Backup a directory to Amazon S3, doing a full backup every month

Creates incremental, compressed, encrypted and versioned backups.
Can also upload the backups to a variety of backend services.
More information: <http://duplicity.nongnu.org>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

duplicity --full-if-older-than {{1M}} --use-new-style s3://{{bucket_name[/prefix]}}

click the source code to copy install duplicity on any operating system with command-not-found.com