Golang file renaming - go

Question

Since yesterday I was trying to write a script/program that would change filenames. Alongside learning golang I also started to make animations and for some reason Illustrator names every .png file I make like this - "name_working space 1 copy.png" and "* copy (number).png". I was tired of renaming those files manually and today I found this code and modified 1 line of it to get rid of "_working space 1 copy" but only from those files that have numbers. That leaves me with 2 files that are first frames of my animations and those are - "name_working space 1.png"; "name_working space 1 copy.png". I could totaly live with it by leaving those 2 blank but since I try to learn golang I wanted to ask if I can improve it to replace every single filename. I started learning monday this week.
import (
"fmt"
"log"
"os"
"path/filepath"
"regexp"
)
func currentDir() {
dir := "D:\\GoLang\\src\\gocourse\\renamefile\\rename"
file, err := os.Open(dir)
if err != nil {
log.Fatalf("failed using this directory %s", err)
}
defer file.Close()
list, err := file.Readdirnames(0)
if err != nil {
log.Fatalf("failed reading directory: %s", err)
}
re := regexp.MustCompile("_working space 1 copy ")
for _, name := range list {
oldName := name
fmt.Println("Old name - ", oldName)
newName := re.ReplaceAllString(oldName, "$1")
fmt.Println("New Name - ", newName)
err := os.Rename(filepath.Join(dir, oldName), filepath.Join(dir, newName))
if err != nil {
log.Printf("error renaming file: %s", err)
continue
}
fmt.Println("File names have been changed")
}
}
func main() {
currentDir()
}
ball_working space 1.png --> ball-1.png;
ball_working space 1 copy.png --> ball-2.png;
ball_working space 1 copy 1.png --> ball-3.png;
ball_working space 1 copy 2.png --> ball-4.png etc.

Answer 1

Here is a reimplementation of your code. However it is not complete, as you need
to better clarify what the names look like before, and what they should look like
after.
package main
import (
"os"
"path/filepath"
"strings"
)
func main() {
dir := `D:\GoLang\src\gocourse\renamefile\rename`
list, err := os.ReadDir(dir)
if err != nil {
panic(err)
}
for _, each := range list {
name := each.Name()
newName := strings.ReplaceAll(name, "_working space 1 copy", "")
os.Rename(filepath.Join(dir, name), filepath.Join(dir, newName))
}
}

Answer 2

I guess you could just parse the first part of each file name until it encounters an underscore. A function to illustrate if you are sure that the file you want to extract always ends with the same symbol '_'.
fileNames := []string{"ball_working space 1.png", "ball_working space 1 copy.png",
"ball_working space 1 copy 1.png", "ball_working space 1 copy 2.png"}
func parseName(names []string) {
res := []string{""}
for ind, val := range names {
data := val[:strings.IndexByte(val, '_')] // reads until the hardcoded symbol
data += "-" + strconv.Itoa(ind)
res = append(res, data)
return res
}
Then you will have a slice with all the "correct" file names and you can unpack it in your way of preference.