Adding EPUBs/PDFs back to Calibre Library

[eBookWorm21]

I think I may have shot myself in the foot, so to speak, by removing the EPUBs from my Calibre Library to Apple Books, and then deleting them from my Calibre Library. I realized afterwards, with 20/20 hindsight, that there were other files in the ebook's Calibre Library folder that it created when I originally added them the the Library.

Calibre has some features that Apple Books doesn't have, so I'd like to copy my ebooks back to Calibre. I have a full copy of my library on an external hard drive. I'm running macOS Ventura 13 and Calibre 6.8.0, which seems to be the most current version.

I am getting errors like this when I add some of the EPUBs back to Calibre:

calibre, version 6.8.0
WARNING: Errors while adding: There were problems adding some files, click "Show details" for more information
----------------------------------------------------------------------
Failed to add the file /Volumes/WD 2TB External Drive/Apple Books PDFs backup/'Salem's Lot.epub to the book: /Volumes/WD 2TB External Drive/Apple Books PDFs backup/'Salem's Lot
With error:
Traceback (most recent call last):
File "calibre/gui2/add.py", line 487, in add_formats
File "calibre/db/cache.py", line 1810, in add_format
IsADirectoryError: [Errno 21] Is a directory: "/Volumes/WD 2TB External Drive/Apple Books PDFs backup/'Salem's Lot.epub"

When I click through the error, it add it to the Library, but in the TITLE column, it shows the file path where the file resides, instead of the real title. No Author information is shown.

When I double-click to open it from the Library, I get this error:

calibre, version 6.8.0
ERROR: Cannot view: /Volumes/WD 2TB External Drive/Apple Books PDFs backup/'Salem's Lot has no available formats.


Is there a way to add these ebooks back to Calibre Library?

(If there's any helpful detail I omitted, please advise)

Thank you

[Comfy.n]

I'm not familiar with macOS, but this topic may be helpful:

https://www.mobileread.com/forums/sh...d.php?t=285505

[kovidgoyal]

Those arent actual epub books but directories whose name ends with .epub. These are created by iBooks. There are some scripts floating around that can turn these back into proper epub files which you can then add to calibre.

[eBookWorm21]

Thank you.

[eBookWorm21]

Originally Posted by kovidgoyal

Those arent actual epub books but directories whose name ends with .epub. These are created by iBooks. There are some scripts floating around that can turn these back into proper epub files which you can then add to calibre.

Thank you.

I am not familiar with "scripts." Are these used with Calibre?

Also I should clarify that these EPUBs were not Apple iBooks. They were sourced elsewhere as EPUBs, then opened in Adobe Digital Editions, then added to Calibre Library. That may not have any bearing on your answer, but I am so new to this game I thought it worth adding.

Your forbearance is appreciated.

[kovidgoyal]

They are standalone scripts not part of calibre. Google something like extracting epubs from ibooks or folder epub ibooks and you should find the references.

[DNSB]

The problem is that when you copied the books to iBooks (or Books as it is now unaffectionately known), the .zip epub container was unpacked into a directory.

There is a script available on Mobileread in the ePub Zip/Unzip AppleScript application for Mac OS X thread but I'm not sure if it will still work. I did play with eCanCrusher a couple of years back and it worked on a virtual Mac.

If you use your favourite search engine for a search such as "OSX script for packing directories into epub files" comes up with quite a few hits.

[eBookWorm21]

Thanks again!

[jannik42]

Calibre expects ePub-files to be zip-compressed.

If you right-click (or control-click) on the file and get the option to "Show Package Contents", the file is actually a folder.

You can simply choose "Compress" from the context menu in Finder. This will create a "name.epub.zip" file. Now rename it to "name.epub" and add it to Calibre!

No script necessary