Games in `.dosz` archives not recognized

[fekir]

After opening an issue schellingb/dosbox-pure#690, I believe that at least one issue does not depend on the core, I hope this is the right place to report it.

I have a DOS game, and stored the whole disk content in a dedicated directory.
I also archived the directory in a zip archive, and copied the .zip archive to a .dosz file, as described here: https://docs.libretro.com/library/dosbox_pure/#zip-files-can-be-renamed-to-dosz

This is what I've observed so far after enabling in RetroArch the dosbox-pure core.

In RetroArch I've used the "import content -> scan directory" functionality for creating a DOS playlist:

• start.exe in the folder is found and recognized
• start.exe in .zip is found and recognized
• start.exe in .dosz is not found

The expected behavior would be that games archived as .dosz are recognized, since this format is supported by the core.

[zoltanvb]

The DOS database contains .com, .exe, and .bat entries, so the .dosz files will not match the CRC. During scanning, recognized archive files are opened and contents are checked, but .dosz is not recognized as an archive file.

It is probably not impossible to add .dosz check to the scan logic, and have the scanner add the .dosz file itself instead of the usual archive#something.exe path to keep the original intent, but it would be quite a custom fit for this core only.

[fekir]

Yes, I was hoping that adding support would not be too cumbersome.

The file format is the same as zip files, so during scanning, "just" handle dosz as zip archives.

For the playlist, "just" store the path to the dosz file instead of the exe/com/bat inside the archive.

[RobLoach]

Is there a CRC database of .dosz files we could index?

[fekir]

I do not think such database exist.

Plus, since .dosz files are just renamed .zip archives, and since zip archives with a fixed content, can have different crc values, for example because

• files in zip have different timestamps
• files listed in zip archive ca have different order
• file can have different compression levels

I do not think it would make much sense to create such database.

Plus wouldn't it be a duplicate of the existing dos database?

[RobLoach]

Makes sense... Would it be a thing where we just scan inside the .dosz files as .zip files?

[fekir]

Makes sense... Would it be a thing where we just scan inside the .dosz files as .zip files?

If the question is directed at me: I guess so.

From a "high"-level perspective, I would have proposed to

• handle .dosz files as zip archives during the scanning process
• when creating the playlist file, instead of storing the path to the exec/com/bat file inside the .dosz archive, just store the path to the .dosz archive

This would make it possible to reuse existing databases.