Find oldest file and delete

General
1

I am looking to improve an application that writes log files to a particular location. I have a method that looks for the files in a folder and then uses several loops to find the oldest file and delete it.

This is an old method I wrote years ago and I am looking at improving how I find the oldest and then delete it to reduce the time this takes. I could have thousand or so files of at least 2Mb to 12 Mb in size.

Any suggestions on how to proceed and improve?

Thanks

2 
dim oldest as FolderItem = nil
for each f as FolderItem in myFolder.Children
    if not f.IsFolder and f.Name.EndsWith(".log") then
        if oldest = nil or f.ModificationDate < oldest.ModificationDate then oldest = f
    end if
next

if oldest <> nil then oldest.Delete

(untested)

1 Like
3

On windows you might kill off files older than days with a single shell command
I found this:

ForFiles /p “C:\My Folder” /s /d -30 /c “cmd /c del @file”

Substitute the folder path and the amount of days with desired values and you are done.

4

What platform(s)?

5

Thanks to everyone who provided suggestions

Platform is OSX using Big Sur XOJO 2021 r1. I have been updating to get daemons to run on the new XOJO RAD looking to reduce CPU % and memory. Originally I had a memory leak because I used the old way of calling using MyApplication with no Super having Initialize, Idle, Final for Methods. I finally fixed that and started looking at other improvements.

@Paul_Rodman After your post I took a look at my previous method that did this work. I have another area that was similar. So I made a few modifications and used that routine there as well. This works on several terminal apps that act as a daemon all working together using inter processor communications.

That suggestion really helped and I have implemented in all solutions.

Here is a bit of what I used in a final version.

If Current_Log_file.Count >= 500 Then
  
  Var oldest As FolderItem = Nil
  For Each f in Current_Log_file.Children
    If not f.IsFolder and f.Name.EndsWith(".log", ComparisonOptions.CaseSensitive, Locale.Current) Then
      If oldest = nil or f.ModificationDate < oldest.ModificationDate Then oldest = f
    End If
  Next
  
  Var this_file_was_deleted As String = oldest.Name
  Try
    If oldest <> Nil Then oldest.Delete
     // Post File was deleted to Running_Log
    Catch e As IOException
     // Post error to Error_Log
  End

End If
6

Nice code, but you’re accessing oldest.ModificationDate whenever you come across another log file; what if “oldest” disappears or otherwise gets modified while your loop executes?
I’d suggest you use a variable to hold the date.