New OlderThan and NewerThan parameters for Get-ChildItem cmdlet

Summary of the new feature/enhancement

Today, to find elements of the file system older than (or newer than) the specified date, we are forced to do something like

$Path = "C:\temp"
$Daysback = "-30"
 
$CurrentDate = Get-Date
$DateOlderThan = $CurrentDate.AddDays($Daysback)
Get-ChildItem $Path -Recurse ( | Where-Object { $_.LastWriteTime -lt $DateOlderThan }

At the same time, Test-Path cmdlet supports the parameters -OlderThan <datetime> and -NewerThan <datetime>

Proposal

Add -OlderThan <datetime> and -NewerThan <datetime> parameters to Get-ChildItem cmdlet of the FileSystem provider.

As result we get more short form and more fast and efficient filtering without extra file object retrieving and piping.

$Path = "C:\temp"
$Daysback = "-30"
 
$CurrentDate = Get-Date
$DateOlderThan = $CurrentDate.AddDays($Daysback)
Get-ChildItem $Path -Recurse -OlderThan $DateOlderThan

Proposed technical implementation details (optional)

Example of the parameters definition https://github.com/PowerShell/PowerShell/blob/281b437a65360ae869d40f3766a1f2bbba786e5e/src/System.Management.Automation/namespaces/FileSystemProvider.cs#L7805

Place for new parameters https://github.com/PowerShell/PowerShell/blob/281b437a65360ae869d40f3766a1f2bbba786e5e/src/System.Management.Automation/namespaces/FileSystemProvider.cs#L7531

Place for injection new filtering code (for Recurse parameter) https://github.com/PowerShell/PowerShell/blob/281b437a65360ae869d40f3766a1f2bbba786e5e/src/System.Management.Automation/namespaces/FileSystemProvider.cs#L1779

[thecliguy]

A switch parameter sounds fine.

Regarding the parameter names -OlderThan and -NewerThan, they are somewhat ambiguous… It’s not totally obvious whether a comparison is performed against LastWriteTime or CreationTime.

The documentation of these parameters in relation to Test-Path is currently very poor:

-NewerThan

Specify a time as a DateTime object.

-OlderThan

Specify a time as a DateTime object.

So whatever the final implementation of these new parameters is, it would be great if there’s some meaningful documentation to accompany them.

[iRon7]

You might also consider to accept (besides a DateTime type) a TimeSpan type:

$Path = 'C:\temp'
$Daysback = New-TimeSpan -Days -30

Get-ChildItem $Path -Recurse -OlderThan $Daysback