physical file size

hi all,

As we know, a file has two sizes, logical size and physical size. When we
right-click properties on some file, the two can be seen separately as
"Size" and "Size On Disk".

I'd like to know how i can programatically obtain the physcial file size of
one remote file that locates in some windows NTFS share folder.

I know that fsutil tool can get the block/cluster size on one local volume
but doesn't work on remote volumes.

Is there some way able to get the physical file size directly for NTFS
files? Any ideas?

For nfs files, it seems that it can be done easily by obtaining the file
attributes.

Thanks a lot

Robert