Get-LinkTarget.ps1

## Get-LinkTarget.ps1
# Note: Script should be symlinked as follows:
# Get-LinkTarget.ps1 -> Resolve-UNCPath.ps1
# Get-LinkTarget.ps1 -> Resolve-JunctionPath.ps1
# Get-LinkTarget.ps1 -> Resolve-HardlinkPath.ps1
# Get-LinkTarget.ps1 -> Resolve-SymlinkPath.ps1
# Get-LinkTarget.ps1 -> Resolve-ReparsePointPath.ps1

function Global:Get_UNCPath($l_dir)
{
    if( ( ([System.Management.Automation.PSTypeName]'System.Win32').Type -eq $null) -or
          ([system.win32].getmethod('GetSymbolicLinkTarget') -eq $null ) )
    {
        Add-Type -MemberDefinition @"
private const int CREATION_DISPOSITION_OPEN_EXISTING = 3;
private const int FILE_FLAG_BACKUP_SEMANTICS = 0x02000000;

[DllImport("kernel32.dll", EntryPoint = "GetFinalPathNameByHandleW", CharSet = CharSet.Unicode, SetLastError = true)]
 public static extern int GetFinalPathNameByHandle(IntPtr handle, [In, Out] StringBuilder path, int bufLen, int flags);

[DllImport("kernel32.dll", EntryPoint = "CreateFileW", CharSet = CharSet.Unicode, SetLastError = true)]
 public static extern SafeFileHandle CreateFile(string lpFileName, int dwDesiredAccess, int dwShareMode,
 IntPtr SecurityAttributes, int dwCreationDisposition, int dwFlagsAndAttributes, IntPtr hTemplateFile);

 public static string GetSymbolicLinkTarget(System.IO.DirectoryInfo symlink)
 {
     SafeFileHandle directoryHandle = CreateFile(symlink.FullName, 0, 2, System.IntPtr.Zero, CREATION_DISPOSITION_OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, System.IntPtr.Zero);
     if(directoryHandle.IsInvalid)
     {
         throw new Win32Exception(Marshal.GetLastWin32Error());
     }
     StringBuilder path = new StringBuilder(512);
     int size = GetFinalPathNameByHandle(directoryHandle.DangerousGetHandle(), path, path.Capacity, 0);
     if (size<0)
     {
         throw new Win32Exception(Marshal.GetLastWin32Error());
     }
     // The remarks section of GetFinalPathNameByHandle mentions the return being prefixed with "\\?\"
     // More information about "\\?\" here -> http://msdn.microsoft.com/en-us/library/aa365247(v=VS.85).aspx
     string sPath = path.ToString();
     if( sPath.Length>8 && sPath.Substring(0,8) == @"\\?\UNC\" )
     {
         return @"\" + sPath.Substring(7);
     }
     else if( sPath.Length>4 && sPath.Substring(0,4) == @"\\?\" )
     {
         return sPath.Substring(4);
     }
     else
     {
         return sPath;
     }
 }
"@ -Name Win32 -NameSpace System -UsingNamespace System.Text,Microsoft.Win32.SafeHandles,System.ComponentModel
    }
    [System.Win32]::GetSymbolicLinkTarget($l_dir)
}

function Global:Get_JunctionTarget([string]$p_path)
{
    $l_target = fsutil reparsepoint query $p_path | where-object { $_ -imatch 'Print Name\:' } | foreach-object { $_ -replace 'Print Name\:\s*','' }
    if( $l_target -imatch "(^[A-Z])\:\\" )
    {
        $l_drive = $matches[1]
        $l_uncPath = Get_UncPath $p_path
        if( $l_uncPath -imatch "(^\\\\[^\\]*\\)" )
        {
            $l_machine = $matches[1]
            $l_target = $l_target -replace "^$l_drive\:","$l_machine$l_drive$"
        }
    }
    $l_target
}

function Global:Get_LinkTargetPath
{
    foreach($item in $args)
    {
        $itemTarget = try { (Get-Item $item -Force).Target } catch {}
        if( !$itemTarget )
        {
            continue
        }
        if( $itemTarget)
        {
            $itemTarget # TODO: resolve target PSPath
        }
    }
}

if( !( $MyInvocation.InvocationName -eq '.' -or $MyInvocation.Line -eq '' ) )
{
    if( $null -ne $MyInvocation.MyCommand.Name )
    {
        switch -Wildcard ( $MyInvocation.MyCommand.Name )
        {
            "*UNC*"        { Get_UNCPath $args }
            "*Junction*"   { Get_JunctionPath $args }
            "*Reparse*"    { Get_JunctionPath $args }
            "*Sym*"        { Get_LinkTargetPath $args }
            "*Hard*"       { Get_LinkTargetPath $args }
        }
    }
}
else {}