[root@coolkiss ~]# who -a          【列出所有信息】
                       2011-12-29 18:44              340 id=si   term=0 exit=0
          system boot 2011-12-29 18:44
          run-level 5 2011-12-29 18:44                  last=S
                       2011-12-29 18:44             1503 id=l5   term=0 exit=0
                       2011-12-29 18:44             2454 id=1
                       2011-12-29 18:44             2455 id=2
                       2011-12-29 18:44             2456 id=3
                       2011-12-29 18:44             2457 id=4
                       2011-12-29 18:44             2458 id=5
LOGIN     tty6        2011-12-29 18:44             2459 id=6
                       2011-12-29 18:44             2460 id=x
root    ? :0          2011-12-29 18:44  ?         2608
          pts/1       2011-12-29 18:45                0 id=/1   term=0 exit=0
root    + pts/1       2011-12-30 10:01  .        15344 (10.10.10.163)
david   + pts/2       2011-12-30 10:39 00:07      15603 (10.10.10.163)
[root@coolkiss ~]# who -b          【系统最近启动的时间】
        system boot 2011-12-29 18:44
[root@coolkiss ~]# who -m          【列出当前终端信息等同于who am i 或者 whoami】
root    pts/1       2011-12-30 10:01 (10.10.10.163)
[root@coolkiss ~]# who -r          【显示当前系统的运行级别】
        run-level 5 2011-12-29 18:44                  last=S
[root@coolkiss ~]# who -u          【显示当前每个用户的用户名,登陆终端,时间,线路,标识】
root    :0          2011-12-29 18:44  ?         2608
root    pts/1       2011-12-30 10:01  .        15344 (10.10.10.163)
david   pts/2       2011-12-30 10:39 00:13      15603 (10.10.10.163)
[root@coolkiss ~]# who -buw
          system boot 2011-12-29 18:44
root    ? :0          2011-12-29 18:44  ?         2608
root    + pts/1       2011-12-30 10:01  .        15344 (10.10.10.163)
david   + pts/2       2011-12-30 10:39 00:14      15603 (10.10.10.163)