Identify DRMed Books in Calibre

[Bytecrawler]

I have well over five thousand ebook files (including duplicates) accumulated over 25+ years. I went though a DRM removal exercise about 15 years ago and decrypted most of the books I had then (keeping the originals), but over the years, files and folders have gotten mixed up and now I can't tell what is still encrypted and what isn't. Any of the old books that weren't decrypted are now useless - I don't have the keys or credentials any more - but I need a way to sort what is encrypted from what isn't.
I've tried loading all the files into Calibre and letting it tell me what is unreadable. In some cases, I can see right away since there is no metadata at all and the Title column just shows the file name. But for many of them, I do see metadata and the only way to know the file is still encrypted is to open it and let the reader throw an error. Does anyone have an idea how I can identify the encrypted files without opening every one of them (I suspect there is well over a thousand). The idea would be a plugin or something similar that would give me a new column with a DRM flag, but I'm open to just about any suggestion including using some other program to scan the files.

[ownedbycats]

Quality Check can identify DRM'd ePubs. Not other formats sadly.

[Quoth]

Linux can use the file command.
It's been possible since NT 4.0 to enable running Linux commands on Windows, though the things to enable it change.

This lists info on all files ending in .azw3

someone@shoebox-7050:~/some_files/eBooks_bought$ file *.azw3
A Baffling Murder at the Midsummer Ball (A Dizzy Heights Mystery).azw3:                                        Mobipocket E-book "A Baffling Murder at the Midsummer Ball", 685533 bytes uncompressed, version 8, codepage 65001, encrypted (type 2)
A BODY ON THE BEACH.azw3:                                                                                      Mobipocket E-book "A BODY ON THE BEACH a gripping Welsh crime mystery full of twists", 1246140 bytes uncompressed, version 8, codepage 65001
Above the Bay of Angels.azw3:                                                                                  Mobipocket E-book "Above the Bay of Angels", 700687 bytes uncompressed, version 8, codepage 65001, encrypted (type 2)
A Cat's Guide to Bonding with Dragons.azw3:                                                                    Mobipocket E-book "A Cat\342\200\231s Guide to Bonding with Dragons 6x9: Dragoncat Book 1", 554195 bytes uncompressed, version 8, codepage 65001, encrypted (type 2)

Can be redirected via filter for "encrypted" to a text file.

Some mobi ones. Only one is encrypted.

*.azw
Christmas Classics Cookbook.azw:                 Mobipocket E-book "Gooseberry Patch Christmas Classics", 55920 bytes uncompressed, version 6, codepage 65001
Dreamwalker (The Red Dragon Academy Book 1).azw: Mobipocket E-book "Dreamwalker (The Red Dragon Academy) (Volume 1)", 580741 bytes uncompressed, version 6, codepage 65001
The Funeral Photographer-1.azw:                  Mobipocket E-book "Number One: The Funeral Photographer", 49448 bytes uncompressed, version 6, codepage 65001, encrypted (type 2)

[theducks]

dir *.azw3 /S

is for DOS and Windows command
/S means also look in sub directories

dir /? gets you the help for ALL you can do with DIR (and it is a lot)

[fogice]

I'd put on some easy watching movies or podcasts, and just page through them. "v" to open the book, then quit the viewer, and "down arrow" to move to next book.

[Sirtel]

Or you could do a mass conversion. Books with DRM won't convert. So you won't have to press arrows all the time.

[mbovenka]

Originally Posted by Sirtel

Or you could do a mass conversion. Books with DRM won't convert. So you won't have to press arrows all the time.

The 'Count Pages' plugin will do for that as well. It won't give a pagecount for DRMed books.

[Quoth]

Originally Posted by theducks

dir *.azw3 /S

is for DOS and Windows command
/S means also look in sub directories

dir /? gets you the help for ALL you can do with DIR (and it is a lot)

Does that tell you about the files content? I thought it only listed, like "ls" on UNIX/Linux. The "file" command isn't a directory listing command, though it can do that.

[theducks]

Originally Posted by Quoth

Does that tell you about the files content? I thought it only listed, like "ls" on UNIX/Linux. The "file" command isn't a directory listing command, though it can do that.

I thought they just wanted an inventory of AZW3 (or any other type files) to run other tests on.

[Quoth]

Originally Posted by theducks

I thought they just wanted an inventory of AZW3 (or any other type files) to run other tests on.

Ah, yes, I see. Coffee shortage.