Write documentation as if whoever reads it is a violent psychopath who knows where you live.
—Steve English, as quoted by Peter Langston
This chapter discusses advanced features in
gawk. It’s a bit of a “grab bag” of items that are
otherwise unrelated to each other. First, we look at a command-line option that allows
gawk to recognize nondecimal numbers in input
data, not just in
awk programs. Then,
gawk’s special features for sorting
arrays are presented. Next, two-way I/O, discussed briefly in earlier parts
of this book, is described in full detail, along with the basics of TCP/IP
networking. Finally, we see how
program, making it possible to tune it for performance.
Additional advanced features are discussed in separate chapters of their own:
Chapter 13, Internationalization with gawk, discusses how to internationalize your
awk programs, so that they can speak
multiple national languages.
Chapter 14, Debugging awk Programs, describes
gawk’s built-in command-line debugger
Chapter 15, Arithmetic and Arbitrary-Precision Arithmetic with gawk, describes how you can use
gawk to perform arbitrary-precision
Chapter 16, Writing Extensions for gawk,
discusses the ability to dynamically add new built-in functions to
If you run
gawk with the
--non-decimal-data option, you can have nondecimal
values in your input data:
echo 0123 123 0x123 |>
gawk --non-decimal-data ...