http://www.voidcn.com/blog/wszzdanm/article/p-6145895.html
命令功能：显示登录用户的信息
命令格式：
常用选项：
举例：
w 显示已经登录的用户及正在进行的操作
[root@localhost ~]# w
11:22:01 up 4 days, 21:22, 3 users, load average: 0.00, 0.00, 0.00
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root tty1 - Thu14 4days 0.19s 0.19s -bash
root pts/0 172.31.3.32 Thu14 0.00s 0.73s 0.00s w
root pts/1 172.31.3.32 11:18 1:50 0.07s 0.02s -bash
who 显示已经登录的用户名、终端名称、登录时间及登录IP
[root@localhost ~]# who
root tty1 2015-11-12 14:00
root pts/0 2015-11-12 14:03 (172.31.3.32)
root pts/1 2015-11-17 11:18 (172.31.3.32)
whoami 显示当前用户的用户名
[zzd@localhost ~]$ whoami
zzd
who am i 显示登录系统的时候的用户名，即使已经切换到其他用户也显示登录时的用户
结果同who -m
[zzd@localhost ~]$ who am i
[zzd@localhost ~]$ who -m
显示当前用户
w //显示当前用户，不显示登录位置
19:50:14 up 9:27, 4 users, load average: 0.31, 0.26, 0.18
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root tty7 :0 Thu12 31:39m 10:10 0.60s gnome-session
root pts/0 :0.0 17:09 2:18m 15.26s 0.15s bash
root pts/1 192.168.1.17 18:51 1.00s 1.24s 0.14s -bash
root pts/2 192.168.1.17 19:48 60.00s 0.05s 0.05s -bash 不显示登录位置
w -f
19:53:59 up 9:31, 4 users, load average: 0.05, 0.16, 0.15
USER TTY LOGIN@ IDLE JCPU PCPU WHAT
root tty7 Thu12 31:43m 10:10 0.60s gnome-session
root pts/0 17:09 2:21m 15.26s 0.15s bash
root pts/1 18:51 0.00s 1.04s 0.14s -bash
root pts/2 19:48 4:45 0.05s 0.05s -bash 以精简模式显示
w -s
19:54:37 up 9:31, 4 users, load average: 0.24, 0.19, 0.16
USER TTY FROM IDLE WHAT
root tty7 :0 31:43m gnome-session
root pts/0 :0.0 2:22m bash
root pts/1 192.168.1.17 0.00s -bash
root pts/2 192.168.1.17 5:23 -bash 不显示标题
w -h
root tty7 :0 Thu12 31:44m 10:10 0.60s gnome-session
root pts/0 :0.0 17:09 2:23m 15.26s 0.15s bash
root pts/1 192.168.1.17 18:51 0.00s 1.05s 0.14s -bash
root pts/2 192.168.1.17 19:48 5:54 0.05s 0.05s -bash yexiang@ubuntu:<sboot>$ w -u yexiang
14:02:04 up 9 days, 4:40, 3 users, load average: 0.99, 1.25, 0.99
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
yexiang pts/1 10.0.4.198 10:19 3.00s 0.19s 0.00s w -u yexiang