// +build OMIT package main import ( "fmt" "io/ioutil" "log" ) func main() { const filename = "/tmp/file.txt" err := ioutil.WriteFile(filename, []byte("Hello, file system\n"), 0644) if err != nil { log.Fatal(err) } b, err := ioutil.ReadFile(filename) if err != nil { log.Fatal(err) } fmt.Printf("%s", b) }