Equivalent to C#'s “using” keyword in powershell?

Question

When I use another object in the .net-Framework in C# I can save a lot of typing by using the using directive.

using FooCompany.Bar.Qux.Assembly.With.Ridicul         


        

Answer 1

Check out this blog post from a couple years ago: http://blogs.msdn.com/richardb/archive/2007/02/21/add-types-ps1-poor-man-s-using-for-powershell.aspx

Here is add-types.ps1, excerpted from that article:

param(
    [string] $assemblyName = $(throw 'assemblyName is required'),
    [object] $object
)

process {
    if ($_) {
        $object = $_
    }

    if (! $object) {
        throw 'must pass an -object parameter or pipe one in'
    }

    # load the required dll
    $assembly = [System.Reflection.Assembly]::LoadWithPartialName($assemblyName)

    # add each type as a member property
    $assembly.GetTypes() | 
    where {$_.ispublic -and !$_.IsSubclassOf( [Exception] ) -and $_.name -notmatch "event"} | 
    foreach { 
        # avoid error messages in case it already exists
        if (! ($object | get-member $_.name)) {
            add-member noteproperty $_.name $_ -inputobject $object
        }
    }
}

And, to use it:

RICBERG470> $tfs | add-types "Microsoft.TeamFoundation.VersionControl.Client"
RICBERG470> $itemSpec = new-object $tfs.itemspec("$/foo", $tfs.RecursionType::none)

---

Basically what I do is crawl the assembly for nontrivial types, then write a "constructor" that uses Add-Member add them (in a structured way) to the objects I care about.

See also this followup post: http://richardberg.net/blog/?p=38

Answer 2

If you just need to create an instance of your type, you can store the name of the long namespace in a string:

$st = "System.Text"
$sb = New-Object "$st.StringBuilder"

It's not as powerful as the using directive in C#, but at least it's very easy to use.

Answer 3

I realize this is an old post, but I was looking for the same thing and came across this: http://weblogs.asp.net/adweigert/powershell-adding-the-using-statement

Edit: I suppose I should specify that it allows you to use the familiar syntax of...

using ($x = $y) { ... }