Golang : Read a file into an array or slice example

Ok, got a junior developer that wants to know how to read a text file content line by line into an array or slice. He is dealing with a legacy software that doesn't send out data either in JSON or XML format. The legacy software output is in text format.

Solution :

Use strings.Split() function with newline (\n) as the separator and ioutil.ReadFile() function.

Here you go!

 package main

 import (
  "fmt"
  "io/ioutil"
  "os"
  "strings"
 )

 func main() {
  if len(os.Args) <= 1 {
 fmt.Printf("USAGE : %s <target_filename> \n", os.Args[0])
 os.Exit(0)
  }

  fileName := os.Args[1]

  fileBytes, err := ioutil.ReadFile(fileName)

  if err != nil {
 fmt.Println(err)
 os.Exit(1)
  }

  sliceData := strings.Split(string(fileBytes), "\n")

  fmt.Println(sliceData)
 }

Reference:

https://golang.org/pkg/strings/#Split