EPUB Notes

Look Inside

How to get at the contents of a .epub file? Simple:

unzip foo.epub

You’ll see the HTML files that make up the EPUB file, along with some metadata.

Creating a new EPUB file

Say you want to change some things in your EPUB file - perhaps the CSS or the index. You unzipped the file and made your changes. How do you put it together into a new EPUB file?

From a look at this article, I get the idea that an EPUB file is (roughly) just a bunch of HTML files zipped the right way.

So let’s do that.

As per the instructions in that article, this is all you need:

epub_name=foo.epub

zip -X $epub_name mimetype
zip -rg $epub_name META-INF
zip -rg $epub_name * -x \*.epub META-INF mimetype

Make sure that the file doesn’t exist already, just to be safe. The mimetype file is special. Put it alone first with -X. Then, put the META-INF directory (recursively with -r). Put everything else. The -g tells zip to grow the existing archive instead of creating a new one. The -x tells zip to ignore the files you’ve already put in.