Linux命令之last

last [-num | -n num] [-f file] [-t YYYYMMDDHHMMSS] [-R] [-adioxFw] [username..] [tty..]

  last作用是显示近期用户或终端的登录情况。通过last命令查看该程序的log,管理员可以获知谁曾经或者企图连接系统。

  执行last命令时,它会读取/var/log目录下名称为wtmp的文件,并把该文件记录的登录系统或终端的用户名单全部显示出来。默认显示wtmp的记录,btmp能显示的更详细,可以显示远程登录,例如ssh登录。

-num |-n num指定输出记录的条数
-f file 指定记录文件作为查询的log文件
-t YYYYMMDDHHMMSS 显示指定时间之前的登录情况
username 账户名称
tty 终端机编号

(1).选项

-R 不显示登录系统或终端的主机名称或IP
-a 将登录系统或终端的主机名过IP地址显示在最后一行
-d 将IP地址转成主机名称
-I 显示特定IP登录情况。
-o 读取有linux-libc5应用编写的旧类型wtmp文件
-x 显示系统关闭、用户登录和退出的历史
-F 显示登录的完整时间
-w 在输出中显示完整的用户名或域名

(2).实例

第一列:用户名

第二列:终端位置(pts/0伪终端,意味着从SSH或telnet等工具远程连接的用户,图形界面终端归于此类。tty0直接连接到计算机或本地连接的用户。后面的数字代表连接编号)

第三列:登录IP或内核(如果是:0.0或者什么都没有,意味着用户通过本地终端连接。除了重启活动,内核版本会显示在状态中)

第四列:开始时间

第五列:结束时间(still login in尚未退出,down直到正常关机,crash直到强制关机)

第六列:持续时间

指定显示记录的数量(显示记录中最后登录的数量)

[root@CentOS6 桌面]# last -n 10
root     pts/0        :0.0             Wed Apr 25 10:12   still logged in   
root     pts/1        :0.0             Wed Apr 25 10:06 - 10:10  (00:03)    
root     pts/0        :0.0             Wed Apr 25 10:06 - 10:10  (00:03)    
root     pts/0        :0.0             Wed Apr 25 10:02 - 10:06  (00:04)    
root     pts/0        :0.0             Wed Apr 25 09:51 - 09:51  (00:00)    
root     pts/0        :0.0             Wed Apr 25 09:45 - 09:51  (00:05)    
root     pts/1        :0.0             Wed Apr 25 09:38 - 09:41  (00:02)    
root     pts/0        :0.0             Wed Apr 25 09:34 - 09:45  (00:11)    
root     pts/0        :0.0             Tue Apr 17 10:46 - 10:48  (00:02)    
root     pts/0        :0.0             Tue Apr 17 10:33 - 10:46  (00:13)    
wtmp begins Tue Mar 13 18:31:47 2018
[root@CentOS6 桌面]# last -10
root     pts/0        :0.0             Wed Apr 25 10:12   still logged in   
root     pts/1        :0.0             Wed Apr 25 10:06 - 10:10  (00:03)    
root     pts/0        :0.0             Wed Apr 25 10:06 - 10:10  (00:03)    
root     pts/0        :0.0             Wed Apr 25 10:02 - 10:06  (00:04)    
root     pts/0        :0.0             Wed Apr 25 09:51 - 09:51  (00:00)    
root     pts/0        :0.0             Wed Apr 25 09:45 - 09:51  (00:05)    
root     pts/1        :0.0             Wed Apr 25 09:38 - 09:41  (00:02)    
root     pts/0        :0.0             Wed Apr 25 09:34 - 09:45  (00:11)    
root     pts/0        :0.0             Tue Apr 17 10:46 - 10:48  (00:02)    
root     pts/0        :0.0             Tue Apr 17 10:33 - 10:46  (00:13)    
wtmp begins Tue Mar 13 18:31:47 2018

 指定查询的文件,原本默认的是wtmp

[root@CentOS6 桌面]# last -10 -f /var/log/btmp
root     tty1         :0               Mon Apr 16 09:07    gone - no logout 
btmp begins Mon Apr 16 09:07:03 2018

 将IP 地址转换为主机地址

[root@CentOS6 桌面]# last -10 -d
root     pts/0        0.0.0.0          Wed Apr 25 10:12   still logged in   
root     pts/1        0.0.0.0          Wed Apr 25 10:06 - 10:10  (00:03)    
root     pts/0        0.0.0.0          Wed Apr 25 10:06 - 10:10  (00:03)    
root     pts/0        0.0.0.0          Wed Apr 25 10:02 - 10:06  (00:04)    
root     pts/0        0.0.0.0          Wed Apr 25 09:51 - 09:51  (00:00)    
root     pts/0        0.0.0.0          Wed Apr 25 09:45 - 09:51  (00:05)    
root     pts/1        0.0.0.0          Wed Apr 25 09:38 - 09:41  (00:02)    
root     pts/0        0.0.0.0          Wed Apr 25 09:34 - 09:45  (00:11)    
root     pts/0        0.0.0.0          Tue Apr 17 10:46 - 10:48  (00:02)    
root     pts/0        0.0.0.0          Tue Apr 17 10:33 - 10:46  (00:13)    
wtmp begins Tue Mar 13 18:31:47 2018

 显示指定时间之前的记录

[root@CentOS6 桌面]# last -10 -t 20180425000000  //之所以展示出来是为了提醒下-t后面的时间写法
root     pts/0        :0.0             Tue Apr 17 10:46 - 10:48  (00:02)    
root     pts/0        :0.0             Tue Apr 17 10:33 - 10:46  (00:13)    
root     pts/0        :0.0             Tue Apr 17 10:26 - 10:26  (00:00)    
root     tty2                          Tue Apr 17 10:23 - 10:23  (00:00)    
root     pts/0        :0.0             Tue Apr 17 10:22 - 10:22  (00:00)    
root     pts/0        :0.0             Tue Apr 17 10:22 - 10:22  (00:00)    
root     tty1         :0               Tue Apr 17 09:49   still logged in   
reboot   system boot  2.6.32-642.el6.x Tue Apr 17 09:48 - 10:21 (8+00:32)   
root     pts/0        :0.0             Mon Apr 16 16:13 - 16:20  (00:07)    
root     pts/0        :0.0             Mon Apr 16 15:39 - 16:13  (00:33)    
wtmp begins Tue Mar 13 18:31:47 2018

 

posted @ 2018-04-25 10:41 苦逼运维 阅读(...) 评论(...) 编辑 收藏