Finding All Variables in a Script

by Jun 15, 2017

In the previous tip we illustrated how you can analyze the content of a script block and search for variables or commands. The same is possible for text-based scripts. The script below will analyze itself and dump variables and commands:

$filepath = $PSCommandPath
$tokens = $errors = $null

$ast = [System.Management.Automation.Language.Parser]::ParseFile($filepath, [ref]$tokens, [ref]$errors )

# find variables
$ast.FindAll( { $true }, $true) | 
  Where-Object { $_.GetType().Name -eq 'VariableExpressionAst' } |
  Select-Object -Property VariablePath -ExpandProperty Extent |
  Select-Object -Property * -ExcludeProperty *ScriptPosition |
  Out-GridView -Title 'Variables'

# find commands
$ast.FindAll( { $true }, $true)  | 
  Where-Object { $_.GetType().Name -eq 'CommandAst' } |
  Select-Object -ExpandProperty Extent  |
  Select-Object -Property * -ExcludeProperty *ScriptPosition |
  Out-GridView -Title 'Commands'

Just make sure the script is saved to disk, or specify a different path to a valid script in $filepath.

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