By default it seems PowerShell uses the ANSI versions of FindFirstFile and FindNextFile, and is therefore limited to MAX_PATH - 260 characters in total. This PowerShell script uses in-line compiled VB.Net to call the wide unicode versions - FindFirstFileW and FindNextFileW - to bypass the ANSI MAX_PATH limitations. The results are essentially the same as a 'dir /s/b/a-d' that won't return with 'The filename or extension is too long.' or 'The directory name x is too long' errors.
If you use '/l', the script will only return deep paths, and also provide the 8.3 equivalent to the deep path - a useful method to access these files. For example, using this method, you can access a file with UNC (eg \\server\share) over 18 levels deep ((260-16)/13).
Note that these wide calls only bypass MAX_PATH when using a mapped drive with the \\?\ prefix to disable path parsing. Just specify a mapped drive or local path normally, eg c:\temp, the script will automatically prepend \\?\
I've been experimenting with using PowerShell to dynamically compile VB.Net or C# code, and within that managed code, calling unmanaged platform invoke operations to get to APIs. I like the flexibility of using a scripting language rather than compiled code, and while this certainly isn't as functional as 'dir', it was useful to me when at least trying to get a list of deep files.
## FindFiles.ps1 ##
param(
[string] $dirRoot = $pwd,
[string] $Spec = "*.*",
[bool] $longOnly = $false
)
# Changes:
# 23/05/2008, Wayne Martin, Added the option to only report +max_path entries, and report the short path of those directories (which makes it easier to access them)
#
#
# Description:
# Use the wide unicode versions to report a directory listing of all files, including those that exceed the MAX_PATH ANSI limitations
#
# Assumptions, this script works on the assumption that:
# There's a console to write the output from the compiled VB.Net
#
# Author:
# Wayne Martin, 15/05/2008
#
# Usage
# PowerShell . .\FindFiles.ps1 -d c:\temp -s *.*
#
# PowerShell . .\FindFiles.ps1 -d c:\temp
#
# PowerShell . .\FindFiles.ps1 -d g: -l $true
#
# References:
# http://msdn.microsoft.com/en-us/library/aa364418(VS.85).aspx
# http://blogs.msdn.com/jaredpar/archive/2008/03/14/making-pinvoke-easy.aspx
$provider = new-object Microsoft.VisualBasic.VBCodeProvider
$params = new-object System.CodeDom.Compiler.CompilerParameters
$params.GenerateInMemory = $True
$refs = "System.dll","Microsoft.VisualBasic.dll"
$params.ReferencedAssemblies.AddRange($refs)
$txtCode = @'
Imports System
Imports System.Runtime.InteropServices
Class FindFiles
Const ERROR_SUCCESS As Long = 0
Private Const MAX_PREFERRED_LENGTH As Long = -1
_
Public Structure WIN32_FIND_DATAW
'''DWORD->unsigned int
Public dwFileAttributes As UInteger
'''FILETIME->_FILETIME
Public ftCreationTime As FILETIME
'''FILETIME->_FILETIME
Public ftLastAccessTime As FILETIME
'''FILETIME->_FILETIME
Public ftLastWriteTime As FILETIME
'''DWORD->unsigned int
Public nFileSizeHigh As UInteger
'''DWORD->unsigned int
Public nFileSizeLow As UInteger
'''DWORD->unsigned int
Public dwReserved0 As UInteger
'''DWORD->unsigned int
Public dwReserved1 As UInteger
'''WCHAR[260]
_
Public cFileName As String
'''WCHAR[14]
_
Public cAlternateFileName As String
End Structure
_
Public Structure FILETIME
'''DWORD->unsigned int
Public dwLowDateTime As UInteger
'''DWORD->unsigned int
Public dwHighDateTime As UInteger
End Structure
Partial Public Class NativeMethods
'''Return Type: HANDLE->void*
'''lpFileName: LPCWSTR->WCHAR*
'''lpFindFileData: LPWIN32_FIND_DATAW->_WIN32_FIND_DATAW*
_
Public Shared Function FindFirstFileW( ByVal lpFileName As String, ByRef lpFindFileData As WIN32_FIND_DATAW) As System.IntPtr
End Function
'''Return Type: BOOL->int
'''hFindFile: HANDLE->void*
'''lpFindFileData: LPWIN32_FIND_DATAW->_WIN32_FIND_DATAW*
_
Public Shared Function FindNextFileW( ByVal hFindFile As System.IntPtr, ByRef lpFindFileData As WIN32_FIND_DATAW) As Boolean
End Function
'''Return Type: BOOL->int
'''hFindFile: HANDLE->void*
_
Public Shared Function FindClose(ByVal hFindFile As System.IntPtr) As Boolean
End Function
'''Return Type: DWORD->unsigned int
'''lpszLongPath: LPCWSTR->WCHAR*
'''lpszShortPath: LPWSTR->WCHAR*
'''cchBuffer: DWORD->unsigned int
_
Public Shared Function GetShortPathNameW( ByVal lpszLongPath As String, ByVal lpszShortPath As System.Text.StringBuilder, ByVal cchBuffer As UInteger) As UInteger
End Function
End Class
Private Const FILE_ATTRIBUTE_DIRECTORY As Long = &H10
Dim FFW as New NativeMethods
Function Main(ByVal dirRoot As String, ByVal sFileSpec As String, Byval longOnly As Boolean) As Long
Dim result As Long
result = FindFiles(dirRoot, sFileSpec, longOnly)
main = result ' Return the result
End Function
Function FindFiles(ByRef sDir As String, ByVal sFileSpec as String, Byval longOnly As Boolean) As Long
Const MAX_PATH As Integer = 260
Dim FindFileData as WIN32_FIND_DATAW
Dim hFile As Long
Dim sFullPath As String
Dim sFullFile As String
Dim length as UInteger
Dim sShortPath As New System.Text.StringBuilder()
sFullPath = "\\?\" & sDir
'console.writeline(sFullPath & "\" & sFileSpec)
hFile = FFW.FindFirstFileW(sFullPath & "\" & sFileSpec, FindFileData) ' Find the first object
if hFile > 0 Then ' Has something been found?
If (FindFileData.dwFileAttributes AND FILE_ATTRIBUTE_DIRECTORY) <> FILE_ATTRIBUTE_DIRECTORY Then ' Is this a file?
sFullFile = sFullPath & "\" & FindFileData.cFileName
If (longOnly AND sFullFile.Length >= MAX_PATH) Then
length = FFW.GetShortPathNameW(sFullPath, sShortPath, sFullPath.Length) ' GEt the 8.3 path
console.writeline(sFullFile & " " & sshortpath.ToString()) ' Yes, report the full path and filename
ElseIf (NOT longOnly)
console.writeline(sFullFile)
End If
End If
While FFW.FindNextFileW(hFile, FindFileData) ' For all the items in this directory
If (FindFileData.dwFileAttributes AND FILE_ATTRIBUTE_DIRECTORY) <> FILE_ATTRIBUTE_DIRECTORY Then ' Is this a file?
sFullFile = sFullPath & "\" & FindFileData.cFileName
If (longOnly AND sFullFile.Length >= MAX_PATH) Then
length = FFW.GetShortPathNameW(sFullPath, sShortPath, sFullPath.Length) ' GEt the 8.3 path
console.writeline(sFullFile & " " & sshortpath.ToString()) ' Yes, report the full path and filename
ElseIf (NOT longOnly)
console.writeline(sFullFile)
End If
End If
End While
FFW.FindClose(hFile) ' Close the handle
FindFileData = Nothing
End If
hFile = FFW.FindFirstFileW(sFullPath & "\" & "*.*", FindFileData) ' Repeat the process looking for sub-directories using *.*
if hFile > 0 Then
If (FindFileData.dwFileAttributes AND FILE_ATTRIBUTE_DIRECTORY) AND _
(FindFileData.cFileName <> ".") AND (FindFileData.cFileName <> "..") Then
Call FindFiles(sDir & "\" & FindFileData.cFileName, sFileSpec, longOnly) ' Recurse
End If
While FFW.FindNextFileW(hFile, FindFileData)
If (FindFileData.dwFileAttributes AND FILE_ATTRIBUTE_DIRECTORY) AND _
(FindFileData.cFileName <> ".") AND (FindFileData.cFileName <> "..") Then
Call FindFiles(sDir & "\" & FindFileData.cFileName, sFileSpec, longOnly) ' Recurse
End If
End While
FFW.FindClose(hFile) ' Close the handle
FindFileData = Nothing
End If
End Function
end class
'@
$cr = $provider.CompileAssemblyFromSource($params, $txtCode)
if ($cr.Errors.Count) {
$codeLines = $txtCode.Split("`n");
foreach ($ce in $cr.Errors)
{
write-host "Error: $($codeLines[$($ce.Line - 1)])"
write-host $ce
#$ce out-default
}
Throw "INVALID DATA: Errors encountered while compiling code"
}
$mAssembly = $cr.CompiledAssembly
$instance = $mAssembly.CreateInstance("FindFiles")
$result = $instance.main($dirRoot, $Spec, $longOnly)
Wayne's World of IT (WWoIT), Copyright 2008 Wayne Martin.
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