Powershell: Combining Variables in Output

Question

I'm trying to put together a very simple code that outputs the server name, the last reboot date, and then the difference in hours and days. I've tried several iterations of Write-Host, but I can't seem to get the output I expect. The output should be something like this:
ServerName | Reboot Date | Time Running (Day, Hours)

Here is the code:

begin {}
process {
  foreach($server in (gc d:\win_IP.txt)){
    if(Test-Connection -ComputerName $server -Count 1 -ea 0) {
      $strFQDN = [System.Net.Dns]::GetHostbyAddress($server) | Select-Object HostName -ErrorAction "SilentlyContinue"
      $wmi = Get-WmiObject -Class Win32_OperatingSystem -Computer $server 
      $strDate = $wmi.ConvertToDateTime($wmi.LastBootUpTime)
      $strDiff = [DateTime]::Now - $wmi.ConvertToDateTime($wmi.LastBootUpTime) | Format-Table Days, Hours
    } else {
      Write-Verbose "$server is offline"
    }            
  }
}            

end {}

If someone could explain just how combining variables works, as well as how to format the output, I'd really appreciate it.

Thanks in advance.

Answer 1

Try this:

foreach ($server in (Get-Content "d:\win_IP.txt")){
    if (Test-Connection -ComputerName $server -Count 1 -Quiet) {
        $strFQDN = [System.Net.Dns]::GetHostbyAddress($server)
        $wmi = Get-WmiObject -Class Win32_OperatingSystem -Computer $server 
        $strDate = $wmi.ConvertToDateTime($wmi.LastBootUpTime)
        $strDiff = [DateTime]::Now - $strDate

        [PSCustomObject]@{
            "ServerName" = $strFQDN.HostName
            "Reboot Date" = $strDate
            "Time Running" = "$($strDiff.Days) days, $($strDiff.Hours) hours"
        }

    } else {
        Write-Verbose "$server is offline"
    }            
}

What I did was store each field in a single object, then just outputted that object without formatting it. Typically not a good idea to format objects because then they are converted to strings and cannot be used for anything other than outputting to host/file.

Answer 2

Entbark's answer is probably what you're after—if you're using PowerShell 3.0. The HashTable-to-Object notation doesn't work in PowerShell 2.0.

Instead, see below for more options. The main point, though, is that you combine variables by creating a new object and adding the variables as properties to that object.

(Also, I wasn't aware of Test-Connection, is it just me or is it super slow?)

Intro:

ForEach ($server in (gc 'D:\win_IP.txt')) {
    $Pinger = New-Object System.Net.NetworkInformation.Ping
    if( $Pinger.Send( $server, 500 ).Status -eq "Success" ) {
        $strFQDN = [System.Net.Dns]::GetHostbyAddress($server) |
            Select HostName -ErrorAction "SilentlyContinue"
        $wmi = Get-WmiObject -Class Win32_OperatingSystem -Computer $server 
        $strDate = $wmi.ConvertToDateTime($wmi.LastBootUpTime)
        $strDiff = [DateTime]::Now - $strDate

Combine Variables Option 1:

        $OutObject = New-Object PSObject
        $OutObject | Add-Member NoteProperty 'FQDN' ($strFQDN)
        $OutObject | Add-Member NoteProperty 'Date' ($strDate)
        $OutObject | Add-Member NoteProperty 'Diff' ($strDiff)

        # 1 A:
        Write-Output $OutObject

        # 1 B:
        $OutObject | Format-Table  

Combine Variables Option 2:

        Write-Output ( (New-Object PSObject) |
            Add-Member NoteProperty 'FQDN' ($strFQDN) -PassThru |
            Add-Member NoteProperty 'Date' ($strDate) -PassThru |
            Add-Member NoteProperty 'Diff' ($strDiff) -PassThru )

Combine Variables Option 2B:

        ( (New-Object PSObject) |
            Add-Member NoteProperty 'FQDN' ($strFQDN) -PassThru |
            Add-Member NoteProperty 'Date' ($strDate) -PassThru |
            Add-Member NoteProperty 'Diff' ($strDiff) -PassThru ) | Format-Table

Outro:

    } else {
        Write-Verbose "$server is offline"
    }
}