1、列出当前系统上所有已经登录的用户名,注意:同一个用户登录多次,则只显示一次即可。 [root@node2 ~]# who root pts/0 2016-10-08 13:28 (10.106.64.41) root pts/1 2016-10-08 13:44 (10.106.64.41) root pts/2 2016-10-08 14:22 (10.106.65.82) root pts/3 2016-10-08 14:22 (10.106.65.82) root pts/4 2016-10-08 15:26 (10.106.64.