrep, and fgrep, details common options and character classes, and demonstrates how to use regular‑expression metacharacters, grouping, and backreferences for powerful text filtering on Linux servers.
This article provides a comprehensive, English-language reference of common regular expression metacharacters, explaining their meanings, usage rules, and examples for pattern matching in programming languages such as JavaScript.
