I'm converting my old web project to WP and there are tons of book covers that aren't to be uploaded/managed by WP but by my own functions. Where is the right place to store such a kind of custom content? For sure it has to be a new folder but where? Maybe wp-content/uploads/cover or wp-content/cover ?
WordPress has a core function
Using this function you can retrieve all info on uploads folder base on current configuration.
E.g. if you set
If you have checked the option to store media based on current month, in WordPress settings you'll get that info too.
What I suggest is to use this function and appened the folder 'cover':
with standard settings, the
if you have year/month organization turned off, or it will be something like
if year/month organization is turned on.
In this way:
Additionally, as @Rarst said in comment, if content is being added from inside WP on ongoing basis, content uploads is nearly only place that is as likely to be easy to write to as possible (otherwise native uploads don't work). Pretty much any other place in WP install needs to go through filesystem API for reliable writes.