//有关当前登录用户的信息记录在文件utmp中
//登录进入和退出纪录在文件wtmp中
[root@bogon python]# who //who命令查询utmp文件并报告当前登录的每个用户 /var/log/wtmp
root pts/0 2017-06-18 17:54 (192.168.1.100)
bp pts/1 2017-06-18 18:59 (192.168.1.100)
[root@bogon python]# users
bp root
[root@bogon python]# w //w命令查询utmp文件并显示当前系统中每个用户和它所运行的进程信息
19:00:50 up 1:07, 2 users, load average: 0.00, 0.01, 0.05
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root pts/0 192.168.1.100 17:54 2.00s 0.20s 0.03s w
bp pts/1 192.168.1.100 18:59 1:10 0.06s 0.06s -bash
[root@bogon python]# last //last命令往回搜索wtmp来显示自从文件第一次创建以来登录过的用户，还可以指定单一用户
bp pts/1 192.168.1.100 Sun Jun 18 18:59 still logged in
root pts/1 192.168.1.100 Sun Jun 18 18:58 - 18:58 (00:00)
root pts/0 192.168.1.100 Sun Jun 18 17:54 still logged in
reboot system boot 3.10.0-514.el7.x Sun Jun 18 17:52 - 19:03 (01:10)
root pts/0 192.168.1.100 Sun Jun 18 01:16 - crash (16:36)
reboot system boot 3.10.0-514.el7.x Sun Jun 18 00:53 - 19:03 (18:10)
root pts/0 192.168.1.100 Fri Jun 16 19:41 - 16:53 (21:11)
root tty1 Fri Jun 16 19:36 - 19:35 (23:58)
reboot system boot 3.10.0-514.el7.x Fri Jun 16 19:36 - 19:35 (23:59)
root pts/0 192.168.2.1 Thu Jun 15 21:36 - 10:42 (13:06)
root tty1 Thu Jun 15 21:35 - 19:35 (21:59)
reboot system boot 3.10.0-514.el7.x Thu Jun 15 21:34 - 19:35 (22:00)
root pts/0 192.168.2.1 Sun Apr 30 19:14 - 19:25 (00:11)
root tty3 Sun Apr 30 19:09 - 19:25 (00:16)
reboot system boot 3.10.0-514.el7.x Sun Apr 30 19:08 - 19:25 (00:17)
root pts/1 192.168.2.1 Sun Apr 30 07:12 - down (11:56)
root pts/0 :0 Sun Apr 30 07:08 - 19:08 (11:59)
root :0 :0 Sun Apr 30 07:08 - 19:08 (11:59)
(unknown :0 :0 Sun Apr 30 07:08 - 07:08 (00:00)
bp pts/0 :0 Sun Apr 30 07:00 - 07:08 (00:07)
bp pts/0 :0 Sun Apr 30 06:59 - 06:59 (00:00)
bp :0 :0 Sun Apr 30 06:55 - 07:08 (00:12)
(unknown :0 :0 Sun Apr 30 06:55 - 06:55 (00:00)
reboot system boot 3.10.0-514.el7.x Sun Apr 30 02:53 - 19:08 (16:15)
wtmp begins Sun Apr 30 02:53:13 2017
[root@bogon python]# ac //统计累计在线时间
total 118.31
[root@bogon python]# ac root
total 117.86
[root@bogon python]# ac bp
total 0.45
[root@bogon python]# ac -d //统计每天的
Apr 30 total 36.73
Jun 15 total 4.80
Jun 16 total 39.00
Jun 17 total 36.48
Today total 1.33
