The awk utility interprets a special-purpose programming language that makes it easy to handle simple data-reformatting jobs.
The GNU implementation of awk is called gawk; if you invoke it with the proper options or environment variables, it is fully compatible with the POSIX1 specification of the awk language and with the Unix version of awk maintained by Brian Kernighan. This means that all properly written awk programs should work with gawk. So most of the time, we don’t distinguish between gawk and other awk implementations.
