Richard Siddaway's Blog

As an alternative to the –contains operator you can use the –in operator

Repeating the tests from the previous post on –contains

PS> $primes = 1,3,5,7,11,13,17,19,23,29,31,37,41,43,47
PS> $candidate = 7
PS> $candidate -in $primes
True

PS> $candidate = 4
PS> $candidate -in $primes
False

The –in operator can be used in the simplified where syntax but –contains can’t

Sometimes you may want to test if a value is in a collection of values

For instance

$primes = 1,3,5,7,11,13,17,19,23,29,31,37,41,43,47

if you want to test if 7 is a member of the collection

$candidate = 7
$primes -contains $candidate
True

Likewise testing 4

$candidate = 4
$primes -contains $candidate
False

A question on the forum asked about testing if a remote machine could be reached before using Invoke-Command against it.

The usual way to test if you can reach a remote machine is to ping it

PS> Test-Connection -ComputerName $env:COMPUTERNAME -Quiet
True

That shows you can reach the machine but it doesn’t mean that you can use Invoke-Command to send a request.

I think a better test is to use Test-WSMan

It will test if the WinRm service is running (won’t test if remoting is enabled)

$computers = "$env:COMPUTERNAME", 'NotFound'

foreach ($computer in $computers){
    $target = $computer
    if (Test-WSMan -ComputerName $computer -ErrorAction Ignore) {
        Invoke-Command -ComputerName $computer -ScriptBlock {Get-Service}
    }
    else {
        Write-Warning -Message "Couldn't connect to $computer"
    }

}

You can push the output to file or put the unreachable machine names into a file if you need to record them.