Excel VBA efficient get file names function

Question

I need to get a collection of file names from a folder on a remote server using VBA in excel 2010. I have a function that works and in the majority of cases it would do the

Answer 1

Ok, I have found a solution that works for my situation and perhaps others will find it useful too. This soution uses the windows API and gets me the filenames in 1 second or less where as the FSO method was taking several minutes. It still involves a loop so i'm not certain why it is so much faster but it is.

This takes a path like "c:\windows\" and returns a collection of all the files (and directories) in that folder. The exact parameters I have used require windows 7 or newer, see the comments in the declarations.

'for windows API call to FindFirstFileEx
Private Const INVALID_HANDLE_VALUE = -1
Private Const MAX_PATH = 260

Private Type FILETIME
    dwLowDateTime   As Long
    dwHighDateTime  As Long
End Type

Private Type WIN32_FIND_DATA
    dwFileAttributes    As Long
    ftCreationTime      As FILETIME
    ftLastAccessTime    As FILETIME
    ftLastWriteTime     As FILETIME
    nFileSizeHigh       As Long
    nFileSizeLow        As Long
    dwReserved0         As Long
    dwReserved1         As Long
    cFileName           As String * MAX_PATH
    cAlternate          As String * 14
End Type

Private Const FIND_FIRST_EX_CASE_SENSITIVE  As Long = 1
'MSDN: "This value is not supported until Windows Server 2008 R2 and Windows 7."
Private Const FIND_FIRST_EX_LARGE_FETCH     As Long = 2

Private Enum FINDEX_SEARCH_OPS
    FindExSearchNameMatch
    FindExSearchLimitToDirectories
    FindExSearchLimitToDevices
End Enum

Private Enum FINDEX_INFO_LEVELS
    FindExInfoStandard
    FindExInfoBasic 'MSDN: "This value is not supported until Windows Server 2008 R2 and Windows 7."
    FindExInfoMaxInfoLevel
End Enum

Private Declare Function FindFirstFileEx Lib "kernel32" Alias "FindFirstFileExA" ( _
ByVal lpFileName As String, ByVal fInfoLevelId As Long, lpFindFileData As WIN32_FIND_DATA, _
    ByVal fSearchOp As Long, ByVal lpSearchFilter As Long, ByVal dwAdditionalFlags As Long) As Long
Private Declare Function FindNextFile Lib "kernel32" Alias "FindNextFileA" ( _
    ByVal hFindFile As Long, lpFindFileData As WIN32_FIND_DATA) As Long
Private Declare Function FindClose Lib "kernel32" (ByVal hFindFile As Long) As Long


Private Function GetFiles(ByVal sPath As String) As Collection

    Dim fileInfo    As WIN32_FIND_DATA  'buffer for file info
    Dim hFile       As Long             'file handle
    Dim colFiles    As New Collection

    sPath = sPath & "*.*"

    hFile = FindFirstFileEx(sPath & vbNullChar, FindExInfoBasic, fileInfo, FindExSearchNameMatch, 0&, FIND_FIRST_EX_LARGE_FETCH)

    If hFile <> INVALID_HANDLE_VALUE Then
        Do While FindNextFile(hFile, fileInfo)
            colFiles.Add Left(fileInfo.cFileName, InStr(fileInfo.cFileName, vbNullChar) - 1)
        Loop

        FindClose hFile
    End If

    Set GetFiles = colFiles

End Function

Answer 2

I thought that there would be an API which could get me the file names in a directory without looping but couldn't find it. All the code that I know of involves looping either using fso or dir.

So is it possible to get the file names without looping. I guess yes... Here is one way I can think of...

When you type the below command in DOS Prompt, the entire file structure is sent to a text file

Dir C:\Temp\*.* > C:\Temp\MyFile.Txt

Doing the above from VBA

Sub Sample()
    Dim sPath As String

    sPath = "C:\Temp\"

    '~~> DIR C:\Temp\*.* > C:\Temp\MyFile.txt
    retval = Shell("cmd.exe /c Dir " & sPath & "*.* > " & sPath & "MyFile.Txt")
End Sub

For example (This is what is stored in MyFile.Txt)

Volume in drive C is XXXXXXX
Volume Serial Number is XXXXXXXXX

Directory of C:\Temp

10/08/2014  11:28 PM    <DIR>          .
10/08/2014  11:28 PM    <DIR>          ..
10/08/2014  11:27 PM               832 aaa.txt
10/08/2014  11:28 PM                 0 bbb.txt
10/08/2014  11:26 PM                 0 New Bitmap Image.bmp
10/08/2014  11:26 PM                 0 New Bitmap Image_2.bmp
10/08/2014  11:26 PM                 0 New Bitmap Image_2_2.bmp
10/08/2014  11:26 PM                 0 New Bitmap Image_3.bmp
10/08/2014  11:26 PM                 0 New Bitmap Image_3_2.bmp
10/08/2014  11:26 PM                 0 New Bitmap Image_4.bmp
10/08/2014  11:26 PM                 0 New Bitmap Image_4_2.bmp
10/08/2014  11:26 PM                 0 New Bitmap Image_5.bmp
            10 File(s)            832 bytes
             2 Dir(s)  424,786,952,192 bytes free

So now all you need to do is copy the text file from the remote folder to your folder and simply parse it to get the file names.

Answer 3

This one is lightning fast:

  Sub filesTest()
    Dim x() As String
    x = Function_FileList("YOUR_PATH_AND_FOLDER_NAME")
    Debug.Print Join(x, vbCrLf)
  End Sub

Which calls this function:

 Function Function_FileList(FolderLocation As String)
    Function_FileList = Filter(Split(CreateObject("wscript.shell").exec("cmd /c Dir """ & FolderLocation & """ /b /a-d").stdout.readall, vbCrLf), ".")
 End Function