I wrote a book on GNU awk one-liners: https://learnbyexample.github.io/learn_gnuawk/ https://learnbyexample.github.io/learn_gnuawk/ There's plenty of examples

I wrote a book on GNU awk one-liners: https://learnbyexample.github.io/learn_gnuawk/ https://learnbyexample.github.io/learn_gnuawk/ There's plenty of examples and exercises, plus an entire chapter dedicated to regular expressions.