Copy from Specific Folder with Multiple Folders - powershell

Question

I am creating a backup and restore tool with powershell script and I am trying to make it so that when restoring, the script picks the last folder created and restores from that directory structure. Basically I am having the script start with making a backup directory with a date/time stamp like so:
$CurrentUser = [System.Security.Principal.WindowsIdentity]::GetCurrent().Name
$CurrentDomainName = $CurrentUser.split("\")[0]
$CurrentUserName = $CurrentUser.split("\")[1]
$folderdate = Get-Date -f MMddyyyy_Hm
$homedir = Get-Aduser $CurrentUserName -prop HomeDirectory | select -ExpandProperty
HomeDirectory
New-Item $homedir -Name "TXBackup\$folderdate" -ItemType Directory
$cbookmarks = "$env:userprofile\Appdata\Local\Google\Chrome\User Data\Default\Bookmarks"
md $homedir\TXBackup\$folderdate\Chrome
Copy-Item $cbookmarks "$homedir\TXBackup\$folderdate\Chrome" -Recurse
Backup Folder Structure
Basically everytime someone runs the backup tool it will create a subfolder under the Backup directory with the date/time name to track the latest one. The problem comes when I want to restore from the last one create I can no longer use a $folderdate variable since it will pull the whatever the time is while the tool is being run. Here is the code without taking into account what the last folder is. I tried using sort but that doesn't appear to give me a clear path to select the last one created or I just am such a noob I didn't use it right :(
##Restoring Files from Backup
$CurrentUser = [System.Security.Principal.WindowsIdentity]::GetCurrent().Name
$CurrentDomainName = $CurrentUser.split("\")[0]
$CurrentUserName = $CurrentUser.split("\")[1]
$homedir = get-aduser $CurrentUserName -prop HomeDirectory | select -ExpandProperty HomeDirectory
##Restoring Chrome Bookmarks
Sort-Object -Property LastWriteTime |
Select-Object -Last 1
$rbookmarks = "$homedir\TXBackup\$folderdate\Chrome\Bookmarks"
Copy-Item $rbookmarks "C:\Test\"
I know I didn't use that correctly but any direction would be awesome for this newbie :)

Answer 1

You can use Sort-Object with a script block and use [DateTime] methods to parse the date from the folder name, using the same format string you used to create them.
# Sort directory names descending
Get-ChildItem -Directory | Sort-Object -Desc {
# Try to parse the long format first
$dt = [DateTime]::new( 0 )
if( [DateTime]::TryParseExact( $_.Name, 'MMddyyyy_HHmm', [CultureInfo]::InvariantCulture, [Globalization.DateTimeStyles]::none, [ref] $dt ) ) {
return $dt
}
# Fallback to short format
[DateTime]::ParseExact( $_.Name, 'MMddyyyy', [CultureInfo]::InvariantCulture )
} | Select-Object -First 1 | ForEach-Object Name
Note: I've changed the time format from Hm to HHmm, because Hm would cause a parsing ambiguity, e. g. 01:46 would be formatted as 146, but parsed as 14:06.
Also I would move the year to the beginning, e. g. 20220821_1406, so you could simply sort by name, without having to use a script block. But that is not a problem, just an (in)convenience and you might have a reason to put the year after the day.
Given these folders:
08212022
08222022
08222022_1406
08222022_1322
08222022_1324
08222022_1325
08222022_1343
The code above produces the following output:
08222022_1406
To confirm the ordering is correct, I've removed the Select-Object call:
08222022_1406
08222022_1343
08222022_1325
08222022_1324
08222022_1322
08222022
08212022
Note that the ordering is descending (-Desc), so Select-Object -First 1 can be used to more effectively select the latest folder.