Select-Object - Keep default columns but add one - powershell

Question

I can use Select-Object to choose which columns to show and even add calculated columns. An example:
gci | select *, #{n='LAS'; e={(Get-Date)-$_.LastAccessTime}}
I want add a calculated column but keep the defaut ones. Without the * wildcard I only get my calculated property. With it I get everything. The only workaround I've got to work is to manually list the default property names. Any ideas?

Answer 1

The thing is that that you actually states to display all properties ('*').
So to add to only the standard properties, you first need to get the standard properties.
[string[]]$StdProperties = (Get-ChildItem).PSStandardMembers.DefaultDisplayPropertySet[1].ReferencedPropertyNames
We don't actually want to change the standard property of the objects returned
Get-Childitem | select Name | Get-Member| group TypeName | select Name
Name
----
Selected.System.IO.DirectoryInfo
Selected.System.IO.FileInfo
So we just need to expand on that extracted string array with the new property to use.
$StdProperties += 'LAS'
And finally, to put it to use...
Get-ChildItem | select *, #{n='LAS'; e={(Get-Date) - $_.LastAccessTime}} |
select $StdProperties

Answer 2

Just for fun, building on Abrahams comment, you could do something weird like this:
# get the default properties used on Format-Table
$defaultProps = (((Get-ChildItem | Format-Table | Out-String) -split '\r?\n' |
Where-Object { $_ -match '^\w.*' }) |
Select-Object -First 1) -split '\s+' -ne ''
# now execute the command
Get-ChildItem | Select-Object *, #{n='LAS'; e={(Get-Date)-$_.LastAccessTime}} |
Select-Object ($defaultProps + 'LAS') | Format-Table -AutoSize