Creating, reading and writing a file in Golang

main.go

package main

import (
	"io"
	"log"
	"os"
)

func main() {
	file, err := os.OpenFile("text.txt",
		os.O_RDWR|os.O_CREATE,
		0666,
	)

	if err != nil {
		log.Fatalf("Error openFile: %v", err)
	}
	defer file.Close()

	readByteSlice := make([]byte, 16)
	bytesRead, err := file.Read(readByteSlice)
	if err != nil && err != io.EOF {
		log.Fatalf("Error reading file: %v", err)
	}
	log.Printf("Number of bytes read: %d\n", bytesRead)
	log.Printf("Data read: %s\n", readByteSlice)

	byteSlice := []byte("Bytes!\n")
	bytesWritten, err := file.Write(byteSlice)
	if err != nil {
		log.Fatalf("Error writting file: %v", err)
	}
	log.Printf("Wrote %d bytes. \n", bytesWritten)
}