Go Systems Programming

Using io.Copy

This subsection will present a technique for copying files that uses the io.Copy() function. What is special about the io.Copy() function is the fact that is does not give you any flexibility in the process. The name of the program will be notGoodCP.go and will be presented in three parts. Note that a more appropriate filename for notGoodCP.go would have been copyEntireFileAtOnce.go or copyByReadingInputFileAllAtOnce.go!

The first part of the Go code of notGoodCP.go is the following:

package main 
 
import ( 
   "fmt" 
   "io" 
   "os" 
) 

The second part is as follows:

func Copy(src, dst string) (int64, error) { sourceFileStat, err := os.Stat(src) if err != nil { return 0, err } if !sourceFileStat.Mode().IsRegular() { return 0, fmt.Errorf("%s ...