Question : batch rename

MS-DOS - Batch programming
I have several subdirs with an undefined number of jpeg files in them which I want to rename with a dos batch job.
the filenames of the jpeg files are all irregular before the batch job and should be renamed to 001.jpg, 002.jpg, etc.

Here again what I am looking for in other words: the batch routine I am looking for should enter all existing subdirs count the number of existing jpeg files there and rename them into 000.jpeg to max.number.jpeg

Thanks for your help/ idea

Answer : batch rename

Try this:

@echo off

setlocal

REM ** To activate code, change the line to: set debug=
set debug=echo

set rootDir=.
set fileMask=*.jpg

if not "%~1"=="" set rootDir=

if not exist "%rootDir%" echo "%rootDir% root directory does not exist.&goto :EOF

pushd "%rootDir%"

for /f "tokens=*" %%a in ('dir /ad /s /b 2^>NUL') do call :PROCDIR "%%a"

popd

goto :EOF

:PROCDIR

set nextSeq=1

pushd "%~1"

for /f "tokens=*" %%a in ('dir /a-d /b "%fileMask%" 2^>NUL') do %debug% ren "%%a" "_%%a"
for /f "tokens=*" %%a in ('dir /a-d /b "%fileMask%" 2^>NUL') do call :PROCFILE "%%a"

popd

goto :EOF

:PROCFILE

set /a nextFile=1000 + %nextSeq%

%debug% ren "%~1" "%nextFile:~1%%~x1"

set /a nextSeq+=1

goto :EOF