[smallhagrid]

Thanks JSWolf.

My collection of really old scifi alone is over 9000 titles:

Originally Posted by JSWolf

Calibre only makes ONE copy of the book you put put into it to deal with. After that, the other copies/versions are created by you can the copies/versions you don't want you can delete. So I don't see how you are forced to have copies of copies of copies by Calibre. You don't want any of the eBooks, just delete them and gone.

So the verbiage 'just delete' is quite absurd IMO here.

And thanks also PeterT:

Also; try to think of calibre as a black box; the fact it happens to store eBooks in files that you can access manually should be thought of as irrelevant. Kovid could always have selected obfuscated file names, and directory names, or even have implemented an encryption scheme on the files themselves.

For what its worth you could keep a single copy of the files OUTSIDE of calibre, and then allow calibre to manage another set for it's own purposes.

Like that garbage-ware called itunes...GACK!!!!!!!!!
You'll NOT find that horrible garbage on any of my PCs or HDDs, at all.
(I explain below how I think the 2nd-set idea is best handled - for & by me.)
Restrictive content management that encrypts, renames, etc. can go where the sun don't shine IMO - and for those who adore these programs I say:
Good for you !!! (I've been immunized, thanks.)

There is this heavy-duty confusion which I've seen a zillion times regarding the actions taken by Calibre's main program, and it goes like this:

Folks call it a 'database'.
Then for some reason they also excuse the fact that it's so-called 'database' is an entire re-structured COPY of ALL their media.
Got a GB of ebooks ? Thousands of files ?
No problem, now it's all moved around and doubled, no biggie (just an unnecessarilly excessive space-using mess).

In the purest sense, this is very mistaken; if it were to make JUST a database, it would store info, locations, etc - and leave a single copy of your stuff how & where it is as a data source ONLY.

The thinking that says 'Calibre is IT' and 'Calibre can do no wrong' is highly disagreeable to me.

When I got a Kobo, and needed to use it because the Kobo was awful for side-loading, so I actually connected a HDD externally via USB and used the portable Calibre - got the Kobo loaded, and later just formatted that HDD to purge it's mess quickly & easily.
(I kept MY original structure as I prefer it, undisturbed, thank goodness.)

Of course now my former Kobo, Kindle and others are gone because the EZReader proved to be a perfect fit for me, and it side-loads perfectly with no fuss or need for any specific program to make it take on content.

So why am I even bothering to mention a program I avoid using ?!?

Because it also does conversions, and I'm wishing there was a non-CLI way to handle it's conversion modules - this is what I posted for, and it remains what I seek even though PeterT was nice enough to help me by providing the batch code needed to convert a big batch of MOBI files I've got left over from the Kindle days.

For those who consider Calibre perfect and adore it, a tip of me olde hat; Please do pardon me if'n I stay a wall-flower (it's what I do).

Best Wishes.