Powershell find folders, delete files leaving latest 5 - powershell

Question

We use software called Revit, files are saved as such: filename.rvt
Each time a user edits a file, Revit takes it upon itself to save the old file in the format filename.xxxx.rvt (where xxx is a number).
Over time when files are edited hundreds of times, we have many unnecessary files on the file server.
I am writing a script to:
Locate and folders containing Revit backup files
Delete all but the most recently modified 5 revit backup files
I have tried two approaches below
$searchpath = "e:\"
# Find a unique list of directories that contains a revit backup file (*.*.rvt)
$a = Get-ChildItem -Path $searchpath -Include *.*.rvt -Recurse | Select-object Directory -expandproperty FullName | Get-Unique -AsString
# For each folder that contains a single revit backup file (*.*.rvt)...
# - Sort by modified time
# - Select all except first 5
$a | Get-ChildItem -Include *.*.rvt | Sort-Object LastWriteTime -descending | select-object -skip 5 -property Directory,Name,CreationTime,LastWriteTime | Out-GridView -Title "Old Backups" -PassThru
The issue with this approach is that it only "skips" the first 5 files in the entire search result, not 5 in each folder.
Then I went about it using a loop, and this gets nowhere:
$searchpath = "e:\"
# Find a unique list of directories that contains a revit backup file (*.*.rvt)
$a = Get-ChildItem -Path $searchpath -Include *.*.rvt -Recurse | Select Directory | Get-Unique -AsString
# For each folder that contains a single revit backup file (*.*.rvt)...
# - Sort by modified time
# - Select all except first 5
$a | foreach {
$b += Get-ChildItem -Path $_.Directory.FullName -Include *.*.rvt | Sort-Object LastWriteTime -descending | select-object -skip 5 -property Directory,Name,CreationTime,LastWriteTime
}
$b | Out-GridView -Title "Old Backups" -PassThru
Any thoughts on the correct approach and whats going wrong?

Answer 1

try this:
get-childitem -file -recurse | group Directory | where Count -gt 5 | %{
$_.Group | Sort LastWriteTime -descending | select -skip 5 Directory,Name,CreationTime,LastWriteTime
} | Out-GridView -Title "Old Backups"
If you want delete you can do it (remove what if)
gci -file -recurse | group Directory | where Count -gt 5 | %{
$_.Group | Sort LastWriteTime -descending | select -skip 5 | remove-item -WhatIf
}

Answer 2

The key to do what you seek is to use the Group-Object cmdlet.
In your case, the group you want to create is a group containing all items in the same folder. This will give you something like this:
From there, you can perform actions on each group, such as selecting all the files while skipping the first 5 of each folders and deleting the remaining.
See this simple minimalist example:
$Path = 'C:\__TMP\1'
$Items = Get-ChildItem -Path "$path\*.rvt" -Recurse | Group-Object -Property PsparentPath
Foreach ($ItemsGroup in $Items) {
$SortedFiles = $ItemsGroup.Group | sort LastWriteTime -Descending
$SortedFiles | Select-Object -Skip 5 | % {Write-host "Deleting $($_.FullName)"; Remove-Item $_.FullName}
}

Answer 3

Try something like this:
$searchpath = "E:\"
$number = 5
$directories = Get-ChildItem -Path $searchpath -Include *.*.rvt -Recurse | Where-Object {$_.PsIsContainer}
foreach ($dir in $directories)
{
$files = Get-ChildItem -Path $dir.FullName | Where-Object {-not $_.PsIsContainer}
if ($files.Count -gt $number)
{
$files | Sort-Object CreationTime | Select-Object -First ($files.Count - $number) | Remove-Item -Force
}
}
Change the placeholders accordingly. I just gave you the logical approach.

Answer 4

An alternative solution that doesn't require grouping first and instead processes each directory separately:
& { Get-Item $path; Get-ChildItem -Directory -Recurse $path } | # get all dirs.
ForEach-Object { # for each dir.
Get-ChildItem -File $_.FullName/*.*.rvt | # get backup files in dir.
Sort-Object -Descending LastWriteTime | # sort by last-write time, newest first
Select-Object -Skip 5 | # skip the 5 newest
Remove-Item -Force -WhatIf # delete
}
Note: The -WhatIf common parameter in the command above previews the operation. Remove -WhatIf once you're sure the operation will do what you want.