PowerShell Built-in variables $PSScriptRoot
Example
Get-ChildItem -Path $PSScriptRoot
This example retrieves the list of child items (directories and files) from the folder where the script file resides.
The $PSScriptRoot automatic variable is $null if used from outside a PowerShell code file. If used inside a PowerShell script, it automatically defined the fully-qualified filesystem path to the directory that contains the script file.
In Windows PowerShell 2.0, this variable is valid only in script modules (.psm1). Beginning in Windows PowerShell 3.0, it is valid in all scripts.
