Golang : Convert file content into array of bytes

It is a fairly common requirement to read a file content into array of bytes and output those arrays back to a file. In this tutorial, we will explore how to convert file content into array of bytes in Go.

See the example code below :

readfileintobytes.go

 package main

 import (
 "fmt"
 "io"
 "os"
 "bufio"
 "bytes"
 )

 func main () {
 file, err := os.Open("testdata.txt")

 if err != nil {
 panic(err.Error())
 }

 defer file.Close()

 reader := bufio.NewReader(file)
 buffer := bytes.NewBuffer(make([] byte,0))


 var chunk []byte
 var eol bool
 var str_array []string

 for {
 if chunk, eol, err = reader.ReadLine(); err != nil {
 break
 }
 buffer.Write(chunk)
 if !eol {
 str_array = append(str_array, buffer.String())
 buffer.Reset()
 }
 }

 if err == io.EOF {
 err = nil
 }

 fmt.Println(str_array) // you can redirect the str_array content to a file here instead of println
 }

Reference :

How to generate checksum for file in Go

StackOverFlow

http://golang.org/pkg/bufio/#Reader.ReadLine