CODEWITHSUNDEEP
batch-file
spyky_42
spyky_42

Reputation: 111

Batch file logic to delete files based on date in filename

I now have a seemingly innocuous requirement to be put in a .bat file ,I am dealing with Batch code for the first time ...found a page here that deals with something similar but it takes the modified date as reference.

In a particular folder X , Delete all files older than N days by parsing through their file name. where file name format is Name_YYYYMMDD.log

But note : 1. Do not want the last modified date as reference (log might have been accessed/modified by other programs/apps) 2.No permission to install other utilities.

EDIT :

Thanks!.

Upvotes: 0

Views: 4341

Answers (2)

cmd-fan
cmd-fan

Reputation: 11

here you have, it will delete file e.g. 20180105.log on January 5, it's working with date format YYYY-MM-DD, for date format MM/DD/YYYY change this delims=/ and check "echo todayDate !todayDate!" for manipulating a b c

cls
@echo off
setlocal EnableDelayedExpansion

for /F "tokens=1-3 delims=-" %%a in ("%date%") do (
   set todayDate=%%a%%b%%c
)

rem echo todayDate !todayDate!

for /F "tokens=1-3 delims=_." %%a in ('dir /B /A-D *.*') do (

   set /A daysOld=todayDate - "%%a"

   if !daysOld! EQU 0 (
      echo deleting.. %%a.%%b
      echo del %%a.%%b
   )
)

Test it and change the echo del %%a.%%b to del %%a.%%b

Upvotes: 1

Aacini
Aacini

Reputation: 67216

The Batch file below convert file date to Julian Day Number, that is a sequential number of days, and use it to know how many days old is each one. The number of days to delete files is given in the parameter.

@echo off
setlocal EnableDelayedExpansion

rem Get Julian Day Number of today's date
rem The assumed format is MM/DD/YYYY, change C-A-B order in accordance with your locale
for /F "tokens=1-3 delims=/" %%a in ("%date%") do (
   set todayDate=%%c%%a%%b
)
call :DateToJDN %todayDate% todayJDN=

for /F "tokens=1-3 delims=_." %%a in ('dir /B /A-D *.*') do (
   call :DateToJDN %%b fileJDN=
   set /A daysOld=todayJDN - fileJDN
   if !daysOld! gtr %1 (
      echo File "%%a_%%b.%%c" is !daysOld! days old
   )
)
goto :EOF

:DateToJDN yyyymmdd jdn=
set yyyymmdd=%1
set /A yyyy=%yyyymmdd:~0,4%, mm=1%yyyymmdd:~4,2% %% 100, dd=1%yyyymmdd:~6% %% 100
set /A a=(mm-14)/12, %2=(1461*(yyyy+4800+a))/4+(367*(mm-2-12*a))/12-(3*((yyyy+4900+a)/100))/4+dd-32075
exit /B

Test this program and change the echo File "%%a_%%b.%%c" ... command by the desired del "%%a_%%b.%%c" one.

Reference: http://www.hermetic.ch/cal_stud/jdn.htm#comp

Upvotes: 6

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