Properly reading the EDITTIME structure in an OLE Structured Storage file (ie just about any Office Document)

Filed under Uncategorized

There’s lots of articles out there about reading the properties of an OLE Structured Storage file (which is the format used for all Office apps before 2007 and with continued support in Office 2007).

Eduardo Morcillo probably has about the best implementation for VB6 that I’ve come across. Check here for tons of great VB6 code for opening/reading structured storage files, and lots of other very advanced stuff.

.NET likely makes much of this dramatically easier, but I haven’t delved into that yet so I can’t say for sure.

What I do know, however, is that Eduardo’s code doesn’t quite handle a few elements of OLE document properties. One in particular is the EDITTIME property.

EDITTIME normally tracks how long a particular file has been “edited” within a given application, be it Word, Excel, or PowerPoint.

The field itself is stored as a 64bit FILETIME structure, but it’s not actually a FILETIME structure. Instead, the EDITTIME is stored as a direct 64bit number of milliseconds that the document has been edited.

Check out here for all the details, and a good sampling of some C code to convert the EDITTIME element to a number of seconds and back again.

It’s not terribly difficult code, but it’s also virtually undocumented as to the layout of that structure.

I won’t repeat the code here, but I have to give credit to Rolandas Rudomanskis and the Shareaza team for researching the issue and making the code available.

Post a Comment

Your email is never published nor shared. Required fields are marked *