Programs Summary (The GNU Awk User’s Guide)

The programs provided in this chapter continue on the theme that reading programs is an excellent way to learn Good Programming.
Using ‘#!’ to make awk programs directly runnable makes them easier to use. Otherwise, invoke the program using ‘awk -f …’.
Reimplementing standard POSIX programs in awk is a pleasant exercise; awk’s expressive power lets you write such programs in relatively few lines of code, yet they are functionally complete and usable.
One of standard awk’s weaknesses is working with individual characters. The ability to use split() with the empty string as the separator can considerably simplify such tasks.
The examples here demonstrate the usefulness of the library functions from A Library of awk Functions for a number of real (if small) programs.
Besides reinventing POSIX wheels, other programs solved a selection of interesting problems, such as finding duplicate words in text, printing mailing labels, and finding anagrams.