The Trinity Part 1: Grep, the Precision Scout
Grep is the right tool when you want to find not only files, but even the contents of files in a directory. This post is going to explore finding by inversion.
Text-Processing
The Trinity Part 2: Sed, the Surgeon's Blade
Make your life simple by using sed, the stream editor, to make fast edits in one or more files
The Trinity Part 3: Awk, the Master Architect
A file is treated as a set of records, and each line is split into fields. This is the whole idea of awk: seeing data as an organised set of entities.