If you don't want to install, or maintain, s5cmd yourself:
ssh user@rsync.net s5cmd
Password:
NAME:
s5cmd - Blazing fast S3 and local filesystem execution tool
USAGE:
s5cmd [global options] command [command options] [arguments...]
If you move data between clouds, you don't need to use any of your own bandwidth ...
s5cmd is not listed here https://www.rsync.net/resources/howto/remote_commands.html ? :-)
It either was added in the meantime or it already was there
> Backup Tools
> attic, borg (usage notes), rclone, unison, s5cmd and git are installed (on our server side).
> You would most likely call these commands by running these tools locally and connecting to rsync.net with them.