ULTRIX Guide to the nawk Utility

This document is a "Guide to the nawk Utility", published by Digital Equipment Corporation in June 1990 for ULTRIX Version 4.0 or higher.

It serves as both a tutorial and a reference manual for nawk, which is described as an enhanced version of the awk text-processing utility and programming language.

Aimed at intermediate users of the ULTRIX system, the manual covers:

• Basic Concepts: Explaining data files (records and fields), the structure of nawk programs (patterns and actions), and how to run them from the command line or program files.
• Core Programming: Details on arithmetic operations, formatted output using printf, the use of variables, and built-in mathematical functions.
• Text Processing: Comprehensive coverage of pattern matching, regular expressions (including metacharacters and combining conditions), and string manipulation techniques.
• Control Flow: Instructions on using if, while, for, next, and exit statements to create more powerful programs.
• Advanced Features: Information on arrays (integer, generalized, multidimensional), user-defined functions (including recursion and argument passing), and enhancing nawk programs with getline (for explicit input reading) and system (for executing shell commands).

The guide teaches users how to leverage nawk for productive programming tasks such as displaying information, performing calculations, preparing reports, and analyzing text.