Not all PowerShell cmdlets ship with PowerShell. Many are part of 3rd party modules which in turn ship when you install certain software, or use certain Windows versions.
In the previous part we produced a function that dumps all external commands found in a script. With just a little extra effort, this can be turned into a useful compatibility report: any cmdlet originates from a module, and any module with a name starting with “Microsoft.PowerShell” ships with PowerShell. Any other modules are specific to certain Windows versions or 3rd party extensions.
Check out this function:
function Get-ExternalCommand { param ( [Parameter(Mandatory)][string] $Path ) function Get-ContainedCommand { param ( [Parameter(Mandatory)][string] $Path, [string][ValidateSet('FunctionDefinition','Command')] $ItemType ) $Token = $Err = $null $ast = [Management.Automation.Language.Parser]::ParseFile($Path, [ref] $Token, [ref] $Err) $ast.FindAll({ $args[0].GetType().Name -eq "${ItemType}Ast" }, $true) } $functionNames = Get-ContainedCommand $Path -ItemType FunctionDefinition | Select-Object -ExpandProperty Name $commands = Get-ContainedCommand $Path -ItemType Command $commands | Where-Object { $commandName = $_.CommandElements[0].Extent.Text $commandName -notin $functionNames } | ForEach-Object { $_.GetCommandName() } | Sort-Object -Unique | ForEach-Object { $module = (Get-Command -name $_).Source $builtIn = $module -like 'Microsoft.PowerShell.*' [PSCustomObject]@{ Command = $_ BuiltIn = $builtIn Module = $module } } }
Here is a sample report from a PowerShell script listing all external cmdlets and whether they are part of PowerShell or come from external modules:
PS> Get-ExternalCommand -Path $Path Command BuiltIn Module ------- ------- ------ ConvertFrom-StringData True Microsoft.PowerShell.Utility Get-Acl True Microsoft.PowerShell.Security Get-ItemProperty True Microsoft.PowerShell.Management Get-Service True Microsoft.PowerShell.Management Get-WmiObject True Microsoft.PowerShell.Management New-Object True Microsoft.PowerShell.Utility out-default True Microsoft.PowerShell.Core Test-Path True Microsoft.PowerShell.Management Where-Object True Microsoft.PowerShell.Core write-host True Microsoft.PowerShell.Utility PS>
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