# encoding: ascii
# api: powershell
# title: Get-DevicePath
# description: Returns the corresponding device path for each drive letter
# version: 0.1
# type: function
# author: Matthew Graeber
# license: CC0
# function: Get-DevicePath
# x-poshcode-id: 4768
# x-archived: 2017-04-30T09:37:34
# x-published: 2014-01-05T21:54:00
#
#
function Get-DevicePath
{
<#
.SYNOPSIS
Returns the device paths for each volume.
Author: Matthew Graeber (@mattifestation)
License: BSD 3-Clause
.DESCRIPTION
Get-DevicePath returns the corresponding device path for each drive letter. This is useful for converting device paths to drive letters.
.EXAMPLE
Get-DevicePath
DevicePath DriveLetter
---------- -----------
\Device\HarddiskVolume2 D:
\Device\HarddiskVolume4 C:
.OUTPUTS
PSObject[]
For each mount point, a PSObject is returned representing the drive letter and device path.
#>
# Utilize P/Invoke in order to call QueryDosDevice. I prefer using
# reflection over Add-Type since it doesn't require compiling C# code.
$DynAssembly = New-Object System.Reflection.AssemblyName('SysUtils')
$AssemblyBuilder = [AppDomain]::CurrentDomain.DefineDynamicAssembly($DynAssembly, [Reflection.Emit.AssemblyBuilderAccess]::Run)
$ModuleBuilder = $AssemblyBuilder.DefineDynamicModule('SysUtils', $False)
# Define [Kernel32]::QueryDosDevice method
$TypeBuilder = $ModuleBuilder.DefineType('Kernel32', 'Public, Class')
$PInvokeMethod = $TypeBuilder.DefinePInvokeMethod('QueryDosDevice', 'kernel32.dll', ([Reflection.MethodAttributes]::Public -bor [Reflection.MethodAttributes]::Static), [Reflection.CallingConventions]::Standard, [UInt32], [Type[]]@([String], [Text.StringBuilder], [UInt32]), [Runtime.InteropServices.CallingConvention]::Winapi, [Runtime.InteropServices.CharSet]::Auto)
$DllImportConstructor = [Runtime.InteropServices.DllImportAttribute].GetConstructor(@([String]))
$SetLastError = [Runtime.InteropServices.DllImportAttribute].GetField('SetLastError')
$SetLastErrorCustomAttribute = New-Object Reflection.Emit.CustomAttributeBuilder($DllImportConstructor, @('kernel32.dll'), [Reflection.FieldInfo[]]@($SetLastError), @($true))
$PInvokeMethod.SetCustomAttribute($SetLastErrorCustomAttribute)
$Kernel32 = $TypeBuilder.CreateType()
$Max = 65536
$StringBuilder = New-Object System.Text.StringBuilder($Max)
Get-WmiObject Win32_Volume | ? { $_.DriveLetter } | % {
$ReturnLength = $Kernel32::QueryDosDevice($_.DriveLetter, $StringBuilder, $Max)
if ($ReturnLength)
{
$DriveMapping = @{
DriveLetter = $_.DriveLetter
DevicePath = $StringBuilder.ToString()
}
New-Object PSObject -Property $DriveMapping
}
}
}