today.go

package main

import (
	"fmt"
	homedir "github.com/mitchellh/go-homedir"
	"os"
	"time"
)

func main() {
	dir, _ := homedir.Dir()
	path := dir + "/,/" + time.Now().Format("20060102") + ".md"

	// check file
	_, exists_err := os.Stat(path)
	if !os.IsNotExist(exists_err) {
		fmt.Println("already created file is : " + path)
		os.Exit(1)
	}

	// create file
	if _, err := os.Create(path); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	fmt.Println(path)
}