Functions/GenXdev.Windows/Get-ActiveUser.ps1
|
################################################################################ <# .SYNOPSIS Retrieves a list of unique usernames from currently active system processes. .DESCRIPTION Queries all running processes on the system, extracts the associated username for each process, and returns a deduplicated list of users who have active processes. This is useful for system administration and security monitoring. .EXAMPLE Get-ActiveUser Returns a list of all unique usernames with active processes. .EXAMPLE gusers Uses the alias to get the same results. #> function Get-ActiveUser { [CmdletBinding()] [Alias("gusers")] param() begin { # store original error preferences for restoration $originalEAP = $ErrorActionPreference $originalErrorView = $ErrorView # set strict error handling $ErrorActionPreference = 'Stop' $ErrorView = 'DetailedView' # inform about the start of process enumeration Microsoft.PowerShell.Utility\Write-Verbose "Starting to enumerate all system processes..." } process { try { # get all processes with associated usernames (requires admin privileges) $processes = Microsoft.PowerShell.Management\Get-Process * ` -IncludeUserName ` -ErrorAction Stop # extract and deduplicate usernames from process list $users = $processes | Microsoft.PowerShell.Core\ForEach-Object UserName | Microsoft.PowerShell.Utility\Select-Object -Unique # return the filtered list $users } catch [System.UnauthorizedAccessException] { Microsoft.PowerShell.Utility\Write-Error ` -Message "Access denied while retrieving processes. Run with elevated privileges." ` -Exception $_.Exception ` -Category PermissionDenied ` -ErrorId 'ActiveUserAccessDenied' throw } catch [System.ArgumentException] { Microsoft.PowerShell.Utility\Write-Error ` -Message "Invalid argument provided when retrieving processes." ` -Exception $_.Exception ` -Category InvalidArgument ` -ErrorId 'ActiveUserInvalidArgument' throw } catch { Microsoft.PowerShell.Utility\Write-Error ` -Message "Unexpected error while retrieving active users: $_" ` -Exception $_.Exception ` -Category OperationStopped ` -ErrorId 'ActiveUserUnexpectedError' throw } } end { # restore original error handling settings $ErrorActionPreference = $originalEAP $ErrorView = $originalErrorView # output completion status if users were found if ($null -ne $users) { Microsoft.PowerShell.Utility\Write-Verbose ` "Process completed. Found $($users.Count) unique active users." } else { Microsoft.PowerShell.Utility\Write-Verbose ` "Process completed. No active users found or an error occurred." } } } ################################################################################ |