I noticed that Eric Wendelin wrote an article "awk is a beautiful tool." In this article he said that it was best to introduce Awk with practical examples. I totally agree with Eric. When I was learning Awk, I first went through Awk - A Tutorial and Introduction by Bruce Barnett, which was full of examples to try out; then I created an Awk cheat sheet to have the language reference in front of me;
![Awk One-Liners Explained, Part I: File Spacing, Numbering and Calculations](https://cdn-ak-scissors.b.st-hatena.com/image/square/deedb67dac356f5b6b3e505320e371d9688b51b1/height=288;version=1;width=512/https%3A%2F%2Fcatonmat.net%2Fimages%2Fcatonmat-preview-image.png)