How to get the allocated file size?

[blindwig]

Does AutoIt have a funciton to get the allocated file size?

I know that FileGetSize will return the actual size of the file, but say I have a 5k file on a filesystem using 4k blocks. Obviously the file has 8k allocated for it. Is there a built-in function to tell me this?

[jpm]

Does AutoIt have a funciton to get the allocated file size?

I know that FileGetSize will return the actual size of the file, but say I have a 5k file on a filesystem using 4k blocks.  Obviously the file has 8k allocated for it.  Is there a built-in function to tell me this?

<{POST_SNAPBACK}>

no that I know about :">

[blindwig]

Is that hard to do in C++? I mean, would it be easy for the devs to add a built-in function (or a flag to the original FileGetSize() function) or should I figure out a way to do it through a DLL call?

[/dev/null]

Is that hard to do in C++?  I mean, would it be easy for the devs to add a built-in function (or a flag to the original FileGetSize() function) or should I figure out a way to do it through a DLL call?

I doubt there is a user mode API call for this in Windows. However, I'm happy if you find one.

Cheers

Kurt

[Valik]

I doubt there is a user mode API call for this in Windows. However, I'm happy if you find one.

Cheers

Kurt

<{POST_SNAPBACK}>

I took a look and I didn't spot a function that jumped out sand said, "Hey, look-it-me, I'm the one you want". I would first try Google and see if there is anything about it there. If not, then the best I can think of is to find out the block-size for the drive the file is located on and then find the next multiple of the drive size that is larger than the current file size. Do all that programmatically, of course. I'm afraid I don't know of any API function off the top of my head that gives the partition block size, though.

[blindwig]

I assume that it's built into windows somewhere, because if you view a file's properties in Windows Explorer there is a text that says "Size on Disk". on my system I'm noticing that it's always a multiple of 4K, which makes sense since my HD is formatted NTFS with 4K blocks.

And I could have sworn that DIR used to have an undocumented switch to return allocated size instead of actual size, but I can't find any info on it.

Hmm... OK, so does anyone know how to determine the block-size of a file system from a given file name?

[/dev/null]

current file size.  Do all that programmatically, of course.  I'm afraid I don't know of any API function off the top of my head that gives the partition block size, though.

<{POST_SNAPBACK}>

Not an API call, but WMI Class Win32_Volume can do it (Parameter: Blocksize).

Cheers

Kurt

[GaryFrost]

Not an API call, but WMI Class Win32_Volume can do it (Parameter: Blocksize).

Cheers

Kurt

<{POST_SNAPBACK}>

Windows XP and earlier: This class is not available

[/dev/null]

Windows XP and earlier:  This class is not available

<{POST_SNAPBACK}>

Ups.. you're right, requires Windows Server 2003. Sorry, then I don't know a way how to do it.

Cheers

Kurt

[Lazycat]

What is I have found, try this code (need beta of course):

$pGDFS = DllStructCreate("dword;dword;dword;dword")

$ret = DllCall("kernel32.dll","int","GetDiskFreeSpace",_
                    "str", "C:\",_
                    "ptr",DllStructGetPtr($pGDFS,1),_
                    "ptr",DllStructGetPtr($pGDFS,2),_
                    "ptr",DllStructGetPtr($pGDFS,3),_
                    "ptr",DllStructGetPtr($pGDFS,4))

$res = DllStructGetData($pGDFS, 1) * DllStructGetData($pGDFS, 2)
DllStructDelete($pGDFS)
MsgBox (0, "Cluster Size", $res)

Tested only under XP, but this should works on earlier versions.

[blindwig]

Sweet - I tried it here on XP pro and it works - even for network drives!

Thanks!

[w0uter]

something like this ?

Func _FileGetRealSize($s_path)
    
If Not FileExists($s_path) Then
    SetError(1)
    Return 0
EndIf
    
Local $s_drive = StringLeft($s_path, 3)
    
If StringLeft($s_path, 1) = '.' Then $s_drive = StringLeft(@ScriptDir, 3)
If StringLeft($s_path, 2) = '\\' Then $s_drive = StringLeft($s_path, StringInStr($s_path, '\', 0, 3)
    
ConsoleWrite($s_drive & @LF)
    
$v_struct = DllStructCreate("dword;dword;dword;dword")

$ai_ret = DllCall("kernel32.dll","int","GetDiskFreeSpace",_
                    "str", $s_drive,_
                    "ptr",DllStructGetPtr($v_struct,1),_
                    "ptr",DllStructGetPtr($v_struct,2),_
                    "ptr",DllStructGetPtr($v_struct,3),_
                    "ptr",DllStructGetPtr($v_struct,4))

$i_res = DllStructGetData($v_struct, 1) * DllStructGetData($v_struct, 2)
DllStructDelete($v_struct)

$i_size = FileGetSize($s_path)
$i_size = Ceiling($i_size/$i_res)*$i_res

Return $i_size

EndFunc

[Jon]

Sweet - I tried it here on XP pro and it works - even for network drives!

Thanks!

Out of morbid curiousity is that a real gonk or an clip-art gonk?

Gonks are are biggest unheard anti-desktop rollout agent of the 21st century

[blindwig]

Out of morbid curiousity is that a real gonk or an clip-art gonk?

uhhh... Gonk? Do you mean my Avatar? It's a picture of a stress ball I have on my desk at work. My girlfriend gave it to me last Christmas and it's already pretty worn - you can see the tounge is starting to peel off and the eyes are cracking. I took it on my cell phone and blue-toothed it to my laptop (my main computer at work) and scaled it and uploaded it here.

Gonks are are biggest unheard anti-desktop rollout agent of the 21st century

uhhh... you really lost me there. Please rephrase?

[blindwig]

something like this ?

Yeah, looks good.

There was a missing ) on line 11, and you need to include math.au3 and use _Ceil(), but other than that it works.

Oh, and you need to change the StringInStr line to find the 4th occurance of '\' instead of the 3rd, because '\\127.0.0.1\' is not a drive, but '\\127.0.0.1\c-drive\' is.

And I didn't realize this, but _Ceil() returns 1 when given a 0, so this even works on 0k files (which should have 1 cluster allocated to them)

Cool.

[Valik]

And I didn't realize this, but _Ceil() returns 1 when given a 0, so this even works on 0k files (which should have 1 cluster allocated to them)

Cool.

On (at least NTFS), a 0-byte file is only stored in the MFT. There is no actual hard disk space used and the file will be 0 bytes until the first character is added, then it will obtain disk space to be stored.

[w0uter]

@blindwig

why use _ceil ? ceiling is better.

[CyberSlug]

So how many 0-byte files can you fit on a hard drive before it fills up?

[herewasplato]

uhhh...  Gonk?  Do you mean my Avatar?...

<{POST_SNAPBACK}>

Not to speak for Jon, but I googled "gonk" when I saw his post last night.

Toward the bottom of this page are some pictures of what someone else calls a gonk: http://www.twingo.net/twungi.html

Perhaps the little character added to what appears to be an album or CD cover is also a gonk: http://www.geocities.com/philippesmash/gonkspic.jpg

It must mean something on the other side of the pond.....

edit typo

Edited July 22, 2005 by herewasplato

[Valik]

So how many 0-byte files can you fit on a hard drive before it fills up?

<{POST_SNAPBACK}>

Well, technically speaking, they do take up something because at least the name/location is stored in the Master File Table. So assuming you wished to take the time, I suppose it's theoretically possible that you could create enough 0 byte files to fill the MFT causing it to expand and expand until it used up the entire hard drive. However, I would suspect that it is not possible for the MFT to do that, there is surely a cap on its growth size. Also, I would argue that the 0 byte files are not what is filling the hard drive up but rather the information being used to record their existence. So I would say that you could fit as many files as you had: BytesFreeSpace / SizeOfFileEntryInMFT = NumberOfZeroByteFiles.

I'm intrigued by this...