PowerShell: Select custom expression and expand in one operation - powershell

Question

I can do something like
ls . `
| select #{ Name="Dir"; Expression = { $_ | Split-Path } } `
| select -ExpandProperty Dir
to select a custom expression (in this case $_ | Split-Path) into a simple array of values.
Is there a way to merge the two select statements into one, that still yields equivalent results?

Answer 1

I think the OP is looking for ForEach-Object (MSDN), which performs an operation against each item in a collection of input objects. It's similar to the map or Select operation in other languages.
So instead of:
ls . `
| select #{ Name="Dir"; Expression = { $_ | Split-Path } } `
| select -ExpandProperty Dir
You want:
ls . `
| ForEach-Object { $_ | Split-Path }
You can also replace ForEach-Object with %. But it's less readable and less searchable for new PowerShell users:
ls . `
| % { $_ | Split-Path }

Answer 2

What are you trying to do? You could get the same results with just ls/Get-ChildItem and Split-Path. Not sure if you need the Microsoft.PowerShell.Core\FileSystem:: part.
PS C:\Path\To\Dir> Get-ChildItem | Split-Path
Microsoft.PowerShell.Core\FileSystem::C:\Path\To\Dir
Microsoft.PowerShell.Core\FileSystem::C:\Path\To\Dir
Microsoft.PowerShell.Core\FileSystem::C:\Path\To\Dir
PS C:\Path\To\Dir> (Get-ChildItem).FullName | Split-Path
C:\Path\To\Dir
C:\Path\To\Dir
C:\Path\To\Dir
Edit
Assuming nuget list <my-package> outputs a string array, you can use -replace and regex ($ to match string end) to manipulate it and get an array of results.
$((nuget list <my-package>).Replace(" ",",") -replace "$",".nupkg")