A good introductory tutorial on awk. I have heard a lot about it, even used it a couple of times in shell scripts but never programmed using it. Check this article to learn more about it.
The awk programming language often gets overlooked for Perl, which is a more capable language. Out in the real world, however awk is found even more ubiquitously than Perl. It also has a smaller learning curve than Perl does, and awk can be used almost everywhere in system monitoring scripts, where efficiency is key. This brief tutorial is designed to help you get started in awk programming.
The awk language is a small, C-style language designed for the processing of regularly formatted text. This usually includes database dumps and system log files. It’s built around regular expressions and pattern handling, much like Perl is. In fact, Perl is considered to be a grandchild of the awk language.
Complete Article: An Introduction to awk