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

File permissions

A popular topic in UNIX systems programming is UNIX file permissions. In this section, you will learn how to print the permissions of any file, provided that you have the required UNIX permission to do so. The name of the program is permissions.go, and it will be presented in three parts.

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

package main 
import ( 

The second code segment of permissions.go is shown in the following Go code:

func main() { 
    arguments := os.Args 
    if len(arguments) == 1 { 
        fmt.Printf("usage: permissions filename\n") 

The last part of this utility follows:

    filename := arguments[1] 
    info, _ := os.Stat(filename) 
    mode := info.Mode() 
    fmt.Println(filename, "mode is", mode.String()[1:10]) 

The call to os...