>>>How do I get the correct cluster size for a disk?
>>>
>>>The built-in command in VFP, sys(2022), always returns 32KB for networked drives, but also for FAT32 drives, even if they are local.
>>>
>>>Hilmar.
>>
>>The GetDiskFreeSpace() API call used to correctly return this information. However, with the advent of disks greater than 2 gb, it is not reliable since it caps the amount of space at 2 gb, adjusting the values returned accordingly. In short, this sort of information cannot be reliably returned even from the API.

Hilmar,

>No, no, 'tis not the free space I want, but the cluster size.

I know. GetDiskFreeSpace() returns the bytes per sector and the sectors per cluster, in addition to other information.

>I wrote a small utility, which I called "Who's gobbling my hard disk", that totals file sizes for each folder. For accurate information, for a specific disk, I need the cluster size. For instance, on my current "C:" drive, a 100-byte batch-file actually uses 4 KB, because that is the cluster size I am using.
>
>Since sys(2022) isn't trustworthy (see my original message), I gave the user the option of selecting the cluster size.

How?

>This I will do anyway, even if I find out how to get the cluster size: it may be useful to know how much space would be used somewhere else. For instance, if I copy files to a ZIP disk (cluster size: 2 KB, I believe).
>
The only reliable way to do it across all Win32 platform and file systems is to write get the amount of free space, write a small temporary file, and get the amount of free space afterwards.

FWIW, here's the GetDiskFreeSpace() syntax:

DECLARE INTEGER GetDiskFreeSpace IN Win32API;
  STRING @lpRootPathName, INTEGER @lpSectorsPerCluster,;
  INTEGER @lpBytesPerSector, INTEGER @lpNumberOfFreeClusters,;
  INTEGER @lpTotalNumberOfClusters
lcpath = "C:\"
STORE 0 TO lnsectors, lnbytes, lnfree, lntotal
? GetDiskFreeSpace(@lcpath, @lnsectors, @lnbytes, @lnfree, @lntotal)
? lnsectors * lnbytes && Cluster size

On a Win2K box it accurately reports a 4K cluster size. On a Win98SE box, it reports 32K, when in reality the cluster size is 4K.