Batch Script to Delete Files with Unique Root Stem in Directory - batch-file

Question

Is it possible to write a batch file that deletes all files in a directory for which the first n characters of the file's root name do not match the first n characters of any other filenames in that directory? For instance, suppose the directory contains the following:
Purcell_HenryA.txt
Purcell_HenryB.txt
Casaubon_IsaacA.txt
In this case, we would want to delete all files in the directory whose first 13 characters did not match the first 13 characters in any other files in the directory. (That is, we'd want to delete only Casaubon_IsaacA.txt.) I have tracked down scripts that delete all files with unique extensions in a directory, but don't know how to begin to write this script, and would therefore be grateful for any leads on the question.

Answer 1

This checks for root filenames of 14 characters and over - and if there is only 1 file with the same leading 13 characters then it will echo del. Remove the echo to make it perform the deletion.
#echo off
setlocal enabledelayedexpansion
for /f "delims=" %%a in ('dir /b /a-d') do (
set "part=%%~na"
if not "!part:~13,1!"=="" (
set "part=!part:~0,13!"
for /f "delims=" %%b in ('dir /b /a-d "!part!*.*" ^|find /c "!part!" ') do (
if %%b EQU 1 echo del "%%a"
)
)
)

Answer 2

#ECHO OFF
SETLOCAL ENABLEDELAYEDEXPANSION
SET target=u:\testdir
DIR /b /a-d %target%
echo====^^ names IN DIR ^^===
SET length=13
SET match=:
SET "candidate="
FOR /f "delims=" %%i IN ('dir /b/a-d "%target%\*"') DO (
SET filename=%%i
SET section=!filename:~0,%length%!
IF !section!==!match! (SET "candidate=") ELSE (
IF DEFINED candidate ECHO(DEL %target%\!candidate!
SET candidate=%%i
SET match=!section!
)
)
IF DEFINED candidate ECHO(DEL %target%\!candidate!
GOTO :EOF
Test result:
abc123_uniquename.txt
another_uniquename.txt
duplicate_name1234.txt
duplicate_name1235.txt
duplicate_name1236.txt
hello.txt
repeated__name1236.txt
repeated__name1235.txt
unique__name1235.txt
===^ names IN DIR ^===
DEL u:\testdir\abc123_uniquename.txt
DEL u:\testdir\another_uniquename.txt
DEL u:\testdir\hello.txt
DEL u:\testdir\unique__name1235.txt
If you are happy after testing, remove both ECHO( to activate the delete function.

Answer 3

For this code file name = name+extension:
#echo off &SETLOCAL enabledelayedexpansion
FOR %%a IN (*) DO (
SET "search=%%~a"
IF "!search:~13!" neq "" (
FOR /f "delims=[]" %%b IN ('dir /b /a-d /on "!search:~0,13!*" ^| find /n "!search:~0,13!"') DO SET found=%%b
IF !found! equ 1 ECHO DEL "%%~a"
)
)
And because I coose a very similar solution as foxidrive here is another one:
#echo off &SETLOCAL enabledelayedexpansion
FOR %%a IN (*) DO (
SET search=%%a
IF "!search:~13!" neq "" SET /a $!search:~0,13!+=1 2>nul
)
FOR /f "tokens=1*delims=$=" %%a IN ('set "$"') DO if %%b equ 1 echo del "%%~a*"

Answer 4

The way i'd go about this is as follows, i will explain the logic and i'll leave you to do the coding.
You will parse all the file names into variables, while increasing each time.
Then you will set a limit to the number of loops to go through. Then you will search the first 13 characters of the file name and if the number of lines is equal to 1 then delete it. After you will increase the variable by 1 and go through the loop, at the end of each loop it will check if it has reached the limit aka the number of files in the directory, if it has reached the limit, end the loop, otherwise continue.
hah, i finally decided to do it after a guy decided to use my idea i described into actual code, anyway this is way shorter and a lot faster than his, tested+verified to work:
#echo off & setlocal enabledelayedexpansion
set dir=directoryyouwanttosearchin
for /f "delims=" %%a in ('dir /A:a /b %dir%') do set /A name+=1 & set file!name!=%%a
:LOOP
set /A cnt+=1
for /f "delims=" %%a in ('dir /A:a /b %dir% ^| find /C /I "!file%cnt%:~0,13!"') do set lines=%%a
if %lines%==1 del %dir%\!file%cnt%! > nul
if %cnt% NEQ %name% Goto :LOOP
exit /b
That's 9 lines :).