GetDiskFreeSpaceEx
The GetDiskFreeSpaceEx function retrieves information about the amount of space available on a disk
volume: the total amount of space, the total amount of free space, and the total amount of free space available
to the user associated with the calling thread.
BOOL GetDiskFreeSpaceEx(
LPCTSTR lpDirectoryName,
PULARGE_INTEGER lpFreeBytesAvailable,
PULARGE_INTEGER lpTotalNumberOfBytes,
PULARGE_INTEGER lpTotalNumberOfFreeBytes
);
Parameters
lpDirectoryName
[in] Pointer to a null-terminated string that specifies a directory on the disk of interest. If this parameter is
NULL, the function uses the root of the current disk. If this parameter is a UNC name, it must include a
trailing backslash (for example, \\MyServer\MyShare\).
Note that this parameter does not have to specify the root directory on a disk. The function accepts any
directory on the disk.
lpFreeBytesAvailable
[out] Pointer to a variable that receives the total number of free bytes on the disk that are available to the
user associated with the calling thread. This parameter can be NULL.
If per-user quotas are in use, this value may be less than the total number of free bytes on the disk.
lpTotalNumberOfBytes
[out] Pointer to a variable that receives the total number of bytes on the disk that are available to the user
associated with the calling thread. This parameter can be NULL.
If per-user quotas are in use, this value may be less than the total number of bytes on the disk.
lpTotalNumberOfFreeBytes
[out] Pointer to a variable that receives the total number of free bytes on the disk. This parameter can be
NULL.
Return Values
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
Remarks
Note that the values obtained by this function are of type ULARGE_INTEGER. Be careful not to truncate these
values to 32 bits.
Windows 95 OSR2 and later: The GetDiskFreeSpaceEx function is available beginning with Windows 95
OEM Service Release 2 (OSR2). To determine whether GetDiskFreeSpaceEx is available, call
GetModuleHandle to get the handle to Kernel32.dll. Then you can call GetProcAddress.
The following code fragment shows one way to do this:
pGetDiskFreeSpaceEx = GetProcAddress( GetModuleHandle("kernel32.dll"),
"GetDiskFreeSpaceExA");
if (pGetDiskFreeSpaceEx)
{
fResult = pGetDiskFreeSpaceEx (pszDrive,
(PULARGE_INTEGER)&i64FreeBytesToCaller,
(PULARGE_INTEGER)&i64TotalBytes,
(PULARGE_INTEGER)&i64FreeBytes);
// Process GetDiskFreeSpaceEx results.
}
else
{
fResult = GetDiskFreeSpace (pszDrive,
&dwSectPerClust,
&dwBytesPerSect,
&dwFreeClusters,
&dwTotalClusters)
// Process GetDiskFreeSpace results.
Platform SDK: Storage
}
It is not necessary to call LoadLibrary on Kernel32.dll because it is already loaded into every process address
space.
Windows NT Server 3.51 and earlier, Windows 95: Include an additional header file called NewAPIs.h to
make GetDiskFreeSpaceEx available on these operating systems. The function is not implemented natively,
but by a wrapper that utilizes other native functions on these systems. See the header file for details of the use
of preprocessor directives that make the function available. If you do not have this header file, it can be
obtained by downloading the most recent Windows SDK from the SDK Update Site.
Windows Me/98/95 OSR2: GetDiskFreeSpaceExW is supported by the Microsoft Layer for Unicode. To use
this, you must add certain files to your application, as outlined in Microsoft Layer for Unicode on
Windows 95/98/Me Systems.
Requirements
Client: Included in Windows XP, Windows 2000 Professional, Windows NT Workstation 4.0, Windows Me,
Windows 98, and Windows 95 OSR2 and later.
Server: Included in Windows Server 2003, Windows 2000 Server, and Windows NT Server 4.0.
Unicode: Implemented as Unicode and ANSI versions. Note that Unicode support on Windows Me/98/95
requires Microsoft Layer for Unicode.
Header: Declared in Winbase.h; include Windows.h.
Library: Use Kernel32.lib.
See Also
Disk Management Functions, GetDiskFreeSpace,, GetModuleHandle, GetProcAddress
Platform SDK Release: February 2003
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