Book Image

Mastering Go – Third Edition - Third Edition

By : Mihalis Tsoukalos
5 (2)
Book Image

Mastering Go – Third Edition - Third Edition

5 (2)
By: Mihalis Tsoukalos

Overview of this book

Mastering Go is the essential guide to putting Go to work on real production systems. This freshly updated third edition includes topics like creating RESTful servers and clients, understanding Go generics, and developing gRPC servers and clients. Mastering Go was written for programmers who want to explore the capabilities of Go in practice. As you work your way through the chapters, you’ll gain confidence and a deep understanding of advanced Go concepts, including concurrency and the operation of the Go Garbage Collector, using Go with Docker, writing powerful command-line utilities, working with JavaScript Object Notation (JSON) data, and interacting with databases. You’ll also improve your understanding of Go internals to optimize Go code and use data types and data structures in new and unexpected ways. This essential Go programming book will also take you through the nuances and idioms of Go with exercises and resources to fully embed your newly acquired knowledge. With the help of Mastering Go, you’ll become an expert Go programmer by building Go systems and implementing advanced Go techniques in your projects.
Table of Contents (17 chapters)
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Updating the phone book application

The functionality that is added to this new version of the phone book utility is the following:

  • The CSV file path can be optionally given as an environment variable named PHONEBOOK
  • The list command sorts the output based on the surname field

Although we could have given the path of the CSV file as a command-line argument instead of the value of an environment variable, it would have complicated the code, especially if that argument was made optional. More advanced Go packages such as viper, which is presented in Chapter 6, Telling a UNIX System What to Do, simplify the process of parsing command-line arguments with the use of command-line options such as -f followed by a file path or --filepath.

The current default value of CSVFILE is set to my home directory on a macOS Big Sur machine—you should change that default value to fit your needs or use a proper value for the PHONEBOOK environment variable.