GetFreeSpace

Public Type ULong ' Unsigned Long
    Byte1 As Byte
    Byte2 As Byte
    Byte3 As Byte
    Byte4 As Byte
End Type

Public Type LargeInt ' Large Integer
    LoDWord As ULong
    HiDWord As ULong
    LoDWord2 As ULong
    HiDWord2 As ULong
End Type

Public Declare Function GetDiskFreeSpaceEx Lib "kernel32" _
       Alias "GetDiskFreeSpaceExA" _
       (ByVal lpRootPathName As String, _
       FreeBytesAvailableToCaller As LargeInt, _
       TotalNumberOfBytes As LargeInt, _
       TotalNumberOfFreeBytes As LargeInt) As Long

Function GetFreeSpace(strPath as String) As Double
  Dim nFreeBytesToCaller As LargeInt
  Dim nTotalBytes As LargeInt
  Dim nTotalFreeBytes As LargeInt
  strPath = Trim(strPath)

If Right(strPath, 1) <> "\" Then
     strPath = strPath & "\"
  End If

If GetDiskFreeSpaceEx(strPath, nFreeBytesToCaller, _
     nTotalBytes, nTotalFreeBytes) <> 0 Then
     GetFreeSpace = CULong( _
     nFreeBytesToCaller.HiDWord.Byte1, _
     nFreeBytesToCaller.HiDWord.Byte2, _
     nFreeBytesToCaller.HiDWord.Byte3, _
     nFreeBytesToCaller.HiDWord.Byte4) * 2 ^ 32 + _
     CULong(nFreeBytesToCaller.LoDWord.Byte1, _
     nFreeBytesToCaller.LoDWord.Byte2, _
     nFreeBytesToCaller.LoDWord.Byte3, _
     nFreeBytesToCaller.LoDWord.Byte4)
  End If

End Function

Function CULong(Byte1 As Byte, Byte2 As Byte, _
         Byte3 As Byte, Byte4 As Byte) As Double
  CULong = Byte4 * 2 ^ 24 + Byte3 * 2 ^ 16 + Byte2 * 2 ^ 8 + Byte1
End Function
 Inputs:
Pass any valid path to the GetFreeSpace function. 
The path could be a local drive ("c:" or "c:\windows"), 
network drive ("x:" or "x:\MyFolder") or UNC path like 
"\\myserver\myshare".

Returns:
GetFreeSpace function returns total number of free bytes 
on the disk that are available to the user associated

with the calling thread. Return value isa Double.

Assumes:
Under Windows 2000: if per-userquotas are in use, the 
value returned by GetFreeSpace function may be less than 
the total number of free bytes on the disk. 
This code can be modified To Get total number of free bytes 
on the disk (without regard to the user quota) or total 
number of bytes on the disk.

Side Effects:
This code will not work on versions of Windows 95 prior 
to OSR2.

Public Type ULong ' Unsigned Long
Byte1 As Byte
Byte2 As Byte
Byte3 As Byte
Byte4 As Byte
End Type

Public Type LargeInt ' Large Integer
LoDWord As ULong
HiDWord As ULong
LoDWord2 As ULong
HiDWord2 As ULong
End Type

Public Declare Function GetDiskFreeSpaceEx Lib "kernel32" _
Alias "GetDiskFreeSpaceExA" _
(ByVal lpRootPathName As String, _
FreeBytesAvailableToCaller As LargeInt, _
TotalNumberOfBytes As LargeInt, _
TotalNumberOfFreeBytes As LargeInt) As Long

Function GetFreeSpace(strPath as String) As Double
Dim nFreeBytesToCaller As LargeInt
Dim nTotalBytes As LargeInt
Dim nTotalFreeBytes As LargeInt
strPath = Trim(strPath)

If Right(strPath, 1) <> "\" Then
strPath = strPath & "\"
End If

If GetDiskFreeSpaceEx(strPath, nFreeBytesToCaller, _
nTotalBytes, nTotalFreeBytes) <> 0 Then
GetFreeSpace = CULong( _
nFreeBytesToCaller.HiDWord.Byte1, _
nFreeBytesToCaller.HiDWord.Byte2, _
nFreeBytesToCaller.HiDWord.Byte3, _
nFreeBytesToCaller.HiDWord.Byte4) * 2 ^ 32 + _
CULong(nFreeBytesToCaller.LoDWord.Byte1, _
nFreeBytesToCaller.LoDWord.Byte2, _
nFreeBytesToCaller.LoDWord.Byte3, _
nFreeBytesToCaller.LoDWord.Byte4)
End If

End Function

Function CULong(Byte1 As Byte, Byte2 As Byte, _
Byte3 As Byte, Byte4 As Byte) As Double
CULong = Byte4 * 2 ^ 24 + Byte3 * 2 ^ 16 + Byte2 * 2 ^ 8 + Byte1
End Function
Inputs:
Pass any valid path to the GetFreeSpace function.
The path could be a local drive ("c:" or "c:\windows"),
network drive ("x:" or "x:\MyFolder") or UNC path like
"\\myserver\myshare".

Returns:
GetFreeSpace function returns total number of free bytes
on the disk that are available to the user associated

with the calling thread. Return value isa Double.

Assumes:
Under Windows 2000: if per-userquotas are in use, the
value returned by GetFreeSpace function may be less than
the total number of free bytes on the disk.
This code can be modified To Get total number of free bytes
on the disk (without regard to the user quota) or total
number of bytes on the disk.

Side Effects:
This code will not work on versions of Windows 95 prior
to OSR2.