Replace URL Character Encodings In Windows Filenames (Batch)

Question

I am trying to replace URL encodings (e.g. %20 as a placeholder for a space) with their corresponding ASCII values in all filenames in a Windows folder and its subfolders.

If have a simple .bat file that can accomplish this, but it has limitations:

@echo off
Setlocal enabledelayedexpansion

Set "Pattern0=%%20"
Set "Replace0= "

Set "Pattern1=%%27"
Set "Replace1='"

Set "Pattern2=%%28"
Set "Replace2=("

Set "Pattern3=%%29"
Set "Replace3=)"

Set "Pattern4=%%5B"
Set "Replace4={"

Set "Pattern5=%%5D"
Set "Replace5=}"

For %%# in ("D:\Dropbox\Music\*.mp3") Do (
    Set "File=%%~nx#"
    Ren "%%#" "!File:%Pattern0%=%Replace0%!"
    Ren "%%#" "!File:%Pattern1%=%Replace1%!"
    Ren "%%#" "!File:%Pattern2%=%Replace2%!"
    Ren "%%#" "!File:%Pattern3%=%Replace3%!"
    Ren "%%#" "!File:%Pattern4%=%Replace4%!"
    Ren "%%#" "!File:%Pattern5%=%Replace5%!"
)

Pause&Exit

There are two major limitations I'd like to fix:

1. It only checks the ..\Music\ folder root. I'd like it to look at files in subdirectories, too.
2. It exits the For loop as soon as one of the renames are executed (all %20's replaced first pass, for example, but nothing else).

And surely there is a better way to specify the encodings and their replacements (rather than variable pairs for each), but that's a nice-to-have feature.

These encodings always take the form %XX, where X are hexadecimal values.

Answer 1

1. To solve directory recursive search, you could use dir /s /b instead

FOR /F "delims=" %%# in ('dir /s /b "D:\Dropbox\Music\*.mp3"') Do (
...
)

2. Do not rename the file any time, only after all replacements

FOR /F "delims=" %%# in ('dir /s /b "D:\Dropbox\Music\*.mp3"') Do (
   set "file=%%~#"
   set "file="!File:%%20= !"
   set "file="!File:%%28=(!"
   ...
   move "%%~#" "!file!"
)

I'm using move here, because it works with full pathnames, too

3. To solve problems with exclamation marks in filenames/paths, you need to toggle delayed expansion

setlocal DisableDelayedExpansion
FOR /F "delims=" %%# in ('dir /s /b "D:\Dropbox\Music\*.mp3"') Do (
   set "file=%%~#"

   setlocal EnableDelayedExpansion
   set "file="!File:%%20= !"
   set "file="!File:%%28=(!"
   ...
   move "%%~#" "!file!"
   endlocal
)