There is a WP Plugin, which is also available free of cost for basic usage here.
If you see code its is mostly PHP, JS, and CSS, but when executed it creates it own extension file → “.wpre”, which is later used in retaining the backup either on the same domain, some other domain or restoring some previous versions if backups were taken and those backups were available.
What I understand from the logical perspective is that it creates a backup of Wordpress Theme files + Database and then zip it somehow and creates extension “.wpre” How are such extensions created, and how does system understand them. It is like .php, .css or .js kind of extensions.
I have created a sample backup of a low size and w/o violating any copyrights issues. so if anyone wants to investigate the time can be saved.
I have enveloped it in the ZIP file because the system was not allowing me to upload that file extension.wpbackup-wp-1-20191129-232611-911.zip (2.7 MB)
Okay, so it’s not zip. It’s also not tar or tar.gz. There is some plain text in there, so I’m thinking some simple compression by concating everything together, like tar does? Or might be something proprietary. Not sure
