Storing metadata in file system

When saving a download to a file with curl, the --xattr option tells curl to also store certain file metadata in "extended file attributes". These extended attributes are standardized name/value pairs stored in the file system, assuming one of the supported file systems and operating systems are used.

Currently, the URL is stored in the xdg.origin.url attribute and, for HTTP, the content type is stored in the mime_type attribute. If the file system does not support extended attributes when this option is set, a warning is issued.