How to delete only text files except few files - batch-file

Question

In a certain path I have some different kinds of file type. Eg., .txt, .bas, .cls, etc.
I need to delete only the text files in that path except few files.
For eg, if the path has a.txt, b.txt, c.txt, aa.bas, bb.cls, it should delete only a.txt. It should not delete b.txt and c.txt (Also it should not delete the other extension files).

Answer 1

To delete all ?.txt files in the root folder, excluding b.txt and c.txt
#echo off
for %%i in (?.txt) do (
if not "%%~nxi"=="c.txt" if not "%%~nxi"=="b.txt" echo del "%%i"
)
To do this in the root and subdirectories:
#echo off
for /R %%i in (?.txt) do (
if not "%%~nxi"=="c.txt" if not "%%~nxi"=="b.txt" echo del "%%i"
)
If the files are to be all *.txt files and not just single digit as per your example (add /R to recurse:
#echo off
for %%i in (*.txt) do (
if not "%%~nxi"=="c.txt" if not "%%~nxi"=="b.txt" echo del "%%i"
)
Similarly, but using findstr to only exclude:
#echo off
for /f %%i in ('dir /b /a-d ^|findstr /vi "b.txt" ^|findstr /vi "c.txt"') do (
echo del "%%i"
)
and to search only include:
#echo off
for /f %%i in ('dir /b /a-d ^|findstr /i "a.txt"') do (
echo del "%%i"
)
and to include and search subdirectories:
#echo off
for /f %%i in ('dir /b /s /a-d ^|findstr /i "a.txt"') do (
echo del "%%i"
)
On all of the above examples, remove echo to actually perform the delete, echo is used as a safety measure and will only display the del result to console.
Edit
Seeing as you specifically have a list of files (as per one of you comments) to exclude, you can use something like this. You have to create a file called exclusion.txt and add the files to exclude in list form:
b.txt
c.txt
file with space.txt
d.txt
Then create the batch file and add the code below. When ran, it will prompt for the file extention to filter on, where you can type an extension. i.e txt or simply press enter to perform a delete on all files, except the excluded ones. Just to be safe, I added an additional for loop to simply echo the files and prompt you if you are sure you want to delete the files.
#echo off
set cnt=0 & set excl= & set ext=
echo(
if not exist exclusion.txt echo You have not created an "exclusion.txt" file. & echo( & echo You need to create it first, then rerun the script & echo( & pause & goto :eof
echo Ensure you have listed all files to be excluded in "exclusion.txt" file
echo(
set /p "ext=Add File extention to search on (txt, pdf, etc), or press enter for all files: "
if not defined ext goto cont
if not "%ext:~0,1%"=="." set "ext=.%ext%"
set "ext=*%ext%"
:cont
setlocal enabledelayedexpansion
for /f "delims=" %%a in (exclusion.txt) do (
set /a cnt+=1
set "nlr!cnt!=%%a"
)
for /l %%i in (1,1,%cnt%) do (
if not defined excl (
set "excl=!nlr%%i!"
) else (
set "excl=!excl! !nlr%%i!"
)
)
echo(
echo WARNING: You are about to delete the following files!!
echo(
for /f "delims=" %%i in ('dir /b /a-d %ext% ^|findstr /VIE "%excl%"') do (
if /i not "%%i"=="exclusion.txt" if not "%%i"=="%~0" echo %%i
)
echo(
Choice /c YN /m "Are you sure you want to delete these files?"
if %errorlevel% equ 2 goto :eof
for /f "delims=" %%i in ('dir /b /a-d %ext% ^|findstr /VIE "%excl%"') do (
if /i not "%%i"=="exclusion.txt" if not "%%i"=="%~0" del %%i
)