用who命令可以看到用户的tty,比如是tty2
pkill -kill -t tty2
就可以踢出那个用户
$ who
ann tty7 2011-09-25 14:12 (:0)
ann pts/0 2011-09-25 14:12 (:0.0)
ann pts/1 2011-09-25 14:18 (annmato-iphone.local)
$ pkill -kill -t pts/1
$ who
ann tty7 2011-09-25 14:12 (:0)
ann pts/0 2011-09-25 14:12 (:0.0)