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  • Thread starter Thread starter Frank Pospischil
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Frank Pospischil

Hi there,

can somebody please explain the following:

When i open an existing ppt and exit the application without changing
anything, the file keeps its original date and timestamp.
Good, this can be expected, because i assume that the file wasn´t changed in
any way.
This is true when i was the last person who accessed the file. When some
other user does the same thing afterwards (open and exit without changes ),
the timestamp also stays the same although a binary compare with a
previously made copy shows differences !
Every time, the file is "viewed" by a different user, the content changes.
Regardless of this, the developers did some magic to make the file look like
not beeing touched.
What exactly is happening ?
This behavior leads to problems, when the file is not stored on a Windows
machine !!
Non-MS filesystems obviously detect the change and reflect it by changing
the timestamp. This results in "brand new edited" old Documents when they
are only viewed.

What´s the magic ? What is it good for ?
When i say "do nothing !" i wold expect the application to do nothing !

Please light up my mind.
Thanks in advance

Frank
 
I should clarify.... PPS is exempt unless opened thru PowerPoint in edit
view.

I don't know how 'fast saves' would affect the files either. If changes are
not made, does it still balloon the file size? The 'Revisions' property is
also modified with each manual change.

One possibility would be to automate PowerPoint thru VB and create a
directory of exported JPG images of all the slides and compare a previously
exported series of images. This would not tell you if the animations,
transitions or off screen content were changed, but would flag most changes.

Another possible answer may lay in the exact size of the file (rather than
the modified date).

B
 
Hi B,

interesting details. Do you know anything about the mechanism that replaces
the original file after it has been locked,copied for editing and then
stored with the original "file attributes" ? does it rely on "File system
tunneling capabilities" as described in KB 172190 ?
First testing on a system with this "feature" disabled do not lead to
changed timestamps ...
How rsp. where are the original file-infos stored that are then restored
(when "almost nothing" was changed). And what might be the reason for succes
on Win and different behaviour on non NTFS filesystems ?

Thanks for your support.

Frank
 
Sorry Frank. No, I don't know.

I'd assume the time in edit is in a header of some sort that is
intentionally overlooked by Win. But it sounds as if you are much father
along this knowledge path than I am.

B
 
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