Resolve path to short (8.3) version

Resolve-ShortPath.ps1

<#
.SYNOPSIS
Resolves a filesystem path to its DOS 8.3 short path.

.DESCRIPTION
Uses the Scripting.FileSystemObject COM API to compute the short name of each
path component and returns the resolved path object with an added `ShortPath`
property.

Only filesystem paths are supported.

.PARAMETER Path
Filesystem path (file or directory) to resolve.

.EXAMPLE
.\Resolve-ShortPath.ps1 -Path 'C:\Users\MyName\Documents\Long Folder Name'

Returns the resolved path object with its `ShortPath` value.

.OUTPUTS
System.Management.Automation.PathInfo

.NOTES
Requires Windows support for 8.3 short names and uses a COM object.
#>


#requires -version 7.4

# this is one of Stéphane BARIZIEN's public domain scripts
# the most recent version can be found at:
# https://gist.github.com/sba923/54a260dbd0fcd6672de13cf9e81b41db#file-resolve-shortpath-ps1

param([Parameter(Mandatory = $true)][string] $Path)

# derived from https://devblogs.microsoft.com/scripting/use-powershell-to-display-short-file-and-folder-names/

$item = Get-Item -Path $Path -ErrorAction SilentlyContinue

if ($null -eq $item)
{
    Write-Error ("Cannot find path '{0}' because it does not exist." -f $Path)
    $null
    Exit(1)
}

if ($item.PSProvider.Name -ne 'FileSystem')
{
    Write-Error ("Only filesystem paths are supported")
    $null
    Exit(1)
}

$fso = New-Object -ComObject Scripting.FileSystemObject
function GetShortPath([string] $Path)
{
    $item = Get-Item -LiteralPath $Path -Force
    if ($item.PSIsContainer)
    {
        if ($item.PSParentPath -eq '')
        {
            return $item.FullName
        }
        $shortname = $fso.getfolder($item.FullName).ShortName 
        $parentpath = Split-Path -Path $Path -Parent
        return (Join-Path -Path (GetShortPath -Path $parentpath) -ChildPath $shortname)
    }
    else
    {
        $shortname = $fso.getfile($item.FullName).ShortName 
        $parentpath = Split-Path -Path $Path -Parent
        return (Join-Path -Path (GetShortPath -Path $parentpath) -ChildPath $shortname)
    } 
}

# get a PathInfo object for the item, then clone it so we're able to set the DefaultDisplayPropertySet
$resolvedpath = (Resolve-Path -Path $Path) | Select-Object -Property *

# compute the full short path i.e. short name for each of the path components
$shortpath = GetShortPath -Path $Path

# add ShortPath property
Add-Member -InputObject $resolvedpath -MemberType NoteProperty -Name ShortPath -Value $shortpath

# set the default property to 'ShortPath'
# derived from https://learn-powershell.net/2013/08/03/quick-hits-set-the-default-property-display-in-powershell-on-custom-objects/
#Give this object a unique typename
$resolvedpath.PSObject.Typenames.Insert(0, 'ResolvedShortPath')
#Configure a default display set
$defaultDisplaySet = 'ShortPath'
#Create the default property display set
$defaultDisplayPropertySet = New-Object System.Management.Automation.PSPropertySet('DefaultDisplayPropertySet', [string[]]$defaultDisplaySet)
$PSStandardMembers = [System.Management.Automation.PSMemberInfo[]]@($defaultDisplayPropertySet)
$resolvedpath | Add-Member MemberSet PSStandardMembers $PSStandardMembers

# output the final object
$resolvedpath