Text Processing

grep, sed, and awk cheat sheet — the "three text-processing swords": grep matches, sed rewrites in place, awk extracts and aggregates by column. Each tool's highest-frequency forms plus the classic pipeline (grep to filter, sed to substitute, awk to summarize) for anyone living in logs, configs, and CSV.

An awk reference covering built-in variables such as NR and NF, conditionals and loops, per-column extraction and aggregation, string functions, and typical patterns for processing logs and CSV.

Batch-editing configs, redacting logs, and in-place replacement with a backup are sed's territory — the "rewrite" partner to awk's "aggregate". This reference covers substitution, deletion, insert/append, addressing by range, extended regex, and the -i in-place edit with -i.bak backup.