List all previously-loaded PowerShell variables - powershell

Question

Is there a PowerShell command to list all previously loaded variables?
I am running some PowerShell scripts in Visual Studio and would like to list all variables that are available in the current PowerShell session.
I have tried the command:
ls variable:*;
But it returns the following:
System.Management.Automation.PSVariable
System.Management.Automation.PSVariable
System.Management.Automation.PSVariable
System.Management.Automation.PSVariable
System.Management.Automation.PSVariable
System.Management.Automation.PSVariable
System.Management.Automation.PSVariable
System.Management.Automation.PSVariable
System.Management.Automation.PSVariable
System.Management.Automation.PSVariable

Answer 1

ls variable:* should work, or Get-Variable. If these are resulting in bad output, it's due to a poorly-implemented host, not with powershell itself. If you open the standard console host (run powershell.exe), you will see that these work fine.
If you need to work around a bad host, you might have better luck dumping everything to explicit strings:
Get-Variable | Out-String
or
Get-Variable |%{ "Name : {0}`r`nValue: {1}`r`n" -f $_.Name,$_.Value }

Answer 2

Interestingly, you can just type variable, and that works too!
I figured this out because I was curious as to what ls variable:* was doing. Get-Help ls tells us that it's an alias for PowerShell's Get-ChildItem, which I know will list all of the children of an Object. So, I tried just variable, and voila!
Based on this and this, it seems that what ls variable:* is doing is telling it to do some sort of scope/namespace lookup using the * (all/any) wildcard on the variable list, which, in this case, seems extraneous (ls variable:* == ls variable: == variable).

Answer 3

I frequently noodle around, testing concepts in an interactive shell, but sometimes forget my variable names or what-all I have defined.
Here is a function I wrote to wrap Get-Variable, automatically excluding any globals that were defined when the shell started up:
function Get-UserVariable()
{
[CmdletBinding()]
param(
[Parameter(Position = 0,ValueFromPipeline=$True,ValueFromPipelineByPropertyName=$True)][String[]]$Name,
[Parameter()][Switch]$ValueOnly,
[Parameter()][String[]]$Include,
[Parameter()][String[]]$Exclude,
[Parameter()][String]$Scope
)
$varNames = $global:PSDefaultVariables + #("PSDefaultVariables")
$gvParams = #{'Scope' = "1"}
if ($PSBoundParameters.ContainsKey('Name'))
{
$gvParams['Name'] = $Name
}
if ($PSBoundParameters.ContainsKey('ValueOnly'))
{
$gvParams['ValueOnly'] = $ValueOnly
}
if ($PSBoundParameters.ContainsKey('Include'))
{
$gvParams['Include'] = $Include
}
if ($PSBoundParameters.ContainsKey('Exclude'))
{
# This is where the magic happens, folks
$gvParams['Exclude'] = ($Exclude + $varNames) | Sort | Get-Unique
}
else
{
$gvParams['Exclude'] = $varNames
}
if ($PSBoundParameters.ContainsKey('Scope'))
{
$gvParams['Scope'] = $Scope
}
gv #gvParams
<#
.SYNOPSIS
Works just like Get-Variable, but automatically excludes the names of default globals.
.DESCRIPTION
Works just like Get-Variable, but automatically excludes the names of default globals, usually captured in the user's profile.ps1 file. Insert the line:
$PSDefaultVariables = (Get-Variable).name |% { PSEscape($_) }
...wherever you want to (either before, or after, any other stuff in profile, depending on whether you want it to be excluded by running this command.)
.PARAMETER Name
(Optional) Refer to help for Get-Variable.
.PARAMETER ValueOnly
(Optional) Refer to help for Get-Variable.
.PARAMETER Include
(Optional) Refer to help for Get-Variable.
.PARAMETER Exclude
(Optional) Refer to help for Get-Variable; any names provided here will be added to the existing list stored in $PSDefaultVariables (sorted / unique'd to eliminate duplicates.)
.PARAMETER Scope
(Optional) Refer to help for Get-Variable. The only asterisk here is that the default value is "1" just to get us out of this function's own scope, but you can override with whatever value you need.
.OUTPUTS
Refer to help for Get-Variable.
.EXAMPLE
PS> $foo = 1,2,3
PS> Get-UserVariable
Name Value
---- -----
foo {1, 2, 3}
#>
}
Set-Alias -Name guv -Value Get-UserVariable
Put the following line somewhere in your profile.ps1 file, either at the very top or very bottom, depending on whether you want to automatically exclude any other variables that get defined every time you run an interactive shell:
# Remember the names of all variables set up to this point (used by Get-UserVariable function)
$PSDefaultVariables = (Get-Variable).name
Hope this is helpful!