book

The AWK Programming Language, 2nd Edition

by Alfred V. Aho, Brian W. Kernighan, Peter J. Weinberger

September 2023

Intermediate to advanced

240 pages

7h 40m

English

Addison-Wesley Professional

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Organization of the BookThe ExamplesEvolution of AwkAcknowledgmentsAcknowledgments for the First Edition
1.1 Getting Started1.2 Simple Output1.3 Formatted Output1.4 Selection1.5 Computing with Awk1.6 Control-Flow Statements1.7 Arrays1.8 Useful One-liners1.9 What Next?
2.1 Personal Computation2.2 Selection2.3 Transformation2.4 Summarization2.5 Personal Databases2.6 A Personal Library2.7 Summary

3.1 The Sinking of the Titanic3.2 Beer Ratings3.3 Grouping Data3.4 Unicode Data3.5 Basic Graphs and Charts3.6 Summary
4.1 Data Transformation and Reduction4.2 Data Validation4.3 Bundle and Unbundle4.4 Multiline Records4.5 Summary
5.1 Generating Reports5.2 Packaged Queries and Reports5.3 A Relational Database System5.4 Summary
6.1 Random Text Generation6.2 Interactive Text-Manipulation6.3 Text Processing6.4 Making an Index6.5 Summary
7.1 An Assembler and Interpreter7.2 A Language for Drawing Graphs7.3 A Sort Generator7.4 A Reverse-Polish Calculator7.5 A Different Approach7.6 A Recursive-Descent Parser for Arithmetic Expressions7.7 A Recursive-Descent Parser for a Subset of Awk7.8 Summary
8.1 Sorting8.2 Profiling8.3 Topological Sorting8.4 Make: A File Updating Program8.5 Summary
9.1 Awk as a Language9.2 Performance9.3 Conclusion
A.1 PatternsA.2 ActionsA.3 User-Defined FunctionsA.4 OutputA.5 InputA.6 Interaction with Other ProgramsA.7 Summary

Content preview from The AWK Programming Language, 2nd Edition

5 Reports and Databases

This chapter shows how Awk can be used to extract information and generate reports from data stored in files. The emphasis is on tabular data, but the techniques apply to more complex forms as well. The theme is the development of programs that can be used with one another. We will see a number of common data-processing problems that are hard to solve in one step, but easily handled by making several passes over the data.

The first part of the chapter deals with generating reports by scanning a single file. Although the format of the final report is of primary interest, there are complexities in the scanning too. The second part of the chapter describes one approach to collecting data from several interrelated files. ...