Thanks for sharing your script with us. Some remarks:
- why do you need the server-path and the folder on the server? For me it makes more sense to make a backup from an external host (like https://uriesk.wordpress.com/2015/02/13/backup-your-caldav-calendar-with-cadaver/) or just run a backup server-side script for each user (directly use the database, don’t ask the user’s password).
- Having a file with all users and clear-text passwords on the server is not good
- Tables can have a prefix different from “oc_”