In the previous tip we illustrated how you can identify built-in PowerShell variables with an approach like this:
$ps = [PowerShell]::Create() $null = $ps.AddScript('$null=$host;Get-Variable') $ps.Invoke() $ps.Runspace.Close() $ps.Dispose()
Now let’s do the opposite, and create a function that dumps only your own variables:
function Get-UserVariable ($Name = '*') { # these variables may exist in certain environments (like ISE, or after use of foreach) $special = 'ps','psise','psunsupportedconsoleapplications', 'foreach', 'profile' $ps = [PowerShell]::Create() $null = $ps.AddScript('$null=$host;Get-Variable') $reserved = $ps.Invoke() | Select-Object -ExpandProperty Name $ps.Runspace.Close() $ps.Dispose() Get-Variable -Scope Global | Where-Object Name -like $Name | Where-Object { $reserved -notcontains $_.Name } | Where-Object { $special -notcontains $_.Name } | Where-Object Name }
Now it’s really easy to identify all the variables you (or your scripts) have created that still linger around in memory:
PS> Get-UserVariable
Name Value
---- -----
hash {Extensions, Link, Options, GPOLink...}
prop lParam
reserved {$, ?, ^, args...}
result {System.Management.Automation.PSVariable, System.Management.Automation.Ques...
varCount 43
PS> Get-UserVariable -Name pr*
Name Value
---- -----
prop lParam
To clean up your runspace, you could now delete all your variables in one line:
PS> Get-UserVariable
Name Value
---- -----
hash {Extensions, Link, Options, GPOLink...}
key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\H...
prop lParam
reserved {$, ?, ^, args...}
result {System.Management.Automation.PSVariable, System.Management.Automation.Ques...
varCount 43
PS> Get-UserVariable | Remove-Variable
PS> Get-UserVariable
PS>
