Chapter 11. A Flock of awks

In the previous four chapters, we have looked at POSIX awk, with only occasional reference to actual awk implementations that you would run. In this chapter, we focus on the different versions of awk that are available, what features they do or do not have, and how you can get them.

First, we'll look at the original V7 version of awk. The original awk lacks many of the features we've described, so this section mostly describes what's not there. Next, we'll look at the three versions whose source code is freely available. All of them have extensions to the POSIX standard. Those that are common to all three versions are discussed first. Finally, we look at three commercial versions of awk.