Powershell script to copy Steam screenshots folders from one drive to another, for backing up screenshots or migrating to a new drive

copy-screenshots.ps1

param(
    [string]$source_drive_letter,
    [string]$destination_drive_letter
)

if ([string]::IsNullOrEmpty($source_drive_letter))
{
    Write-Output "No source_drive_letter argument provided"
    exit
}

if ($source_drive_letter.Length -gt 1)
{
    Write-Output "source_driver_letter argument longer than 1 character"
    exit
}

$source_drive_letter = $source_drive_letter.ToUpper();

if (-Not (Test-Path -Path "${source_drive_letter}:\"))
{
    Write-Output "source_drive_letter '$source_drive_letter' does not exist"
    exit
}

if ([string]::IsNullOrEmpty($destination_drive_letter))
{
    Write-Output "No destination_drive_letter argument provided"
    exit
}

if ($destination_drive_letter.Length -gt 1)
{
    Write-Output "destination_driver_letter argument longer than 1 character"
    exit
}

$destination_drive_letter = $destination_drive_letter.ToUpper()

if (-Not (Test-Path -Path "${destination_drive_letter}:\"))
{
    Write-Output "destination_drive_letter '$destination_drive_letter' does not exist"
    exit
}

$source_path = "${source_drive_letter}:\Program Files (x86)\Steam\"

if (-Not (Test-Path -Path "$source_path"))
{
    Write-Output "Steam folder '$source_path' does not exist"
    exit
}

$screenshot_folders = Get-ChildItem "$source_path" screenshots -Recurse

foreach ($screenshot_folder in $screenshot_folders)
{
    $screenshot_source = $screenshot_folder.FullName
    $screenshot_dest = $screenshot_source -replace "^${source_drive_letter}", "${destination_drive_letter}"
    Write-Output "Copying ${screenshot_source} to ${screenshot_dest}"

    mkdir -Path "$screenshot_dest" -Force
    Get-ChildItem -Path "$screenshot_source" -Recurse | Copy-Item -Destination "$screenshot_dest"
}