Using RSYNC (Remote Sync) to sync files from a URL is a common task that provides security and flexibility. Rsync is a powerful tool that allows you to copy and sync files both locally and remotely over the network. It is often used for backup operations, mirroring directories or files, transferring files with minimal data transfer, and more. Please note that Rsync doesn’t support sync files directly from a URL as protocols like FTP, HTTP or HTTPS are not implemented in it. But given the server that the URL points to have Rsync installed and configured properly, then you can use Rsync to sync files quite effectively (source: Isotoma Blog).
Here is a basic usage of Rsync over a network:
```
rsync -avz user@remote-host:/path/to/files /local/path
```
The `rsync` command starts the sync process, the `-a` option is for archive mode that ensures the permissions, links, file data and other attributes are preserved during the sync. `-v` stands for verbosity, `-z` stands for compression during data transfer, `user@remote-host` is the remote host where files reside and `/path/to/files` specifies the directory or files in remote host that are going to be synchronized. `/local/path` is the local path where files will be copied to. The command syncs files from remote host to the local machine (source: Tecmint).
If you need to go the other way round, from your local machine to the remote host, you swap the source and destination:
```
rsync -avz /local/path user@remote-host:/path/to/files
```
Keep in mind that Rsync only copies the differences between source and destination, so repeated operations will be quick and only transfer minimal data. If you have a large amount of data to transport but have a slow network connection, this could potentially save you a lot of time (source: Linux Handbook).
If the files’ source is a URL, Rsync can’t help you much there because it lacks the functionality to download files from a URL as tools like wget or curl do. Usually, what you need to do is download those files first using wget or curl, then use Rsync to copy or sync them as you wish.
In conclusion, while Rsync is a powerful syncing tool, it doesn’t directly support syncing files from a URL. Therefore, download the files using wget or curl and then use Rsync to perform the tasks as required.
Sources:
1. Isotoma Blog – https://www.isotoma.com/blog/2012/06/01/5-things-you-didnt-know-you-could-do-with-rsync/
2. Tecmint – https://www.tecmint.com/rsync-local-remote-file-synchronization-commands/
3. Linux Handbook – https://linuxhandbook.com/rsync-command-examples/
