Advanced shell scripting magic

This is the dark magic section of the chapter. It will demonstrate advanced shell scripting by taking the preceding lessons and features, and converting them into what could be considered a small program.

Here be dragons, ye be warned

A simple piece of introductory code is great to get a feel for the flavor of a language, but we're going to introduce some dark magic in the form of some complex utility functions that can be helpful in everyday situations. We'll use a lineinfile function to insert arbitrary text into a file—it's not a full-featured application, just enough to help ensure some simple text is injected into a file. The second function, ncz, leverages bash IP...