Batch file that keeps the 7 latest files in a folder

Knowledge42 picture Knowledge42 · Nov 13, 2012 · Viewed 19.4k times · Source

Can anyone help me create a batch file? Basically, my goal is to create a batch file that will keep the LATEST 7 .txt files (in other words, the newest) in the folder and subsequently delete the rest. That's IF there are more than 7 files in the folder.

The problem I'm having right now is the fact that the batch file that I have created deletes most of the files because their date is from a month or two or so. I want to keep the latest 7 files at all times no matter how old they are.

So this is what I have -

@echo off

setlocal enableextensions

rem ********************************************************************************
rem *******************************  LOCAL VARIABLES  ******************************
rem ********************************************************************************

SET TargetDirectory="C:\TEMP\test"

SET No_of_fles_to_keep=7

SET count=0 

set cnt=0

rem ********************************************************************************

cd /d %TargetDirectory%

REM timeout /T 500

 for %%x in (*) do set /a count+=1

 for %%A in (*.bat) do set /a cnt+=1

cd /d %TargetDirectory%

REM timeout /T 500

IF %count% gtr %No_of_fles_to_keep% forfiles -p %TargetDirectory% -s -m "*.txt" -d -%No_of_fles_to_keep% -c "cmd /c del @path"

echo %count% 

echo File count = %cnt% 

Any help is appreciated.

Answer

dbenham picture dbenham · Nov 13, 2012

You can use DIR with /O-D to list the text files in descending timestamp order. FOR /F allows you to iterate over each file. SET /A is used to keep track of how many files have been listed so far. Now comes the tricky part.

Within a code block you normally need to use delayed expansion to work with the value of a variable that was set earlier in the same block. But delayed expansion can cause problems in a FOR loop if the FOR variable value contains !, and ! is valid in file names. I get around the problem by using SET /A to intentionally divide by 0 when the 7th file name has been read. This raises an error that causes the conditional code to execute that undefines the KEEP variable. From that point on, all remaining files are deleted.

@echo off
setlocal
set /a cnt=0
set "keep=7"
for /f "eol=: delims=" %%F in ('dir /b /o-d /a-d *.txt') do (
  if defined keep (
    2>nul set /a "cnt+=1, 1/(keep-cnt)" || set "keep="
  ) else del "%%F"
)

Update

Oh my goodness, I just realized there is a trivial solution. Just use the FOR /F SKIP option to ignore the first 7 entries after sorting by last modified date, descending.

for /f "skip=7 eol=: delims=" %%F in ('dir /b /o-d /a-d *.txt') do @del "%%F"

You don't even need a batch file. Just change %% to % if run from the command prompt.