Go Systems Programming

Reading a file all at once!

The technique in this section will use the ioutil.WriteFile() and ioutil.ReadFile() functions. Note that ioutil.ReadFile() does not implement the io.Reader interface and therefore is a little restrictive.

The Go code for this section is named readAll.go and will be presented in three parts.

The first part has the following Go code:

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

The second part is the following:

func main() { 
   if len(os.Args) != 3 { 
         fmt.Println("Please provide two command line arguments!") 
         os.Exit(1) 
   } 
 
   sourceFile := os.Args[1] 
   destinationFile := os.Args[2] 

The last part is as follows:

 input, err := ioutil.ReadFile(sourceFile) if err != nil { fmt.Println(err) os.Exit(1) } err = ioutil.WriteFile(destinationFile, ...