Is there any way I could find out if a EPUB book is version 2.0 (2007), 3.0 (2011) or 3.1 (2015)?
djviking@box:~/Books> file -b Packt\ Publishing\ -\ Java\ 9\ High\ Performance\ \(2017\).epub
Microsoft OOXML
Not sure why it identifies the EPUB as OOXML.
Okular > Properties
MIME: application/epub+zip (application/epub+zip)
I am also using Calibre, but cannot find this information there either.
Opening the EPUB in Calibre Editor I can find the following:
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops">
Which might indicate that it is EPUB 2.0 ?
Though this URL does not exist. Perhaps this is why my Kobo Aura ONE have problem displaying their text.
I have two older books from the same publishers (which display fine) and in edit mode, the files within are not xhtml, but html and seems to be using DocBook.
<html xmlns="http://www.w3.org/1999/xhtml"><head><title>Using dataflow variables for lazy evaluation</title><link rel="stylesheet" href="epub.css" type="text/css"/><meta name="generator" content="DocBook XSL Stylesheets V1.75.2"/></head>
These older books are identified as EPUB using the file command
djviking@box:~/Books> file -b Packt\ Publishing\ -\ Groovy\ 2\ Cookbook\ \(2013\).epub
EPUB document
Edit: I think I found a program that gives me the EPUB version of the file.
djviking@box:~/Books> epubcheck Packt\ Publishing\ -\ Groovy\ 2\ Cookbook\ \(2013\).epub
Validating using EPUB version 2.0.1 rules.
No errors or warnings detected.
epubcheck completed
djviking@box:~/Books> epubcheck Packt\ Publishing\ -\ Mastering\ Java\ 9\ \(2017\).epub
Validating using EPUB version 3.0.1 rules.
No errors or warnings detected.
epubcheck completed