package main import ( "bytes" "fmt" "io/ioutil" "log" "os" ) func main() { path := "main.go" f, err := os.Open(path) if err != nil { log.Fatalf("os.Open() failed with %s\n", err) } defer f.Close() d, err := ioutil.ReadAll(f) if err != nil { log.Fatalf("ioutil.ReadAll() failed with '%s'\n", err) } lines := bytes.Split(d, []byte{'\n'}) fmt.Printf("File %s has %d lines\n", path, len(lines)) }