PowerShell create a new object and add the values to an array

Question

What I am trying to achieve here is add the servers and the updates that are not installed on the server to an array and create a new object that is going to display the names of the servers in one column and the missing updates on another column, but at the end I am getting an empty Grid-View table.

The values for the servers and updates are read from a file.

Write-Host
#Read the password from stdin and store it in a variable
$password = Read-Host -AsSecureString -Prompt "Enter your password"
Write-Host
#Get credentials and password for later user
$cred = New-Object System.Management.Automation.PSCredential ("Administrator@testing.local", $password )

#Get the list of available servers to test
$servers = Get-Content -Path $HOME\Desktop\servers.txt
#Get the list of available updates that need to be installed on the server
$available_updates = Get-Content $HOME\Desktop\update.txt

$add_updates = @()
$add_updates_and_servers = @()

#Get each server name from the list and execute the following commands
foreach ($server in $servers) {

    #Test if the server is reponding
    $ping = Test-Connection $server -Count 1 -Quiet

    #If the above command returns True continue
    if ($ping -eq "True") {

        #Write a message saying Testing server_name
        Write-Host "Testing $server"
        
        foreach ($update in $available_updates) {

            #Check if update is installed
            $updates_from_os = Invoke-Command -ComputerName $server -Credential $cred -ScriptBlock { Get-HotFix | Select-Object -Property HotFixID | Where-Object -Property HotFixID -EQ $Using:update } -HideComputerName | Select-Object -ExpandProperty HotFixID

            if (!$updates_from_os) {
                
                $add_updates += $update

            }
        }

        New-Object -TypeName PSObject -Property $updates -OutVariable final
            
        $updates = @{

            "Server"  = $server
            "Updates" = $add_updates

        }
    }

    $add_updates_and_servers += $final
}

$add_updates_and_servers | Out-GridView

iRon · Accepted Answer · 2020-12-24T17:22:05.660

For what is probably happening with your script:
I suspect that each time you calling the statement New-Object -TypeName PSObject -Property $updates -OutVariable final You overwriting any previous created $final object which references to the same objects as your $add_updates_and_servers collection.

Anyways, try to avoid using the increase assignment operator (+=) to create a collection, instead stream the results to a variable (or even better, directly to next/final cmdlet: ... }| Out-GridView).
Something like:

$add_updates_and_servers = foreach ($server in $servers) {
    $ping = Test-Connection $server -Count 1 -Quiet
    if ($ping -eq "True") {
        Write-Host "Testing $server"
        $add_updates = @(
            foreach ($update in $available_updates) {
                $updates_from_os = Invoke-Command -ComputerName $server -Credential $cred -ScriptBlock { Get-HotFix | Select-Object -Property HotFixID | Where-Object -Property HotFixID -EQ $Using:update } -HideComputerName | Select-Object -ExpandProperty HotFixID
                if (!$updates_from_os) { $update }
            }
        )
        [PSCustomObject]@{
            "Server"  = $server
            "Updates" = $add_updates
        }
    }
}

Note: in case you want each $update in a separate column, also have a look at: Not all properties displayed

Thanks for the response and help, that fixed it. Now I can see the output in a Out-GridView or even save it to a .csv file. — Stefan Spiroski, Dec 25 '20 at 07:14

PowerShell create a new object and add the values to an array

1 Answers1