Part III:
Moving Beyond Standard awk with gawk ¶

12 Advanced Features of gawk ¶

Write documentation as if whoever reads it is a violent psychopath who knows where you live.

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 Web page, is described in full detail, along with the basics of TCP/IP networking. We then see how gawk can profile an awk program, making it possible to tune it for performance. Next, we present an experimental feature that allows you to preserve the values of awk variables and arrays between runs of gawk. Finally, we discuss the philosophy behind gawk’s extension mechanism.

Additional advanced features are discussed in separate chapters of their own:

• Internationalization with gawk, discusses how to internationalize your awk programs, so that they can speak multiple national languages.
• Debugging awk Programs, describes gawk’s built-in command-line debugger for debugging awk programs.
• Arithmetic and Arbitrary-Precision Arithmetic with gawk, describes how you can use gawk to perform arbitrary-precision arithmetic.
• Writing Extensions for gawk, discusses the ability to dynamically add new built-in functions to gawk.

• Allowing Nondecimal Input Data
• Boolean Typed Values
• Controlling Array Traversal and Array Sorting
• Two-Way Communications with Another Process
• Using gawk for Network Programming
• Profiling Your awk Programs
• Preserving Data Between Runs
• Builtin Features versus Extensions
• Summary