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checksum on a file in Windows

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Wayne Johnston

checksum on a file in Windows

I can't seem to find an existing way to find the checksum on a file in Windows (preferably via a primitive so it's efficient). A way to do it doesn't even seem to be built into Windows as far as I can tell. I'd like to do this without having to require new software on all of our client machines. Ideas?

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SebastianHC

Re: checksum on a file in Windows

Hi Wayne,

I can only point you on this article.
http://www.codeguru.com/cpp/cpp/algorithms/checksum/article.php/c5103/CRC32-Generating-a-checksum-for-a-file.htm
You should be able to reimplement this in VAST or just bind it.

I already mapped filea into memory with VAST. It works but as far as I
can remember I had to bind some further windows api functions, or define
further constants in the pools. Ican't remember right now.

A good startingpoint could also be:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms680355(v=vs.85).aspx

Good luck!
Sebastian

Am 09.07.2013 07:36, schrieb Wayne Johnston:

> I can't seem to find an existing way to find the checksum on a file in
> Windows (preferably via a primitive so it's efficient). A way to do
> it doesn't even seem to be built into Windows as far as I can tell.
> I'd like to do this without having to require new software on all of
> our client machines. Ideas? --
> You received this message because you are subscribed to the Google
> Groups "VA Smalltalk" group.
> To unsubscribe from this group and stop receiving emails from it, send
> an email to [hidden email].
> To post to this group, send email to [hidden email].
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Marten Feldtmann-2

Re: checksum on a file in Windows

When thinking about crc32 (or as an alternative: adler) you should always consider zip/unzip libraries.

Since VA8.52 Instantiations has support for this. Look at:

MZDllCall>>crc32:buffer:length:

or

MSDllCall>>adler:buffer:length:

and when you notice the c example in the method you might implement this loop in Smalltalk and use this low level c call.

Marten

Am Dienstag, 9. Juli 2013 21:06:42 UTC+2 schrieb Sebastian Heidbrink:

Hi Wayne,

I can only point you on this article.
http://www.codeguru.com/cpp/cpp/algorithms/checksum/article.php/c5103/CRC32-Generating-a-checksum-for-a-file.htm
You should be able to reimplement this in VAST or just bind it.

I already mapped filea into memory with VAST. It works but as far as I
can remember I had to bind some further windows api functions, or define
further constants in the pools. Ican't remember right now.

A good startingpoint could also be:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms680355(v=vs.85).aspx

Good luck!
Sebastian

Am 09.07.2013 07:36, schrieb Wayne Johnston:

> I can't seem to find an existing way to find the checksum on a file in
> Windows (preferably via a primitive so it's efficient). A way to do
> it doesn't even seem to be built into Windows as far as I can tell.
> I'd like to do this without having to require new software on all of
> our client machines. Ideas? --
> You received this message because you are subscribed to the Google
> Groups "VA Smalltalk" group.
> To unsubscribe from this group and stop receiving emails from it, send
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