Go Standard Library Cookbook

How to do it...

1. Open the console and create the folder chapter05/recipe03.
2. Navigate to the directory.
3. Create the directory temp and create the file file.txt in it.

4. Edit the file.txt file and write This file content into the file.
5. Create the openfile.go file with the following content:

        package main        import (          "fmt"          "io"          "io/ioutil"          "os"        )        func main() {          f, err := os.Open("temp/file.txt")          if err != nil {            panic(err)          }          c, err := ioutil.ReadAll(f)          if err != nil {            panic(err)          }          fmt.Printf("### File content ###\n%s\n", string(c))          f.Close()          f, err = os.OpenFile("temp/test.txt", os.O_CREATE|os.O_RDWR,                               os.ModePerm)          if err != nil {            panic(err)          }          io.WriteString(f, "Test string")          f.Close()        }

6. The file structure should look like this:

7. Execute the code ...