Go Systems Programming

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 ...