go read and write file; IO file

file_helper.go

package main

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

func check(e error, s string) {
	if e != nil {
		log.Fatal(s)
	}
}

func read(filename string) string {
	file, err := os.Open(filename)
	check(err, fmt.Sprintf("cannot open %v", filename))
	content, err := ioutil.ReadAll(file)
	check(err, fmt.Sprintf("cannot read %v", filename))
	defer func() {
		if err = file.Close(); err != nil {
			log.Fatal(err)
		}
	}()
	return string(content)
}

func write(filename string, content string) {
	f, err := os.Create(filename)
	check(err, fmt.Sprintf("cannot create %v", filename))
	_, err = f.WriteString(content)
	check(err, fmt.Sprintf("cannot write %v", filename))
	defer func() {
		if err = f.Close(); err != nil {
			log.Fatal(err)
		}
	}()
}