Other Compound File Advantages

You've seen how compound files add a kind of random access capability to your programs, and you can appreciate the value of transactioning. Now consider the brave new world in which every program can read any other program's documents. We're not there yet, but we have a start. Compound files from Microsoft applications have a stream under the root storage named \005SummaryInformation. This stream is formatted as a property set, as defined for ActiveX controls. If you can decode the format for this stream, you can open any conforming file and read the summary.

Visual C++ comes with a compound file viewing utility named DocFile Viewer (Dfview.exe), which uses a tree view to display the file's storages and streams. Here is the DocFile Viewer output for the structured storage file generated by EX27A.

As a matter of fact, you can use DFVIEW to view the structure of any compound file. Are you starting to see the potential of this "universal file format?"