Book Image

Mastering Go - Second Edition

By : Mihalis Tsoukalos
Book Image

Mastering Go - Second Edition

By: Mihalis Tsoukalos

Overview of this book

Often referred to (incorrectly) as Golang, Go is the high-performance systems language of the future. Mastering Go, Second Edition helps you become a productive expert Go programmer, building and improving on the groundbreaking first edition. Mastering Go, Second Edition shows how to put Go to work on real production systems. For programmers who already know the Go language basics, this book provides examples, patterns, and clear explanations to help you deeply understand Go’s capabilities and apply them in your programming work. The book covers the nuances of Go, with in-depth guides on types and structures, packages, concurrency, network programming, compiler design, optimization, and more. Each chapter ends with exercises and resources to fully embed your new knowledge. This second edition includes a completely new chapter on machine learning in Go, guiding you from the foundation statistics techniques through simple regression and clustering to classification, neural networks, and anomaly detection. Other chapters are expanded to cover using Go with Docker and Kubernetes, Git, WebAssembly, JSON, and more. If you take the Go programming language seriously, the second edition of this book is an essential guide on expert techniques.
Table of Contents (15 chapters)

Creating a web client in Go

In this section, you will learn more about developing web clients in Go. The name of the web client utility is webClient.go, and it is going to be presented in four parts.

The first part of webClient.go contains the following Go code:

package main 
 
import ( 
    "fmt" 
    "io" 
    "net/http" 
    "os" 
    "path/filepath" 
) 

The second part of webClient.go is where you read the desired URL as a command-line argument:

func main() { 
    if len(os.Args) != 2 { 
        fmt.Printf("Usage: %s URL\n", filepath.Base(os.Args[0])) 
        return 
    } 
 
    URL := os.Args[1] 

The third code portion of webClient.go is where the real action takes place:

    data, err := http.Get(URL) 
 
    if err != nil { 
        fmt.Println(err) 
        return 

All of the work is done by the http.Get() call...