The awk utility interprets a special-purpose programming language
that makes it possible to handle simple data-reformatting jobs
with just a few lines of code.
Gawk is the GNU implementation of awk. It is upwardly compatible with
Brian Kernighan's version of Unix awk. It is almost completely compliant
with the 2018 POSIX 1003.1 standard for awk.
This manual (gawk) is available in https://www.gnu.org/software/gawk/manual/.