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

  See also : Golang : Display a text file line by line with line number example





By Adam Ng(黃武俊)

IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.


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