PowerShell Script Issues with Variable Values - powershell

Question

I am trying to write this script to restart computers only if they are Offline. The script for getting user infomration works but I cannot get the variable values for the restart portion at the bottom of the script. Does anyone have a suggestion? I am somewhat new to Powershell, but writing code. Example of my script follows:
Function Get-LoggedOnUser
{
Param
(
$ComputerName = $env:COMPUTERNAME,
$Credential
)
Function Test-RemoteRegistry
{
Param
(
[Parameter(Mandatory = $False)]
[switch]$Enable
,
[Parameter(Mandatory = $False)]
[switch]$Disable
,
[Parameter(ValueFromPipeline=$True)]
[String[]]$ComputerName = $env:COMPUTERNAME
)
Begin
{
$PipelineInput = (-not $PSBOUNDPARAMETERS.ContainsKey("ComputerName")) -and (-not $ComputerName)
Function Test ($Computer)
{
Try
{
[Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey([Microsoft.Win32.RegistryHive]::LocalMachine, $Computer) | Out-Null
#20ms faster than Get-Service per computer! Not sure how to handle/check things like the firewall though...
#If we hit here without error Remote Reg is enabled.
If ($Disable)
{
Try
{
Get-Service -Name RemoteRegistry -ComputerName $Computer | Set-Service -Status Stopped -ErrorAction Stop
Return $False
#If we hit here without error Remote Reg is now disabled.
}
Catch
{
Return $True
#If we hit here, we couldn't stop remote registry.
}
}
Else
{
Return $True
}
}
Catch
{
If ($Enable)
{
Try
{
Get-Service -Name RemoteRegistry -ComputerName $Computer | Set-Service -Status Running -ErrorAction Stop
Return $True
#If we hit here without error Remote Reg is now enabled.
}
Catch
{
Return $False
#If we hit here, we couldn't start remote registry.
}
}
Else
{
Return $False
#If we hit here remote registry is disabled.
}
}
}
}
Process
{
If ($PipelineInput)
{
Test $_
}
Else
{
$ComputerName | ForEach-Object {
Test $_
}
}
}
}
Foreach ($Computer in $Computername)
{
$Online = $False
$User = $False
$Locked = $False
If (Test-Connection $Computer -Count 2 -Quiet)
{
$Online = $True
If ($Credential)
{
$User = Get-WmiObject -Class Win32_ComputerSystem -ComputerName $Computer -Credential $Credential | Select-Object -ExpandProperty UserName -ErrorAction Stop
}
Else
{
$User = Get-WmiObject -Class Win32_ComputerSystem -ComputerName $Computer | Select-Object -ExpandProperty UserName -ErrorAction Stop
}
If (Test-RemoteRegistry -Enable -ComputerName $Computer)
{
If ((Get-Process logonui -ComputerName $Computer -ErrorAction SilentlyContinue) -and ($user))
{
$Locked = $True
}
}
}
$Output = New-Object PSObject
$Output | Add-Member noteproperty ComputerName $Computer
$Output | Add-Member noteproperty Online $Online
$Output | Add-Member noteproperty Username $User
$Output | Add-Member noteproperty Locked $Locked
$Output
}
}
Get-LoggedOnUser
If (($Online) -eq $False)
{Shutdown /r t 0 /m \\$Computername}
ELSE
{Write-host 'HELLO $Online $Computername'}
I just want this for a single user as I am using PDQ Inventory to roll out the script. The variables at the end of the script are $null?

Answer 1

Variables defined in a child scope - in which functions run by default - are never seen by the calling scope. See the conceptual about_Scopes help topic
It's best for functions to communicate values to the caller via their output ("return value"), which you're function is already doing: it outputs objects whose properties contain the values of interest.
Therefore:
Get-LoggedOnUser |
ForEach-Object { # Loop over all output objects
# Refer to the object at hand via the automatic $_ variable.
# Note the use of "..." (expandable strings) so as to support
# expansion (string interpolation).
if (-not $_.Online) { Shutdown /r t 0 /m "\\$($_.ComputerName)" }
else { "HELLO $($_.Online) $($_.ComputerName)" }
}