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

6 Processing Words

The programs in this chapter share a common theme: the manipulation of natural language text. The examples include programs that generate random words and sentences, that carry on limited dialogues with the user, and that process text. Most are toys, of value mainly as illustrations, but some of the document preparation programs are in regular use.

6.1 Random Text Generation

Programs that generate random data have many uses. Such programs can be created using the built-in function rand, which returns a pseudo-random number each time it is called. The rand function starts generating random numbers from the same seed each time a program using it is invoked, so if you want a different sequence each time, you must call srand( ...