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)

The first version of find(1)

The Go code in this section is saved as find.go and will be presented in three parts. As you will see, find.go uses a large amount of the code found in traverse.go, which is the main benefit you get when you are developing a program step by step.

The first part of find.go is the expected preamble:

package main 
 
import ( 
   "flag" 
   "fmt" 
   "os" 
   "path/filepath" 
) 

As we already know that we will improve find.go in the near future, the flag package is used here even if this is the first version of find.go and it does not have any flags!

The second part of the Go code contains the implementation of the walkFunction():

func walkFunction(path string, info os.FileInfo, err error) error { 
 
   fileInfo, err := os.Stat(path) 
   if err != nil { 
         return err 
   } 
 
   mode := fileInfo.Mode() 
 ...