1. tar -x datasets.tar
tar: Refusing to read archive contents from terminal (missing -f option?)
tar: Error is not recoverable: exiting now
(retroprompt)  

tar –xvf datasets.tar 
tar: invalid option -- '�'
Try 'tar --help' or 'tar --usage' for more information.
(retroprompt) 

tar –xvf datasets.tar 
tar: invalid option -- '�'
Try 'tar --help' or 'tar --usage' for more information.
(retroprompt)

改成 tar -xf datasets.tar，成功解决