Go Golang flatten directory -> read a directory of directories and extract files to another directory

flatten_dir.go

package main

import (
	"path/filepath"
	"os"
	"fmt"
)

const target_directory = "C:\\Users\\WHO?\\Documents\\target\\"
const destination_directory = "C:\\Users\\WHO?\\flatten\\"

func main() {

	//verify if both directories exist
	info, err := os.Stat(target_directory)
	if err != nil {
		panic(err)
	}
	if !info.IsDir() {
		panic("target_directory could not be found...")
	}

	info, err = os.Stat(destination_directory)
	if err != nil {
		panic(err)
	}
	if !info.IsDir() {
		panic("destination_directory could not be found...")
	}

	fileList := make([]string, 0)
	err = filepath.Walk(target_directory, func(path string, f os.FileInfo, err error) error {
		fileList = append(fileList, path)
		return err
	})
	if err != nil {
		panic(err)
	}

	for _, file := range fileList {

		fi, err := os.Stat(file)
		if err != nil {
			fmt.Println(err)
		}

		//only if it's a normal file
		if fi.Mode().IsRegular() {
			err = os.Rename(file, destination_directory+filepath.Base(file))
			if err != nil {
				fmt.Println(err)
			}
		}
	}

}