Recursive "touch" on fileserver - windows

Question

There's something I want to accomplish with administrating my Windows file server:
I want to change the "Last Modified" date of all the folders on my server (just the folders and subfolders, not the files within them) to be the same as the most recent "Created" (or maybe "Last Modified") date file within the folder. (In many cases, the date on the folder is MUCH newer than the newest file within it.)
I'd like to do this recursively, from the deepest subfolder to the root. I'd also like to do this without me manually entering any dates and times.
I'm sure with a combination of scripting and a Windows port of "touch" I could maybe accomplish this. Do you have any suggestions? I could maybe accomplish this. Do you have any suggestions?
This closed topic seems really close but I'm not sure how to only touch folders without touching the files inside, or how to get the most-recent-file's date. Recursive touch to fix syncing between computers

Answer 1

If it's for backup purposes, in Windows there is the Archive flag (instead of modifying the timestamp). You can set it recursively with ATTRIB /S (see ATTRIB /?)
If it is for other purposes you can use some touch.exe implementation and use a recursive for:
FOR /R (see FOR /?)
http://ss64.com/nt/for_r.html
http://ss64.com/nt/touch.html

Answer 2

I think that you can do this in PowerShell. I just tried throwing something together and it seems to work correctly. You could invoke this in PowerShell using Set-DirectoryMaxTime(".\Directory") and it will operate recursively on each directory under that.
function Set-DirectoryMaxTime([System.IO.DirectoryInfo]$directory)
{
# Grab a list of all the files in the directory
$files = Get-ChildItem -File $directory
# Get the current CreationTime of the directory we are looking at
$maxdate = Get-Date $directory.CreationTime
# Find the most recently edited file's LastWriteTime
foreach($file in $files)
{
if($file.LastWriteTime -gt $maxdate) { $maxdate = $file.LastWriteTime }
}
# This needs to be in a try/catch block because there is a reasonable chance of it failing
# if a folder is currently in use
try
{
# Give the directory a LastWriteTime equal to the newest file's LastWriteTime
$directory.LastWriteTime = $maxdate
} catch {
# One of the directories could not be updated
Write-Host "Could not update directory: $directory"
}
# Get all the subdirectories of this directory
$subdirectories = Get-ChildItem -Directory $directory
# Jump into each of the subdirectories and do the same thing to each of their CreationTimes
foreach($subdirectory in $subdirectories)
{
Set-DirectoryMaxTime($subdirectory)
}
}