Golang : Text file editor (accept input from screen and save to file)

The images of me learning WordStar as kid somehow appeared in my dream yesterday. So, today I'm going to write this tutorial to mimic a simple text editor and also to demonstrate how to accept input from screen and save each input line directory into a file.

The code below will accept text input from each line and save it to a text file. To exit the program and save the file, you need to go to a new line and enter a dot/period ( . )

scrinputtofile.go

 package main

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

 func main() {
 fname := "data.txt"

 // print text file
 textin, err := ioutil.ReadFile(fname)
 if err == nil {
 fmt.Println(string(textin))
 }

 var userInput []string

 scanner := bufio.NewScanner(os.Stdin)

 for scanner.Scan() {
 line := scanner.Text()
 if line == "." {
 break // to stop writing enter . (period) and press enter
 }
 userInput = append(userInput, line+"\n")
 }

 // append text to file
 // 0666 means everyone can read and write but not execute

 f, err := os.OpenFile(fname, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0666)
 defer f.Close()

 if err == nil {
 fmt.Println("Saving to file and exit program")
 for _, eachLine := range userInput {
 io.WriteString(f, eachLine)
 }
 }

 // print text file
 textin, err = ioutil.ReadFile(fname)
 if err != nil {
 panic(err)
 }
 fmt.Printf("%s content : \n ", fname)
 fmt.Println(string(textin))
 }

Sample output :

./scrinputtofile

 this is line 1
 this is line 2
 this is line 3
 this is line 4
 this is line 5
 this is line 6
 你好吗(how are you) ?
 .

Saving to file

text.txt content :

this is line 1

this is line 2

this is line 3

this is line 4

this is line 5

this is line 6

你好吗(how are you) ?