Book Image

Go Systems Programming

Book Image

Go Systems Programming

Overview of this book

Go is the new systems programming language for Linux and Unix systems. It is also the language in which some of the most prominent cloud-level systems have been written, such as Docker. Where C programmers used to rule, Go programmers are in demand to write highly optimized systems programming code. Created by some of the original designers of C and Unix, Go expands the systems programmers toolkit and adds a mature, clear programming language. Traditional system applications become easier to write since pointers are not relevant and garbage collection has taken away the most problematic area for low-level systems code: memory management. This book opens up the world of high-performance Unix system applications to the beginning Go programmer. It does not get stuck on single systems or even system types, but tries to expand the original teachings from Unix system level programming to all types of servers, the cloud, and the web.
Table of Contents (13 chapters)

A simplified Go version of the dd utility

The dd(1) tool can do many things, but this section will implement a small part of its functionality. Our version of dd(1) will include support for two command-line flags: one for specifying the block size in bytes (-bs) and the other for specifying the total number of blocks that will be written (-count). Multiplying these two values will give you the size of the generated file in bytes.

The Go code is saved as ddGo.go and will be presented to you in four parts. The first part is the expected preamble:

package main 
 
import ( 
   "flag" 
   "fmt" 
   "math/rand" 
   "os" 
   "time" 
) 

The second part contains the Go code of two functions:

func random(min, max int) int { 
   return rand.Intn(max-min) + min 
} 
 
func createBytes(buf *[]byte, count int) { 
   if count == 0 { 
        ...