Go to the first, previous, next, last section, table of contents.

Using This Book

The term awk refers to a particular program, and to the language you use to tell this program what to do. When we need to be careful, we call the program "the awk utility" and the language "the awk language." The term gawk refers to a version of awk developed as part the GNU project. The purpose of this book is to explain both the awk language and how to run the awk utility.

The main purpose of the book is to explain the features of awk, as defined in the POSIX standard. It does so in the context of one particular implementation, gawk. While doing so, it will also attempt to describe important differences between gawk and other awk implementations. Finally, any gawk features that are not in the POSIX standard for awk will be noted.

This book has the difficult task of being both tutorial and reference. If you are a novice, feel free to skip over details that seem too complex. You should also ignore the many cross references; they are for the expert user, and for the on-line Info version of the document.

The term awk program refers to a program written by you in the awk programming language.

See section Getting Started with awk, for the bare essentials you need to know to start using awk.

Some useful "one-liners" are included to give you a feel for the awk language (see section Useful One Line Programs).

Many sample awk programs have been provided for you (see section A Library of awk Functions; also see section Practical awk Programs).

The entire awk language is summarized for quick reference in section gawk Summary. Look there if you just need to refresh your memory about a particular feature.

If you find terms that you aren't familiar with, try looking them up in the glossary (see section Glossary).

Most of the time complete awk programs are used as examples, but in some of the more advanced sections, only the part of the awk program that illustrates the concept being described is shown.

While this book is aimed principally at people who have not been exposed to awk, there is a lot of information here that even the awk expert should find useful. In particular, the description of POSIX awk, and the example programs in section A Library of awk Functions, and section Practical awk Programs, should be of interest.

Dark Corners

Who opened that window shade?!?
Count Dracula

Until the POSIX standard (and The Gawk Manual), many features of awk were either poorly documented, or not documented at all. Descriptions of such features (often called "dark corners") are noted in this book with "(d.c.)". They also appear in the index under the heading "dark corner."

Go to the first, previous, next, last section, table of contents.