Effective AWK Programming

Amazon.com

For anyone who writes scripts in the awk family of languages, the third edition of Effective awk Programming provides an in-depth guide to processing text files with plenty of working sample code. Whether you are starting out with awk or are an experienced developer, this book will help you extend the reach of your awk scripts.

This tutorial covers the entire spectrum of awk script development: From the basics of opening, searching, and transforming text files, to a comprehensive tutorial for regular expressions, to more advanced features like internetworking. The focus is on the practical side of creating and running awk scripts, and there's plenty of hands-on advice for installing and running today's awk (and gawk).

The book begins with the fundamentals of awk for opening and transforming text flat files. The coverage of regular expressions, from simple rules for matching text to more advanced options, is particularly solid. You learn how to add variables and expressions for more intelligent awk scripts, plus how to parse data into records and fields. You'll also find out how to redirect output from awk scripts to other programs, a useful technique that can cause awk to get a lot more done in real applications.

Later, you learn several valuable sample awk scripts that mimic existing Unix utilities (like grep, id, and split), plus samples for counting words in documents and printing mailing labels, and even a stream editor. This grab bag of sample code lets you try out the techniques presented earlier in the book. Other sections look at support for networking in today's gawk; for example, how gawk can read and write to URLs on the network almost just as easily as local files. Full sample code will teach the beginner or expert how to get productive with networks and awk. Final appendices trace the evolution of the awk language and show you how to download and install gawk.

Suitable for beginner and experienced awk developers, Effective awk Programming, Third Edition, is an extremely worthwhile source of information on a wide range of programming techniques for today's awk. --Richard Dragan

Topics covered:

• Introduction to the awk programming language
• Running awk scripts
• Basic file processing
• Tutorial for regular expressions
• Strategies for matching text
• Dynamic regular expressions
• Parsing data into records and lines (including separating fields and handling multiple-line records)
• Using print and printf for printed output with awk (including format specifiers)
• Redirecting awk scripts output to other processes
• Basic and advanced awk expressions (constants, variables, and function calls)
• Patterns
• Shell variables and actions
• Arrays (including multidimensional arrays and sorting)
• Built-in and custom awk functions
• Internationalizing and localizing awk scripts
• Advanced gawk (communicating with other processes and networking programming)
• Running awk and gawk
• Sample awk scripts
• Internetworking with awk
• History and evolution of awk
• Downloading and installing gawk

Reviews From AMAZON.COM

Most Complete Coverage of Awk

Awk is one of those handy Unix tools with which you can easily impress people. Using a simple

/pattern/ { action }

syntax, you can construct powerful one-liners. Do you want to how much time in total you spent surfing the Internet? Here it is:

awk '/Connect time/ { s += $8 } END { print s }' /var/log/messages

It doesn't get much shorter in any other programming language, does it? Need to strip text of HTML tags? Need a frequency count of words in a text? Awk is the perfect tool for tasks like this. With its pattern-action structure, powerful regular expression mechanism, associative arrays and basic program flow control, it provides a powerful tool for manipulating flat text files. Even though other scripting languages may be richer in features, there exists a niche where Awk is just the right tool to do the job.

Arnold Robbins, the author of this book as well as of several other books on Awk, serves also as the maintainer of GNU Awk (gawk for short), the most influential version of Awk available today. With the version 3.10, released in 2001, GNU Awk became richer for a handful of new extensions over traditional Awk, most important among them are the TCP/IP networking and the support for internationalization. All new extensions are described in the book. How successful these new extensions will be is doubtful, however. Networking scripting niche is already well covered with Perl and Python, and internationalization doesn't really matter much in short throw-away scripts Awk is usually used for.

With all due respect to the creators of Awk and their book (Alfred V. Aho, Peter J. Weinberger, Brian W. Kernighan, The Awk Programming Language, Addison-Wesley, 1988), I have to say that "Effective Awk Programming" is probably the best Awk tutorial on the market today. If you are serious about learning Awk, you shouldn't be without it. If you are still hesitating whether it wouldn't be wiser investing those 28 USD elsewhere, here is chance to read it before you buy it: install GNU Awk 3.10, and the Texinfo source of the book comes with it. But sooner or later you will find O'Reilly RepKover binding too tempting...

awk programming

This book is being picked up by the O'Reilly people. I have many of the O'Reilly books on my book shelf. There will be a third edition due out in July with Robbins as the author. I read though this book and thought it as good or better than the "Sed & awk" book that O'Reilly presently has out. Robbins is also an author on this book. I thought the book to be better than the "AWK programming language" by Aho, Kerninghan and Weinberger, the original authors of the AWK language. I recommend the book to beginers as I am.