How do I increment a folder name using Windows batch?

Question

I've got a batch script that creates a folder named New_Folder and a few subdirectories and files within. Currently, if I need to create multiple New_Folders I have to rename each New_Folder created by the batch before I can run it again and create a new one. What I'd like to do is have the batch check and see if New_Folder already exists, and if so, to increment New_Folder by a number. So I'd have New_Folder, New_Folder1, New_Folder2, and so on.

How would I go about doing this? The solutions I've seen for incrementing things in batch scripts don't seem to apply to my situation, and I don't know anything about batch scripting beyond what I've copy/pasted for my own code.

Answer 1

Here is a solution that will always work, even if there are gaps in the numbers. The folder number will always be 1 greater than the current max number.

@echo off
setlocal enableDelayedExpansion
set "baseName=New_Folder"
set "n=0"
for /f "delims=" %%F in (
  '2^>nul dir /b /ad "%baseName%*."^|findstr /xri "%baseName%[0-9]*"'
) do (
  set "name=%%F"
  set "name=!name:*%baseName%=!"
  if !name! gtr !n! set "n=!name!"
)
set /a n+=1
md "%baseName%%n%"