Rename files depending on parent and grand-parent folder names - windows

Question

I need windows batch file to prefix filename in subfolders with name of folder & subfolder name
e.g. I have folder created for date 12012017 with following structure
d:\12012017\1234\ABC\file1.txt
d:\12012017\1234\ABC\file2.txt
d:\12012017\5678\PQR\file3.txt
d:\12012017\2345\XYZ\file4.txt
Need them to rename to
d:\12012017\1234\ABC\1234_ABC_file1.txt
d:\12012017\1234\ABC\1234_ABC_file2.txt
d:\12012017\5678\PQR\5678_PQR_file3.txt
d:\12012017\2345\XYZ\2345_XYZ_file4.txt
Tried following code but didn't work
set mydate=%date:~0,2%%date:~3,2%%date:~6,4%
REM ECHO %mydate%
D:
CD D:\%mydate%
#ECHO STARTING RENAME
pushd D:\%mydate%
for /d %%D in (*) do (
#ECHO 1- pushd "%%D"
#ECHO CD %%D
for /d %%X in (*) do (
#ECHO pushd "%%X"
for /r %%F in (*) do (
#ECHO 2- pushd "%%F"
for %%P in ("%%F\..") do (
#ECHO 3- pushd "%%P"
#ECHO 4 - ren "%%F" "%%~nxD_%%~nxF"
)
)
)
popd
)
popd
CD\

Answer 1

There are better ways to get the current date in the correct format, but I will preserve your existing method that is locale dependent.
It is important to use FOR /F with DIR on the inner loop instead of simple FOR because simple FOR can iterate files that have been already named, but FOR /F will not.
#echo off
:: Set current directory to today's date
pushd "d:\%date:~0,2%%date:~3,2%%date:~6,4%"
for /d %%A in (*) do ( %= Iterate all child folders =%
for /d %%B in ("%%A\*") do ( %= Iterate grandchild folders = %
for /f "eol=: delims=" %%F in ( %= Iterate result of DIR command =%
'dir /b /a-d "%%~B\*" 2^>nul' %= List all files in grandchild folder =%
) do ren "%%~B\%%F" "%%~A_%%~nxB_%%F" %= Rename each file =%
)
)
popd