File size

[FeepingCreature]

On Monday, 21 August 2023 at 07:52:28 UTC, harakim wrote:
> I have been doing some backups and I wrote a utility that 
> determines if files are an exact match. As a shortcut, I check 
> the file size. So far so good on this with millions of files 
> until I found something odd: getSize() and DirEntry's .size are 
> producing different values.
> 
> ...
> 
> It seems really odd that getSize(sourceFile.name) is returning 
> a different number than sourceFile.size. This is an external 
> HDD on windows formatted in ntfs that it is reading. I believe 
> I originally wrote the files to the file system in Windows, but 
> then today I cut and paste them (in the same drive) in Linux. 
> However, this is the first time this has happened after 
> millions of comparisons and it only happened for about 6 files. 
> It does happen consistently though.
>
> I have verified that the file size is that reported by getSize 
> and not sourceFile.size and that the files open correctly.
>
> ...

Can you print some of the wrong sizes? D's DirEntry iteration 
code just calls `FindFirstFileW`/`FindNextFileW`, so this 
*shouldn't* be a D-specific issue, and it should be possible to 
reproduce this in C.