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 (20 chapters)
Title Page

Compiling Go code

In this section, you will learn how to compile Go code. The good news is that you can compile your Go code from the command line without the need for a graphical application. Furthermore, Go does not care about the name of the source file of an autonomous program as long as the package name is main and there is a single main() function in it. This is because the main() function is where the program execution begins. As a result, you cannot have multiple main() functions in the files of a single project.

We will start our first Go program compilation with a program named aSourceFile.go that contains the following Go code:

package main 
import ( 
func main() { 
    fmt.Println("This is a sample Go program!") 

Notice that the Go community prefers to name the Go source file source_file.go instead of aSourceFile.go. Whatever you choose, be consistent.

In order to compile aSourceFile.go and create a statically linked executable file, you will need to execute the following command:

$ go build aSourceFile.go

After that, you will have a new executable file named aSourceFile that you will need to execute:

$ file aSourceFile
aSourceFile: Mach-O 64-bit executable x86_64
$ ls -l aSourceFile
-rwxr-xr-x  1 mtsouk  staff  2007576 Jan 10 21:10 aSourceFile
$ ./aSourceFile
This is a sample Go program!

The main reason why the file size of aSourceFile is that big is because it is statically linked, which means that it does not require any external libraries to run.