Who
현재 접속한 사용자 목록을 출력한다.
Example
$ who
yourname :0 2017-01-22 08:54 (:0)
yourname pts/0 2017-01-25 16:42 (:0)
servername :1 2017-01-24 09:06 (:1)
yourname pts/17 2017-01-25 21:11 (:0)
yourname pts/9 2017-01-26 12:32 (192.168.0.8)
yourname pts/26 2017-01-26 09:50 (:0.0)