GetLogicalDriveStrings
The GetLogicalDriveStrings function fills a buffer with strings that specify valid drives in the system.
DWORD GetLogicalDriveStrings(
DWORD nBufferLength, // size of buffer
LPTSTR lpBuffer // pointer to buffer for drive strings
);
Parameters
nBufferLength
Specifies the maximum size, in characters, of the buffer pointed to by lpBuffer. This size does not include the terminating null character.
lpBuffer
Pointer to a buffer that receives a series of null-terminated strings, one for each valid drive in the system, that end with a second null character. The following example shows the buffer contents with <null> representing the terminating null character.
c:\<null>d:\<null><null>
Return Values
If the function succeeds, the return value is the length, in characters, of the strings copied to the buffer, not including the terminating null character. Note that an ANSI-ASCII null character uses one byte, but a Unicode null character uses two bytes.
If the buffer is not large enough, the return value is greater than nBufferLength. It is the size of the buffer required to hold the drive strings.
If the function fails, the return value is zero. To get extended error information, use the GetLastError function.
Remarks
Each string in the buffer may be used wherever a root directory is required, such as for the GetDriveType and GetDiskFreeSpace functions.
QuickInfo
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in winbase.h.
Import Library: Use kernel32.lib.
Unicode: Implemented as Unicode and ANSI versions on Windows NT.
See Also
File I/O Overview, File Functions, GetDriveType, GetDiskFreeSpace, GetLogicalDrives
GetDiskFreeSpace
The GetDiskFreeSpace function retrieves information about the specified disk, including the amount of free space on the disk.
This function has been superseded by the GetDiskFreeSpaceEx function. New Win32-based applications should use GetDiskFreeSpaceEx.
BOOL GetDiskFreeSpace(
LPCTSTR lpRootPathName, // pointer to root path
LPDWORD lpSectorsPerCluster, // pointer to sectors per cluster
LPDWORD lpBytesPerSector, // pointer to bytes per sector
LPDWORD lpNumberOfFreeClusters,
// pointer to number of free clusters
LPDWORD lpTotalNumberOfClusters
// pointer to total number of clusters
);
Parameters
lpRootPathName
Pointer to a null-terminated string that specifies the root directory of the disk to return information about. If lpRootPathName is NULL, the function uses the root of the current directory. If this parameter is a UNC name, you must follow it with an additional backslash. For example, you would specify \\MyServer\MyShare as \\MyServer\MyShare\.
Windows 95: The initial release of Windows 95 does not support UNC paths for the lpszRootPathName parameter. To query the free disk space using a UNC path, temporarily map the UNC path to a drive letter, query the free disk space on the drive, then remove the temporary mapping. Windows 95 OSR2 and later: UNC paths are supported.
lpSectorsPerCluster
Pointer to a variable for the number of sectors per cluster.
lpBytesPerSector
Pointer to a variable for the number of bytes per sector.
lpNumberOfFreeClusters
Pointer to a variable for the total number of free clusters on the disk that are available to the user associated with the calling thread.
Windows NT 5.0 and later: If per-user disk quotas are in use, this value may be less than the total number of free clusters on the disk.
lpTotalNumberOfClusters
Pointer to a variable for the total number of clusters on the disk that are available to the user associated with the calling thread.
Windows NT 5.0 and later: If per-user disk quotas are in use, this value may be less than the total number of clusters on the disk.
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
The GetDiskFreeSpaceEx function lets you avoid the arithmetic required by the GetDiskFreeSpace function.
Windows 95:
The GetDiskFreeSpace function returns incorrect values for volumes that are larger than 2 gigabytes. The function caps the values stored into *lpNumberOfFreeClusters and *lpTotalNumberOfClusters so as to never report volume sizes that are greater than 2 gigabytes.
Even on volumes that are smaller than 2 gigabytes, the values stored into *lpSectorsPerCluster, *lpNumberOfFreeClusters, and *lpTotalNumberOfClusters values may be incorrect. That is because the operating system manipulates the values so that computations with them yield the correct volume size.
Windows 95 OSR2 and later:
The GetDiskFreeSpaceEx function is available on Windows 95 systems beginning with OEM Service Release 2 (OSR2). The GetDiskFreeSpaceEx function returns correct values for all volumes, including those that are greater than 2 gigabytes.
QuickInfo
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in winbase.h.
Import Library: Use kernel32.lib.
Unicode: Implemented as Unicode and ANSI versions on Windows NT.
See Also
File I/O Overview, File Functions, GetDiskFreeSpaceEx, GetDriveType
